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Nikkor 12-24 vs. Canon 10-22

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March 8, 2005 12:19:14 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Finally I am going to switch from film totally. I am to either go
Canon or Nikon and totally based on this WA question. I will do 85% of
my work with the WA lens. My work is crime scenes. Mostly alleys and
interiors ... some at night. I prefer not using flash and rather use a
tripod when necessary.

Which lens is better with regards to sharpness and lack of distortion?
Not having a big budget, it is going to be D70 or Rebel XT based
solely on this lens choice.

Thank you all for any input.

Marty

More about : nikkor canon

Anonymous
March 8, 2005 7:04:49 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Marty wrote:

<snip>

> Which lens is better with regards to sharpness and lack of
distortion?

<snip>

Both of these lense are about the same level. The advantage of the EF-s
10-22 is that it's available for about $300 less. I paid around $625
for it, while the Nikon 12-24 is about $930.

Since you may be shooting at higher ISO settings, due to the lack of a
flash, you probably should go Canon, rather than Nikon, since the Canon
has lower noise at the higher ISO settings.

Really either one would be fine. The D70 body will be cheaper, since
there are rebates on it now as it is about to be replaced by a newer
model, but the Rebel xt will be cheaper for the body plus wide-angle
lens.

Steve
http://digitalslrinfo.com
Anonymous
March 8, 2005 10:00:24 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Seems the topic wandered to something you did not ask for. For me I would
go with the Nikon. I have a 12-24 and find it quite good. Have never
compared the results with a Canon 10-22. I owned a Canon Video that used
interchangeable lens. I spend a great deal on my Canon Lens system only to
junk them all within two years. They grew fungus internally and were
useless. My 35 year old Nikon lenses which I packed all over the Pacific
Islands in some very adverse weather conditions are still perfect. It's
Nikon for me when compared to Canon based on my personal experience.


"Marty" <ehasz@ix.netcom.com> wrote in message
news:a2rq2115ol7d7m2lt67m07s076i5mj98ih@4ax.com...
> Finally I am going to switch from film totally. I am to either go
> Canon or Nikon and totally based on this WA question. I will do 85% of
> my work with the WA lens. My work is crime scenes. Mostly alleys and
> interiors ... some at night. I prefer not using flash and rather use a
> tripod when necessary.
>
> Which lens is better with regards to sharpness and lack of distortion?
> Not having a big budget, it is going to be D70 or Rebel XT based
> solely on this lens choice.
>
> Thank you all for any input.
>
> Marty
Related resources
Anonymous
March 8, 2005 10:53:57 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

"Scharf-DCA" <scharf.steven@gmail.com> wrote in message
news:1110326689.658138.234620@o13g2000cwo.googlegroups.com...
> Since you may be shooting at higher ISO settings, due to the lack of a
> flash, you probably should go Canon, rather than Nikon, since the Canon
> has lower noise at the higher ISO settings.
>

I believe the OP indicated a preference for tripod-mounted long exposures,
not high ISO settings. Marty, is a little more digital noise going to
impact your work as a crime scene photographer?

Walt
March 9, 2005 2:45:22 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Tue, 08 Mar 2005 19:00:24 GMT, "IMKen" <imken@hawaii.rr.com> wrote:

>Seems the topic wandered to something you did not ask for. For me I would
>go with the Nikon. I have a 12-24 and find it quite good. Have never
>compared the results with a Canon 10-22. I owned a Canon Video that used
>interchangeable lens. I spend a great deal on my Canon Lens system only to
>junk them all within two years. They grew fungus internally and were
>useless. My 35 year old Nikon lenses which I packed all over the Pacific
>Islands in some very adverse weather conditions are still perfect. It's
>Nikon for me when compared to Canon based on my personal experience.
>
>
>"Marty" <ehasz@ix.netcom.com> wrote in message
>news:a2rq2115ol7d7m2lt67m07s076i5mj98ih@4ax.com...
>> Finally I am going to switch from film totally. I am to either go
>> Canon or Nikon and totally based on this WA question. I will do 85% of
>> my work with the WA lens. My work is crime scenes. Mostly alleys and
>> interiors ... some at night. I prefer not using flash and rather use a
>> tripod when necessary.
>>
>> Which lens is better with regards to sharpness and lack of distortion?
>> Not having a big budget, it is going to be D70 or Rebel XT based
>> solely on this lens choice.
>>
>> Thank you all for any input.
>>
>> Marty
>

Right you are IMKen. I think I like the D70 better than the Canon XT
or 20d. My experience with Canon is from 1966 and I had to problem. I
had Nikons in quantity after that and also had no problem. However I
then switched to all Leica rangefinders for a decade. They were my
loves. Today I couldn't afford even one of them. Thanks again.
Anonymous
March 9, 2005 2:49:26 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Marty wrote:
>
> Finally I am going to switch from film totally. I am to either go
> Canon or Nikon and totally based on this WA question. I will do 85% of
> my work with the WA lens. My work is crime scenes. Mostly alleys and
> interiors ... some at night. I prefer not using flash and rather use a
> tripod when necessary.
>
> Which lens is better with regards to sharpness and lack of distortion?
> Not having a big budget, it is going to be D70 or Rebel XT based
> solely on this lens choice.
>
> Thank you all for any input.
>
> Marty

I don't now whether you do this 'officially' for police or legal
reasons, but if you will be in a position to rely on your shots as
evidence in a court, you may be called on to prove the authenticity of
your pictures. A negative is generally regarded as incontrovertible
proof of authenticity, but the ease with which digital images can be
tampered with generally means it is harder to prove the image as
genuine.

Canon is working on (may have it on the market now, as I haven't been
following the progress) a system that will be proof of authenticity for
a digital image, for the reasons outlined above. I am unaware of any
move in that direction by Nikon, or any other maker of digital cameras.

This may well dictate your choice of camera, and hence lens.

Colin
March 9, 2005 2:49:27 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Tue, 08 Mar 2005 23:49:26 +1300, Colin D
<ColinD@killspam.127.0.0.1> wrote:

>
>
>Marty wrote:
>>
>> Finally I am going to switch from film totally. I am to either go
>> Canon or Nikon and totally based on this WA question. I will do 85% of
>> my work with the WA lens. My work is crime scenes. Mostly alleys and
>> interiors ... some at night. I prefer not using flash and rather use a
>> tripod when necessary.
>>
>> Which lens is better with regards to sharpness and lack of distortion?
>> Not having a big budget, it is going to be D70 or Rebel XT based
>> solely on this lens choice.
>>
>> Thank you all for any input.
>>
>> Marty
>
>I don't now whether you do this 'officially' for police or legal
>reasons, but if you will be in a position to rely on your shots as
>evidence in a court, you may be called on to prove the authenticity of
>your pictures. A negative is generally regarded as incontrovertible
>proof of authenticity, but the ease with which digital images can be
>tampered with generally means it is harder to prove the image as
>genuine.
>
>Canon is working on (may have it on the market now, as I haven't been
>following the progress) a system that will be proof of authenticity for
>a digital image, for the reasons outlined above. I am unaware of any
>move in that direction by Nikon, or any other maker of digital cameras.
>
>This may well dictate your choice of camera, and hence lens.
>
>Colin

Thank you. I do use the stuff in homicide defense cases ... mostly
death penalty. I have been doing this for about forty years as a cop
first and defense after that. (I am pretty old.) The standard here in
Maryland is that the picture fairly and accurately represents the
scene as it was observed by the photographer. I have never been asked
for a negative ... yet. Nor have I been asked if the photos were made
using film or digital. I have, during the past two years, used some
digital p&s without question so far.

Thanks again for your input.
Anonymous
March 9, 2005 2:49:27 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Tue, 08 Mar 2005 23:49:26 +1300, Colin D <ColinD@killspam.127.0.0.1> wrote:
>
> Canon is working on (may have it on the market now, as I haven't been
> following the progress) a system that will be proof of authenticity for
> a digital image, for the reasons outlined above.

It's out there; in its second version, even. The part is the DVK-E2.
The press release says it works with the 1Ds and the 1D MkII. I'd
guess it works with the 1Ds MkII as well. Somewhere on dpreview, it
says that this thing works with the 20D, but I have a 20D and I
don't believe that that's correct.

http://www.dpreview.com/news/0401/04012903canondvke2.as...

I was awfully chagrined when the DVK-E2's release was covered on
Slashdot about a year ago, as I had been working for several months
on a nearly identical invention. Canon and I even identified the
same target markets: news, law enforcement, insurance, and spies --
though they didn't mention spies in their press release. :-)

The patent, it turns out, dates from 1999 or thereabouts. So I
wasn't even close.

--
Ben Rosengart (212) 741-4400 x215
Sometimes it only makes sense to focus our attention on those
questions that are equal parts trivial and intriguing.
--Josh Micah Marshall
March 9, 2005 2:49:27 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

"Colin D" <ColinD@killspam.127.0.0.1> wrote in message
news:422D8336.DBD84073@killspam.127.0.0.1...
>
>
> Marty wrote:
> >
> > Finally I am going to switch from film totally. I am to either go
> > Canon or Nikon and totally based on this WA question. I will do 85% of
> > my work with the WA lens. My work is crime scenes. Mostly alleys and
> > interiors ... some at night. I prefer not using flash and rather use a
> > tripod when necessary.
> >
> > Which lens is better with regards to sharpness and lack of distortion?
> > Not having a big budget, it is going to be D70 or Rebel XT based
> > solely on this lens choice.
> >
> > Thank you all for any input.
> >
> > Marty
>
> I don't now whether you do this 'officially' for police or legal
> reasons, but if you will be in a position to rely on your shots as
> evidence in a court, you may be called on to prove the authenticity of
> your pictures. A negative is generally regarded as incontrovertible
> proof of authenticity, but the ease with which digital images can be
> tampered with generally means it is harder to prove the image as
> genuine.
>
> Canon is working on (may have it on the market now, as I haven't been
> following the progress) a system that will be proof of authenticity for
> a digital image, for the reasons outlined above. I am unaware of any
> move in that direction by Nikon, or any other maker of digital cameras.
>
> This may well dictate your choice of camera, and hence lens.
>
> Colin

Since one can always use a digital camera and a film recorder the legal
system has me bewildered!

George
Anonymous
March 9, 2005 2:49:27 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Tue, 08 Mar 2005 23:49:26 +1300, Colin D
<ColinD@killspam.127.0.0.1> wrote:

>I don't now whether you do this 'officially' for police or legal
>reasons, but if you will be in a position to rely on your shots as
>evidence in a court, you may be called on to prove the authenticity of
>your pictures. A negative is generally regarded as incontrovertible
>proof of authenticity, but the ease with which digital images can be
>tampered with generally means it is harder to prove the image as
>genuine.

I have been hearing this stuff for years now. Most of the major
police forces here in Canada have already switched to digital, in fact
there was an article in Photo District News last year about the
Winnipeg Police and RCMP using digital only, and I know that the
Ontario Provincial Police uses digital imagery interchangeably with
film. All the forensic technician or photographer is required to do,
if asked, is testify that the image represents the scene as he saw
it. The same thing they were asked to do with film. In my entire
career I have never heard of a photographer having to produce a
negative in court.
Anonymous
March 9, 2005 2:49:28 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Op Tue, 8 Mar 2005 15:43:20 +0000 (UTC) schreef Ben Rosengart
<br+rpdss@panix.com>:

>t's out there; in its second version, even. The part is the DVK-E2.
>The press release says it works with the 1Ds and the 1D MkII. I'd
>guess it works with the 1Ds MkII as well. Somewhere on dpreview, it
>says that this thing works with the 20D, but I have a 20D and I
>don't believe that that's correct.

From the website of B&H:

The Canon EOS-1Ds Mark II and EOS 20D digital cameras can prove it's
images are unaltered, original files. The Data Verification Kit
DVK-E2, consisting of a dedicated memory card, a Secure Mobile (SM)
card reader, and special software for Windows 2000/XP is able to
verify that EOS-1Ds Mark II and EOS 20D image files are absolutely
unaltered. The system is so precise, that even the slightest
discrepancy is detected. This may well be a landmark for digital
imaging in law enforcement and other documentary uses.

When the EOS-1Ds Mark II and EOS 20D user shoots with the verification
system activated (P.Fn-31), a code is automatically generated based on
the image contents and attached to the image. When the image is
viewed, the data verification software determines the code for the
image and compares it with the attached code. If the photo has been
retouched in any way, the codes will not match, thus verifying that
the image is not the original.
you can send email to me using
mendelson-at-mendelson-dot-nl
www.mendelson.nl
Anonymous
March 9, 2005 2:49:28 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

FWIW:
Canon's "data verification kit" has been available for quite a while. I've
seen a web page on it, and a magazine (web) article on it, but I just went
to the Canon USA web site ... and their search capabilities are soo anemic
that you will have a hard time finding it. The "official" name is "Canon
Data Verification Kit DVK-E2."

http://www.dpreview.com/news/0401/04012903canondvke2.as...

http://www.adorama.com/ICADVKE1.html

http://www.bhphotovideo.com/product/266214/CADVKE1/REG/...

http://www.canoncompanystore.com/epages/annex.storefron...







"Marty" <ehasz@ix.netcom.com> wrote in message
news:ai1r219u6kh3rvorsdaemvu9g6msnmfqkj@4ax.com...
> On Tue, 08 Mar 2005 23:49:26 +1300, Colin D
> <ColinD@killspam.127.0.0.1> wrote:
>
> >
> >
> >Marty wrote:
> >>
> >> Finally I am going to switch from film totally. I am to either go
> >> Canon or Nikon and totally based on this WA question. I will do 85% of
> >> my work with the WA lens. My work is crime scenes. Mostly alleys and
> >> interiors ... some at night. I prefer not using flash and rather use a
> >> tripod when necessary.
> >>
> >> Which lens is better with regards to sharpness and lack of distortion?
> >> Not having a big budget, it is going to be D70 or Rebel XT based
> >> solely on this lens choice.
> >>
> >> Thank you all for any input.
> >>
> >> Marty
> >
> >I don't now whether you do this 'officially' for police or legal
> >reasons, but if you will be in a position to rely on your shots as
> >evidence in a court, you may be called on to prove the authenticity of
> >your pictures. A negative is generally regarded as incontrovertible
> >proof of authenticity, but the ease with which digital images can be
> >tampered with generally means it is harder to prove the image as
> >genuine.
> >
> >Canon is working on (may have it on the market now, as I haven't been
> >following the progress) a system that will be proof of authenticity for
> >a digital image, for the reasons outlined above. I am unaware of any
> >move in that direction by Nikon, or any other maker of digital cameras.
> >
> >This may well dictate your choice of camera, and hence lens.
> >
> >Colin
>
> Thank you. I do use the stuff in homicide defense cases ... mostly
> death penalty. I have been doing this for about forty years as a cop
> first and defense after that. (I am pretty old.) The standard here in
> Maryland is that the picture fairly and accurately represents the
> scene as it was observed by the photographer. I have never been asked
> for a negative ... yet. Nor have I been asked if the photos were made
> using film or digital. I have, during the past two years, used some
> digital p&s without question so far.
>
> Thanks again for your input.
March 9, 2005 2:49:28 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Tue, 08 Mar 2005 15:46:08 -0500, McLeod <cerdeza@xplornet.com>
wrote:

>On Tue, 08 Mar 2005 23:49:26 +1300, Colin D
><ColinD@killspam.127.0.0.1> wrote:
>
>>I don't now whether you do this 'officially' for police or legal
>>reasons, but if you will be in a position to rely on your shots as
>>evidence in a court, you may be called on to prove the authenticity of
>>your pictures. A negative is generally regarded as incontrovertible
>>proof of authenticity, but the ease with which digital images can be
>>tampered with generally means it is harder to prove the image as
>>genuine.
>
>I have been hearing this stuff for years now. Most of the major
>police forces here in Canada have already switched to digital, in fact
>there was an article in Photo District News last year about the
>Winnipeg Police and RCMP using digital only, and I know that the
>Ontario Provincial Police uses digital imagery interchangeably with
>film. All the forensic technician or photographer is required to do,
>if asked, is testify that the image represents the scene as he saw
>it. The same thing they were asked to do with film. In my entire
>career I have never heard of a photographer having to produce a
>negative in court.

Thank you McLeod. I have been in court for 40 years myself and also
have not had to produce any negatives. In the old days I used a 4x5
Speed Graphic and recorded f-stops, shutter speeds, film, developer,
etc. No one ever asked me about that stuff either. My photos usually
have to do with a view someone says they had. That is, an impossible
view. Thus, if someone doubts my pictures and testimony they only need
to go out to the scene for themselves. Usually it has something to do
with police or government witnesses having amazing x-ray vision ... or
the ability to see around corners. :) 

As I said way above, in Maryland we are asked if the photograph
"fairly and accurately represents the scene" ... very similar to
Canada I now know.

Marty
Anonymous
March 9, 2005 2:49:29 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Tue, 08 Mar 2005 16:54:11 +0100, bart j mendelson <mendels@xs4all.nl> wrote:
>
> From the website of B&H:
> [...]
>
> When the EOS-1Ds Mark II and EOS 20D user shoots with the verification
> system activated (P.Fn-31),

The 20D doesn't have "personal functions", it has "custom functions",
and they only go up to 18. I've looked at all of them and none is
for data verification.

--
Ben Rosengart (212) 741-4400 x215
Sometimes it only makes sense to focus our attention on those
questions that are equal parts trivial and intriguing.
--Josh Micah Marshall
Anonymous
March 9, 2005 2:49:29 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <ljir21l7v0rdj8ql71bdq4ptmu5p7qf7kb@4ax.com>,
bart j mendelson <mendels@xs4all.nl> wrote:
>From the website of B&H:
>
>The Canon EOS-1Ds Mark II and EOS 20D digital cameras can prove it's
>images are unaltered, original files. The Data Verification Kit
>DVK-E2, consisting of a dedicated memory card, a Secure Mobile (SM)
>card reader, and special software for Windows 2000/XP is able to
>verify that EOS-1Ds Mark II and EOS 20D image files are absolutely
>unaltered. The system is so precise, that even the slightest
>discrepancy is detected. This may well be a landmark for digital
>imaging in law enforcement and other documentary uses.

In the crypto world this is usually called a digital signature.

The easiest way to do this is give each camera a small piece of
temperistant storage (for the key), and a certificate for the key.
(And updated firmware to compute signatures).

No need for a dedicated memory card, or a secure card reader.

The tricky part is of course to make sure that the key is well protected.

(Given the decicated memory card and the secure card reader, it is possible
that the actual digital signature is computed in the secure card reader,
and that before that a less secure scheme is used. A MAC between the
camera and the secure card reader is also possible, but that does not
require a dedicated card. The deciated card suggests that the card
recognizes the camera, that camera does not do anything special,
and that the secure card reader recognizes the card and computes the
signature.)


--
That was it. Done. The faulty Monk was turned out into the desert where it
could believe what it liked, including the idea that it bad been done by.
It was allowed to keep its horse, since horses where so cheap to make.
-- Douglas Adams in Dirk Gently's Holistic Detective Agency
Anonymous
March 9, 2005 2:49:29 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

"RSD99" <rsdwla.NOSPAM@gte.net> wrote in message
news:nDqXd.29492$uc.8493@trnddc09...
> FWIW:
> Canon's "data verification kit" has been available for quite a while. I've
> seen a web page on it, and a magazine (web) article on it, but I just went
> to the Canon USA web site ... and their search capabilities are soo anemic
> that you will have a hard time finding it. The "official" name is "Canon
> Data Verification Kit DVK-E2."
>

Based on what Marty and McLeod (the working pros in this area) have both
indicated, this would appear to be another solution for a problem that
doesn't exist.

Walt
Anonymous
March 9, 2005 2:49:30 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Op Tue, 8 Mar 2005 16:01:43 +0000 (UTC) schreef Ben Rosengart
<br+rpdss@panix.com>:

>On Tue, 08 Mar 2005 16:54:11 +0100, bart j mendelson <mendels@xs4all.nl> wrote:
>>
>> From the website of B&H:
>> [...]
>>
>> When the EOS-1Ds Mark II and EOS 20D user shoots with the verification
>> system activated (P.Fn-31),
>
>The 20D doesn't have "personal functions", it has "custom functions",
>and they only go up to 18. I've looked at all of them and none is
>for data verification.

Then the B&H website must be wrong. And so is amazon:
http://www.amazon.com/exec/obidos/tg/detail/-/B0002XQJF....

>Additional Accessories
In addition to Canon's EF series of lenses and Speedlites, several
other accessories are designed to work specifically with the EOS 20D.
The Battery Grip BG-E2 adds a vertical shutter release, and is
compatible with up to two of Canon's BP-511/511A/512/514 lithium-ion
battery packs, or alternatively a set of six AA batteries, for greater
convenience when traveling. Canon's Semi Hard Case EH/7-L can
accommodate the EOS 20D with a small zoom lens (EF-S17-85mm f4-5.6 IS
USM included), and the EOS 20D is compatible with Canon's DVK-E2 image
data verification kit to check original image data authenticity,
whenever verification is essential.

and http://www.dpreview.com/news/0408/04081909canon_eos20d....

and http://www.canon.ru/products/about.asp?id=1298

?????? EOS 20D ?????????? ? ????????????? ????????????? ?????????? ???
???????? ?????? DVK-E2, ??????? ??????????? ? ?????? ?????????
????????, ? ??????? ? ? ??????????? ?????? ??? ???????? ???????????
?????? ???? ??????? ???????????.

and: http://www.canon.lt/products/about.asp?id=1298

and
http://www.canon.co.uk/about_us/news/consumer_releases/...

and: http://www.canon.com.ph/inpage.asp?mainContent=327

and:
http://consumer.usa.canon.com/ir/controller?act=SNAMode...

and finally from canon USA:
Data Verification Kit DVK-E2
9314A001AA

In Stock
Price: $1,100.00
Like its predecessor, this kit can verify whether or not a photo is an
untouched original. But its use of a Secure Mobile (SM) card reader,
instead of an IC card reader, makes it more compact than the previous
version. Moreover, the versatile DVK-E2 is able to verify images
photographed by the EOS-1Ds as long as they are appended with a data
verification image.
Includes card reader, IC card, Software CD.

Models:
EOS 1D Mark II, EOS 20D, EOS 1DS

end of list and quotes.

But how it works? I don't know, i don't own a 20D yet.

Bart


you can send email to me using
mendelson-at-mendelson-dot-nl
www.mendelson.nl
Anonymous
March 9, 2005 2:49:30 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <v7blpefibcdmg38pt1b5hdclr0@inews_id.stereo.hq.phicoh.net>,
Philip Homburg <philip@pch.home.cs.vu.nl> wrote:
>In article <ljir21l7v0rdj8ql71bdq4ptmu5p7qf7kb@4ax.com>,
>bart j mendelson <mendels@xs4all.nl> wrote:
>>From the website of B&H:
>>
>>The Canon EOS-1Ds Mark II and EOS 20D digital cameras can prove it's
>>images are unaltered, original files. The Data Verification Kit
>>DVK-E2, consisting of a dedicated memory card, a Secure Mobile (SM)
>>card reader, and special software for Windows 2000/XP is able to
>>verify that EOS-1Ds Mark II and EOS 20D image files are absolutely
>>unaltered. The system is so precise, that even the slightest
>>discrepancy is detected. This may well be a landmark for digital
>>imaging in law enforcement and other documentary uses.
>
>In the crypto world this is usually called a digital signature.
>
>The easiest way to do this is give each camera a small piece of
>temperistant storage (for the key), and a certificate for the key.
>(And updated firmware to compute signatures).
>
>No need for a dedicated memory card, or a secure card reader.
>
>The tricky part is of course to make sure that the key is well protected.

It would be simple enough to use a MD5 hash of a combination of
the image and the camera's model number and serial number -- plus a
private key hidden in the camera. This should suffice for a signature.
(Hmm ... toss in the date too -- so that can be verified as well --
compare the date stored in the image's info fields with that rolled into
the MD5 hash, so a photo taken later could not be substituted.)

>(Given the decicated memory card and the secure card reader, it is possible
>that the actual digital signature is computed in the secure card reader,
>and that before that a less secure scheme is used. A MAC between the
>camera and the secure card reader is also possible, but that does not
>require a dedicated card. The deciated card suggests that the card
>recognizes the camera, that camera does not do anything special,
>and that the secure card reader recognizes the card and computes the
>signature.)

The card could contain its own serial number, too. I presume
that such are available on flash cards. They are certainly encoded in
modern SCSI drives, and can be read by the system.

Of course, something like PGP (or some other
private-key/public-key cipher) would be better (more secure), but that
would require more processing power in the camera -- perhaps taking the
frame rate down to something like one frame per minute. :-)

O.K. On a 300 MHz Ultra-SPARC CPU, a md5 hash of a 1.5 MB JPEG
image takes:

0.06u 0.04s 0:00.17 58.8%

that is -- 60 mS of user time,
40 mS of system time,
or 0.17 seconds of wall clock time, with the CPU having
58.8% of the system's resources at the time.

A similarly fast and capable CPU in the camera would take something
closer to the sum of the first two -- or 100 mS (0.1 seconds).

A PGP signature would take somewhat longer, and a full PGP
encryption of the entire file would take significantly longer -- so it
depends on how much security you need -- and how much you are willing to
accept that the encrypted image may become unrecoverable from a single
bit error near the beginning. :-) I think that the PGP signature would
be the best, with a private key in the camera (or the flash card), and a
public key in the reader for verification. That way, it would not
matter whether the reader was destroyed, as long as a record of the
public key was available. And -- there is no real reason to keep the
public key secret, so *anyone* could verify a copy of the image.

Enjoy,
DoN.
--
Email: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---
Anonymous
March 9, 2005 2:49:31 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Tue, 08 Mar 2005 17:37:04 +0100, bart j mendelson <mendels@xs4all.nl> wrote:
> Op Tue, 8 Mar 2005 16:01:43 +0000 (UTC) schreef Ben Rosengart
><br+rpdss@panix.com>:
>
>>The 20D doesn't have "personal functions", it has "custom functions",
>>and they only go up to 18. I've looked at all of them and none is
>>for data verification.
>
> Then the B&H website must be wrong. And so is amazon:
> [...]

Five bazillion vendors plus Canon themselves can't be wrong, eh?
I just checked the manual. The hitherto-mysterious Custom Function
18, "Add original decision data," is indeed for use with the DVK-E2.
Sorry for spreading misinformation, and thanks for setting me straight!

--
Ben Rosengart (212) 741-4400 x215
Sometimes it only makes sense to focus our attention on those
questions that are equal parts trivial and intriguing.
--Josh Micah Marshall
Anonymous
March 9, 2005 2:49:32 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Op Tue, 8 Mar 2005 16:47:08 +0000 (UTC) schreef Ben Rosengart
<br+rpdss@panix.com>:

>On Tue, 08 Mar 2005 17:37:04 +0100, bart j mendelson <mendels@xs4all.nl> wrote:
>> Op Tue, 8 Mar 2005 16:01:43 +0000 (UTC) schreef Ben Rosengart
>><br+rpdss@panix.com>:
>>
>>>The 20D doesn't have "personal functions", it has "custom functions",
>>>and they only go up to 18. I've looked at all of them and none is
>>>for data verification.
>>
>> Then the B&H website must be wrong. And so is amazon:
>> [...]
>
>Five bazillion vendors plus Canon themselves can't be wrong, eh?

Not only vendors but also the always correct Canon Lituania :-) !
you can send email to me using
mendelson-at-mendelson-dot-nl
www.mendelson.nl
Anonymous
March 9, 2005 4:19:04 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Tue, 8 Mar 2005 20:00:43 -0500, Walt Hanks <walthanks@comcast.net> wrote:
>
> Based on what Marty and McLeod (the working pros in this area) have both
> indicated, this would appear to be another solution for a problem that
> doesn't exist.

Legal systems move slowly (as they should). Society is still
figuring out how seriously to take cryptographic evidence. Perhaps
it will take an unusual case to establish the admissibility of this
kind of cryptographic evidence. Like one where the facts are hotly
contested and the photographer is dead or otherwise unavailable.
I'm not holding my breath. But it's a cool idea and I do think it
deserves and will some day see its day in the sun.

--
Ben Rosengart (212) 741-4400 x215
Sometimes it only makes sense to focus our attention on those
questions that are equal parts trivial and intriguing.
--Josh Micah Marshall
Anonymous
March 9, 2005 5:55:02 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <CKCdnTmL6cgl17PfRVn-vQ@comcast.com>, walthanks@comcast.net
says...
> Based on what Marty and McLeod (the working pros in this area) have both
> indicated, this would appear to be another solution for a problem that
> doesn't exist.
>
> Walt

It might exist someday. Wait until some circumstance arises where a
defense lawyer has an opportunity to call the photo into question.
Anonymous
March 9, 2005 5:55:03 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

"Brian C. Baird" <nospam@please.no> wrote in message
news:MPG.1c982f95d66b118998a7b4@news.verizon.net...
> In article <CKCdnTmL6cgl17PfRVn-vQ@comcast.com>, walthanks@comcast.net
> says...
>> Based on what Marty and McLeod (the working pros in this area) have both
>> indicated, this would appear to be another solution for a problem that
>> doesn't exist.
>>
>> Walt
>
> It might exist someday. Wait until some circumstance arises where a
> defense lawyer has an opportunity to call the photo into question

It would take an incredibly big case and clear alteration of evidence to get
long-standing legal precedent set aside.

Walt
March 9, 2005 6:09:26 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Tue, 8 Mar 2005 19:53:57 -0500, "Walt Hanks"
<walthanks@comcast.net> wrote:

>
>"Scharf-DCA" <scharf.steven@gmail.com> wrote in message
>news:1110326689.658138.234620@o13g2000cwo.googlegroups.com...
>> Since you may be shooting at higher ISO settings, due to the lack of a
>> flash, you probably should go Canon, rather than Nikon, since the Canon
>> has lower noise at the higher ISO settings.
>>
>
>I believe the OP indicated a preference for tripod-mounted long exposures,
>not high ISO settings. Marty, is a little more digital noise going to
>impact your work as a crime scene photographer?
>
>Walt
>
>

Walt,

Actually I prefer high ISO, but tripod rather than flash. Last year I
did one site which had very weak street lighting (using a
tripod/self-timer with a mid range p&s) and had extremely high noise.
Still, it was good enough to show the lighting situation. Its mostly a
matter of pride that I want to reduce the noise as much as possible.
Also, I was recently insulted by a street drug dealer who had a better
camera than I did. :) 

Marty
Anonymous
March 9, 2005 6:09:27 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

"Marty" <ehasz@ix.netcom.com> wrote in message
news:rnps21l17i4l9k0qbhi46h0mmi1g2k751v@4ax.com...
> Walt,
>
> Actually I prefer high ISO, but tripod rather than flash. Last year I
> did one site which had very weak street lighting (using a
> tripod/self-timer with a mid range p&s) and had extremely high noise.
> Still, it was good enough to show the lighting situation. Its mostly a
> matter of pride that I want to reduce the noise as much as possible.
> Also, I was recently insulted by a street drug dealer who had a better
> camera than I did. :) 
>
> Marty
>

Let me guess, Charles between Penn Station and North Ave? <g>

Let us know what you decide to get. You might consider renting both for a
day or two to see how they feel for you. I think that Service Photo (my
favorite shutter shack) rents both systems. Just don't get Abe started on
the Nikon/Canon stuff though. You'll be there for hours.

Walt
March 9, 2005 6:36:13 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Walt Hanks wrote:
> "Brian C. Baird" <nospam@please.no> wrote in message
> news:MPG.1c982f95d66b118998a7b4@news.verizon.net...
>
>>In article <CKCdnTmL6cgl17PfRVn-vQ@comcast.com>, walthanks@comcast.net
>>says...
>>
>>>Based on what Marty and McLeod (the working pros in this area) have both
>>>indicated, this would appear to be another solution for a problem that
>>>doesn't exist.
>>>
>>>Walt
>>
>>It might exist someday. Wait until some circumstance arises where a
>>defense lawyer has an opportunity to call the photo into question
>
>
> It would take an incredibly big case and clear alteration of evidence to get
> long-standing legal precedent set aside.
>
> Walt


Well, it can still happen despite how slim the chances might be. The
lawyers should start to get ready to prove their photographic evidents.
Anonymous
March 9, 2005 6:38:01 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On 8 Mar 2005 22:04:13 -0500, DoN. Nichols <dnichols@d-and-d.com> wrote:
>
> It would be simple enough to use a MD5 hash of a combination of
> the image and the camera's model number and serial number -- plus a
> private key hidden in the camera. This should suffice for a signature.
> (Hmm ... toss in the date too -- so that can be verified as well --
> compare the date stored in the image's info fields with that rolled into
> the MD5 hash, so a photo taken later could not be substituted.)

Make it SHA-256, in light of the recently discovered flaws in MD5
and SHA-1. And how about tossing in GPS info as well?

:-)

> Of course, something like PGP (or some other
> private-key/public-key cipher) would be better (more secure), but that
> would require more processing power in the camera -- perhaps taking the
> frame rate down to something like one frame per minute. :-)

You weren't speaking of a public-key system when you referred to a
"private key"?

> O.K. On a 300 MHz Ultra-SPARC CPU, a md5 hash of a 1.5 MB JPEG
> image takes:

I think the expensive part is the public-key math -- which is still
not so bad since you're only signing a hash, not the message itself.
(Ok, I'm handwaving here, I'm not actually sure which is more costly.)

> A PGP signature would take somewhat longer, and a full PGP
> encryption of the entire file would take significantly longer

There's also no real reason to do that.

> -- so it
> depends on how much security you need -- and how much you are willing to
> accept that the encrypted image may become unrecoverable from a single
> bit error near the beginning. :-) I think that the PGP signature would
> be the best, with a private key in the camera (or the flash card), and a
> public key in the reader for verification.

Agreed, though it could just as easily be x.509.

As my friend Thor pointed out to me when I was working on this,
you can include the camera public key in the signed image, if you
sign it with the vendor's private key. Then there's only one public
key that everyone needs: the vendor's.

I have some very nice diagrams of all of this that I commissioned
when I still thought I was going to apply for a patent. :-) Talk
about your expensive mistakes.

--
Ben Rosengart (212) 741-4400 x215
Sometimes it only makes sense to focus our attention on those
questions that are equal parts trivial and intriguing.
--Josh Micah Marshall
Anonymous
March 9, 2005 6:38:02 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <slrnd2srsp.jji.br@panix5.panix.com>,
Ben Rosengart <br+rpdss@panix.com> wrote:
>On 8 Mar 2005 22:04:13 -0500, DoN. Nichols <dnichols@d-and-d.com> wrote:
>>
>> It would be simple enough to use a MD5 hash of a combination of
>> the image and the camera's model number and serial number -- plus a
>> private key hidden in the camera. This should suffice for a signature.
>> (Hmm ... toss in the date too -- so that can be verified as well --
>> compare the date stored in the image's info fields with that rolled into
>> the MD5 hash, so a photo taken later could not be substituted.)
>
>Make it SHA-256, in light of the recently discovered flaws in MD5
>and SHA-1.

O.K. I wasn't following that.

> And how about tossing in GPS info as well?

Probably not a bad idea, if the camera is equipped to record GPS
info into the image (something which would be useful in some fields --
including your spies. :-)


>
>> Of course, something like PGP (or some other
>> private-key/public-key cipher) would be better (more secure), but that
>> would require more processing power in the camera -- perhaps taking the
>> frame rate down to something like one frame per minute. :-)
>
>You weren't speaking of a public-key system when you referred to a
>"private key"?

Not in the first instance -- just as something unique to the
camera, and not predictable from the camera's serial number and model
number. Maybe a hash of the owner's birthdate, plus other bits of
information, or anything else, as long as it is not a known relationship
to anyone else.

Or even better -- a digitization of his/her right big toe
(finger?)print. :-)

>> O.K. On a 300 MHz Ultra-SPARC CPU, a md5 hash of a 1.5 MB JPEG
>> image takes:
>
>I think the expensive part is the public-key math -- which is still
>not so bad since you're only signing a hash, not the message itself.
>(Ok, I'm handwaving here, I'm not actually sure which is more costly.)

Actually -- the most expensive, I believe, is the generation of
the initial public-key/private-key pair -- at least based on the
initialization of PGP.

>> A PGP signature would take somewhat longer, and a full PGP
>> encryption of the entire file would take significantly longer
>
>There's also no real reason to do that.

Agreed. Anyone should be able to examine the image, and to use
it without needing to decrypt it. (Though your spy might like the
encrypted version. :-)

>> -- so it
>> depends on how much security you need -- and how much you are willing to
>> accept that the encrypted image may become unrecoverable from a single
>> bit error near the beginning. :-) I think that the PGP signature would
>> be the best, with a private key in the camera (or the flash card), and a
>> public key in the reader for verification.
>
>Agreed, though it could just as easily be x.509.

O.K. I was mentioning PGP as the one most easy to come by, and
most familiar to me. (That and GPG.)

>As my friend Thor pointed out to me when I was working on this,
>you can include the camera public key in the signed image, if you
>sign it with the vendor's private key. Then there's only one public
>key that everyone needs: the vendor's.

O.K. If the public key is in the encrypted signature, and not
in the unencrypted info.

>I have some very nice diagrams of all of this that I commissioned
>when I still thought I was going to apply for a patent. :-) Talk
>about your expensive mistakes.

Sorry about that. Better luck with your next project.

Enjoy,
DoN.

--
Email: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---
March 9, 2005 6:46:17 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

> A PGP signature would take somewhat longer, and a full PGP
>encryption of the entire file would take significantly longer -- so it
>depends on how much security you need -- and how much you are willing to
>accept that the encrypted image may become unrecoverable from a single
>bit error near the beginning. :-) I think that the PGP signature would
>be the best, with a private key in the camera (or the flash card), and a
>public key in the reader for verification. That way, it would not
>matter whether the reader was destroyed, as long as a record of the
>public key was available. And -- there is no real reason to keep the
>public key secret, so *anyone* could verify a copy of the image.
>
> Enjoy,
> DoN.

Don,

I have "played" with PGP since 2.6.2, so I at least know a little
about what you are writing about. However, if it gets to all this I
will go into the storage room and find my old Speed Graphic. It would
be cheaper and simpler. :) 

Also, I usually have an assistant along (for measurements ... and a
little extra firepower) and she would be available to testify as to
the photographs as well. It has not been necessary yet.

Marty ... who is (at this hour) leaning towards the XT due to the
lower cost primarily. I will probably shoot at 10mm wide open and
manual focus at just below infinity. With 10mm it all should fall into
dof, even wide open. Naturally I can bracket ISO and/or shutter
speeds. After a few tests I should know if I need a tripod or not. I
am pretty steady for an old geezer and I usually have a car or pole or
wall to use as a brace. I usually make three sets of 5x7s since I like
the jury to have a set in their hands rather than looking across the
room at larger prints (if they are awake). You cannot look at prints
and pass them along while you are asleep. And I believe there is
something personal about having them in their hands.

Thanks,
Marty
Anonymous
March 9, 2005 6:46:18 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <nrqs21tr6218qbsbatuh42mld3bf51j7b4@4ax.com>,
Marty <ehasz@ix.netcom.com> wrote:
>
>> A PGP signature would take somewhat longer, and a full PGP
>>encryption of the entire file would take significantly longer -- so it

[ ... ]

>Don,
>
>I have "played" with PGP since 2.6.2, so I at least know a little
>about what you are writing about. However, if it gets to all this I
>will go into the storage room and find my old Speed Graphic. It would
>be cheaper and simpler. :) 

Sorry -- I got carried away with the "how" even after the need
had been proven to be not present.

>Also, I usually have an assistant along (for measurements ... and a
>little extra firepower) and she would be available to testify as to
>the photographs as well. It has not been necessary yet.

Good enough.

>Marty ... who is (at this hour) leaning towards the XT due to the
>lower cost primarily. I will probably shoot at 10mm wide open and
>manual focus at just below infinity. With 10mm it all should fall into
>dof, even wide open.

Of course your effective focal length (as determined by your
coverage) will be 16mm, as contarasted with the 18mm for the Nikon with
its widest setting being 12mm. But presumably, this should be
sufficient.

[ ... ]

>wall to use as a brace. I usually make three sets of 5x7s since I like
>the jury to have a set in their hands rather than looking across the
>room at larger prints (if they are awake). You cannot look at prints
>and pass them along while you are asleep. And I believe there is
>something personal about having them in their hands.

Have you ever had problems with the jury being confused by the
perspective that you get with a really wide lens?

Good Luck,
DoN.

--
Email: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---
March 9, 2005 6:58:35 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Tue, 8 Mar 2005 22:22:35 -0500, "Walt Hanks"
<walthanks@comcast.net> wrote:

>>
>
>Let me guess, Charles between Penn Station and North Ave? <g>
>
>Let us know what you decide to get. You might consider renting both for a
>day or two to see how they feel for you. I think that Service Photo (my
>favorite shutter shack) rents both systems. Just don't get Abe started on
>the Nikon/Canon stuff though. You'll be there for hours.
>
>Walt
>

Hey Walt ... small world ain't it? I didn't know Service was still in
business. I used to go there in the late sixties or early seventies
when you were a kid. What do you shoot with? No jokes intended here.

PS You know Charles Street is too well lit. :) 
Anonymous
March 9, 2005 6:58:36 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

"Marty" <ehasz@ix.netcom.com> wrote in message
news:qpss21p12bn0lj857gncurnlj58t52tk67@4ax.com...
> On Tue, 8 Mar 2005 22:22:35 -0500, "Walt Hanks"
> <walthanks@comcast.net> wrote:
>
>>>
>>
>>Let me guess, Charles between Penn Station and North Ave? <g>
>>
>>Let us know what you decide to get. You might consider renting both for a
>>day or two to see how they feel for you. I think that Service Photo (my
>>favorite shutter shack) rents both systems. Just don't get Abe started on
>>the Nikon/Canon stuff though. You'll be there for hours.
>>
>>Walt
>>
>
> Hey Walt ... small world ain't it? I didn't know Service was still in
> business. I used to go there in the late sixties or early seventies
> when you were a kid. What do you shoot with? No jokes intended here.
>
> PS You know Charles Street is too well lit. :) 

Service Photo is over on Falls road now. I shoot a Nikon N-70. I recently
sold all of my old manual focus equipment and am watching and waiting to see
what develops between now and when I can afford to buy something before I
make a final decision on which digital system to buy into.

Walt
March 9, 2005 7:19:03 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Tue, 8 Mar 2005 23:09:11 -0500, "Walt Hanks"
<walthanks@comcast.net> wrote:

>Service Photo is over on Falls road now. I shoot a Nikon N-70. I recently
>sold all of my old manual focus equipment and am watching and waiting to see
>what develops between now and when I can afford to buy something before I
>make a final decision on which digital system to buy into.
>
>Walt
>

It used to be on Greenmount didn't it? About 3100 block?? That's when
I was rolling my own Tri-X and it cost about 1 cent per negative that
way. D-76 developer.
March 9, 2005 7:23:48 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

"Colin D" <ColinD@killspam.127.0.0.1> wrote in message
news:422D8336.DBD84073@killspam.127.0.0.1...
>
>
> Marty wrote:
> >
> > Finally I am going to switch from film totally. I am to either go
> > Canon or Nikon and totally based on this WA question. I will do 85% of
> > my work with the WA lens. My work is crime scenes. Mostly alleys and
> > interiors ... some at night. I prefer not using flash and rather use a
> > tripod when necessary.
> >
> > Which lens is better with regards to sharpness and lack of distortion?
> > Not having a big budget, it is going to be D70 or Rebel XT based
> > solely on this lens choice.
> >
> > Thank you all for any input.
> >
> > Marty
>
> I don't now whether you do this 'officially' for police or legal
> reasons, but if you will be in a position to rely on your shots as
> evidence in a court, you may be called on to prove the authenticity of
> your pictures. A negative is generally regarded as incontrovertible
> proof of authenticity, but the ease with which digital images can be
> tampered with generally means it is harder to prove the image as
> genuine.
>
> Canon is working on (may have it on the market now, as I haven't been
> following the progress) a system that will be proof of authenticity for
> a digital image, for the reasons outlined above. I am unaware of any
> move in that direction by Nikon, or any other maker of digital cameras.
>

20D has this security feature. If you are shooting professionally, I would
go with 20D or even 1D MkII, since you can claim it as a business cost.

> This may well dictate your choice of camera, and hence lens.
>
> Colin
Anonymous
March 9, 2005 7:57:12 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On 8 Mar 2005 22:54:52 -0500, DoN. Nichols <dnichols@d-and-d.com> wrote:
>
> Actually -- the most expensive, I believe, is the generation of
> the initial public-key/private-key pair -- at least based on the
> initialization of PGP.

Fortunately that doesn't have to be done in the camera.

> In article <slrnd2srsp.jji.br@panix5.panix.com>,
> Ben Rosengart <br+rpdss@panix.com> wrote:
>
>>As my friend Thor pointed out to me when I was working on this,
>>you can include the camera public key in the signed image, if you
>>sign it with the vendor's private key. Then there's only one public
>>key that everyone needs: the vendor's.
>
> O.K. If the public key is in the encrypted signature, and not
> in the unencrypted info.

No reason for the public key to be encrypted. It's public. It just
needs to be signed.

>>I have some very nice diagrams of all of this that I commissioned
>>when I still thought I was going to apply for a patent. :-) Talk
>>about your expensive mistakes.
>
> Sorry about that. Better luck with your next project.

Thanks. I can't really complain: I had fun, and maybe some day I'll
get to use what I learned about the patent system.

--
Ben Rosengart (212) 741-4400 x215
Sometimes it only makes sense to focus our attention on those
questions that are equal parts trivial and intriguing.
--Josh Micah Marshall
Anonymous
March 9, 2005 7:57:13 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <slrnd2t0h8.rs6.br@panix5.panix.com>,
Ben Rosengart <br+rpdss@panix.com> wrote:
>On 8 Mar 2005 22:54:52 -0500, DoN. Nichols <dnichols@d-and-d.com> wrote:
>>
>> Actually -- the most expensive, I believe, is the generation of
>> the initial public-key/private-key pair -- at least based on the
>> initialization of PGP.
>
>Fortunately that doesn't have to be done in the camera.

Amen!

>> In article <slrnd2srsp.jji.br@panix5.panix.com>,
>> Ben Rosengart <br+rpdss@panix.com> wrote:
>>
>>>As my friend Thor pointed out to me when I was working on this,
>>>you can include the camera public key in the signed image, if you
>>>sign it with the vendor's private key. Then there's only one public
>>>key that everyone needs: the vendor's.
>>
>> O.K. If the public key is in the encrypted signature, and not
>> in the unencrypted info.
>
>No reason for the public key to be encrypted. It's public. It just
>needs to be signed.

You're right. I was thinking private key for whatever reason,
instead of reading what you actually wrote.

>>>I have some very nice diagrams of all of this that I commissioned
>>>when I still thought I was going to apply for a patent. :-) Talk
>>>about your expensive mistakes.
>>
>> Sorry about that. Better luck with your next project.
>
>Thanks. I can't really complain: I had fun, and maybe some day I'll
>get to use what I learned about the patent system.

My experience with it came at no cost (and no gain) to me. I
was working for an Army R&D lab at the time, and they paid for the
patent processing, and provided the legal expertise. Of course, they
got the rights to use it for Government purposes, and only if there was
a private enterprise application would I get any possible royalties. Of
course, there weren't. :-)

Enjoy,
DoN.

--
Email: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---
March 9, 2005 11:37:13 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

2005-03-08, Ben Rosengart wrote:
> On Tue, 08 Mar 2005 23:49:26 +1300, Colin D <ColinD@killspam.127.0.0.1> wrote:
>>
>> Canon is working on (may have it on the market now, as I haven't been
>> following the progress) a system that will be proof of authenticity for
>> a digital image, for the reasons outlined above.
>
> It's out there; in its second version, even. The part is the DVK-E2.
> The press release says it works with the 1Ds and the 1D MkII. I'd
> guess it works with the 1Ds MkII as well. Somewhere on dpreview, it
> says that this thing works with the 20D, but I have a 20D and I
> don't believe that that's correct.
>
> http://www.dpreview.com/news/0401/04012903canondvke2.as...

So, how does it work? I cannot find any details.

> I was awfully chagrined when the DVK-E2's release was covered on
> Slashdot about a year ago, as I had been working for several months
> on a nearly identical invention. Canon and I even identified the

You and me both....

-peter
Anonymous
March 9, 2005 1:28:58 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

DoN. Nichols wrote:

>
>
>> And how about tossing in GPS info as well?
>
>
> Probably not a bad idea, if the camera is equipped to record GPS
> info into the image (something which would be useful in some fields --
> including your spies. :-)

There is at least one SLR that EXIF's GPS data into image file. I don't
remember which.

--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: there's no such thing as a FreeLunch.
Anonymous
March 9, 2005 1:51:27 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <slrnd2srsp.jji.br@panix5.panix.com>,
Ben Rosengart <br+rpdss@panix.com> wrote:
>I think the expensive part is the public-key math -- which is still
>not so bad since you're only signing a hash, not the message itself.
>(Ok, I'm handwaving here, I'm not actually sure which is more costly.)

On a low-end system (say Pentium-133) with slightly optimized C code,
computing a SHA-256 hash is about 1 Mbyte/s. Computing a 2048-bit RSA
signature takes about 5 seconds.

I don't know how fast the CPUs are that they put cameras.

--
That was it. Done. The faulty Monk was turned out into the desert where it
could believe what it liked, including the idea that it bad been done by.
It was allowed to keep its horse, since horses where so cheap to make.
-- Douglas Adams in Dirk Gently's Holistic Detective Agency
Anonymous
March 9, 2005 3:23:49 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <2PadnXVIlpYe-rPfRVn-ig@comcast.com>, walthanks@comcast.net
says...
> > It might exist someday. Wait until some circumstance arises where a
> > defense lawyer has an opportunity to call the photo into question
>
> It would take an incredibly big case and clear alteration of evidence to get
> long-standing legal precedent set aside.

I'm sure of it. But things have a funny way of coming about.

What if a journalist snapped photos of a crime in progress with a
digital camera and those photos were used as evidence, much as closed-
circuit video footage is? Would someone dare accuse the photographer of
digital manipulation, and would the judge be stupid enough to believe
him?
Anonymous
March 9, 2005 3:23:50 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

"Brian C. Baird" <nospam@please.no> wrote in message
news:MPG.1c98b4e4182f5ff898a7bc@news.verizon.net...
> In article <2PadnXVIlpYe-rPfRVn-ig@comcast.com>, walthanks@comcast.net
> says...
>> > It might exist someday. Wait until some circumstance arises where a
>> > defense lawyer has an opportunity to call the photo into question
>>
>> It would take an incredibly big case and clear alteration of evidence to
>> get
>> long-standing legal precedent set aside.
>
> I'm sure of it. But things have a funny way of coming about.
>
> What if a journalist snapped photos of a crime in progress with a
> digital camera and those photos were used as evidence, much as closed-
> circuit video footage is? Would someone dare accuse the photographer of
> digital manipulation, and would the judge be stupid enough to believe
> him?

Accuse - certainly. And if the images were the only evidence the
prosecution had, the accusation might carry some weight. But the images are
never the only evidence. This issue has to be considered within the global
context of what occurs in a trial.

And if it ever happens that a conviction is lost because of it, then the
technology will be needed. But by then, everything discussed here today
will be technologically "old news."

Walt
Anonymous
March 9, 2005 4:02:34 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <vZKdnRNefK5NbLPfRVn-1w@comcast.com>, walthanks@comcast.net
says...
> > circuit video footage is? Would someone dare accuse the photographer of
> > digital manipulation, and would the judge be stupid enough to believe
> > him?
>
> Accuse - certainly. And if the images were the only evidence the
> prosecution had, the accusation might carry some weight. But the images are
> never the only evidence. This issue has to be considered within the global
> context of what occurs in a trial.

You're correct in the fact the prosecution could never go to trial with
photos alone - but they could go to trial with their case heavily
dependant on photographs of the crime in progress.

> And if it ever happens that a conviction is lost because of it, then the
> technology will be needed. But by then, everything discussed here today
> will be technologically "old news."
>
> Walt

Well, a conviction was lost because a glove "didn't fit". Well, that,
really lousy police work and a star-struck judge.

Canon seems to be thinking a little too far ahead on this issue. To my
knowledge, no one is using/has bought those data verification kits. The
one market they may of had, crime scene/police photographers, apparently
doesn't need them!
March 9, 2005 4:09:37 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

2005-03-09, Brian C Baird wrote:
>[...]
> Canon seems to be thinking a little too far ahead on this issue. To my
> knowledge, no one is using/has bought those data verification kits. The
> one market they may of had, crime scene/police photographers, apparently
> doesn't need them!

I find that hard to believe. Even outside crime scene/police work the need
to be able to ,,sign'' digital documents (be it photo's or something else)
is obvious, and people have been doing it for a long time (way before 1999
so how this patent came about someone mentioned in another posting...).

Well, if it is true, it is time to get worried about the police force...

-peter
Anonymous
March 9, 2005 5:20:42 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

If you prefer high ISO and low noise, then you're going to have to go
the Canon route.
Anonymous
March 9, 2005 6:59:13 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On 09 Mar 2005 13:09:37 GMT, Peter <durians.nomail@gmx.net> wrote:
>
> I find that hard to believe. Even outside crime scene/police work the need
> to be able to ,,sign'' digital documents (be it photo's or something else)
> is obvious, and people have been doing it for a long time (way before 1999
> so how this patent came about someone mentioned in another posting...).

The patent isn't on signing data, it's on a camera that signs its
output. This is cool because as long as the camera is relatively
tamperproof, the photographer need not be trusted! (You can see
why spying and insurance came to mind as target markets.)

--
Ben Rosengart (212) 741-4400 x215
Sometimes it only makes sense to focus our attention on those
questions that are equal parts trivial and intriguing.
--Josh Micah Marshall
Anonymous
March 9, 2005 8:01:11 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Walt Hanks wrote:

> Accuse - certainly. And if the images were the only evidence the
> prosecution had, the accusation might carry some weight. But the
images are
> never the only evidence. This issue has to be considered within the
global
> context of what occurs in a trial.

You are without a clue.

If someone submits evidence that is later shown to be a forgery or
similar on the part of the submitter, it casts a major pall on the rest
of the case. So severe a dread, that the likelihood of dismissal,
mis-trial or at least suppression of other evidence (and the
concommitant loss of a prosecution/defense) is very high, if not an
absolute certainty. Indeed, it can effect other, unrelated, cases.

This isn't idle speculation: it has happened.

www.google.com: rampart los angeles police
www.google.com: toronto drug squad scandal
www.google.com: FBI lab scandal

etc etc etc

It strikes me that anything that can preclude abuse to a very high
degree of probability, is fairly easy to implement, at almost no user
cost, is a Very Good Thing and to be Highly Desired.

> And if it ever happens that a conviction is lost because of it, then
the
> technology will be needed.

A character of intelligence is to foresee predictable consequences of
one's actions. Only an idiot would build a house on a river flood
plain, asserting that "if the house is lost only then the technology
for a better house construction or location be needed".

Why adopt a "new" form of evidence that is open to trivial abuse? Why
accept the mere word of the photographer that the image is a "faithful"
rendition of the scene, when, in addition, there could be a
proof-process that stretches from the court room, though whatever
information processing systems, all the way back to who was touching
the camera at the time the shutter was tripped? (c.f. chain of
evidence rules.)

Basically, why lay the groundwork for a future scandal?
Anonymous
March 9, 2005 9:46:57 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <slrnd2u7ah.ld1.br@panix5.panix.com>,
Ben Rosengart <br+rpdss@panix.com> wrote:
>On 09 Mar 2005 13:09:37 GMT, Peter <durians.nomail@gmx.net> wrote:
>>
>> I find that hard to believe. Even outside crime scene/police work the need
>> to be able to ,,sign'' digital documents (be it photo's or something else)
>> is obvious, and people have been doing it for a long time (way before 1999
>> so how this patent came about someone mentioned in another posting...).
>
>The patent isn't on signing data, it's on a camera that signs its
>output. This is cool because as long as the camera is relatively
>tamperproof, the photographer need not be trusted! (You can see
>why spying and insurance came to mind as target markets.)

I don't want to know how you can patent something a trivial as that.

(If the camera has to sign it, there is a trivial way around it, just
have to camera encrypt the data and have some other device decrypt and
sign the data. Using public keys this is relatively easy to secure, doesn't
require anything special in the camera (other than a public key) and
provides confidentiality when images are transmitted wireless.).


--
That was it. Done. The faulty Monk was turned out into the desert where it
could believe what it liked, including the idea that it bad been done by.
It was allowed to keep its horse, since horses where so cheap to make.
-- Douglas Adams in Dirk Gently's Holistic Detective Agency
Anonymous
March 9, 2005 9:46:58 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Wed, 9 Mar 2005 18:46:57 +0100, Philip Homburg
<philip@pch.home.cs.vu.nl> wrote:
> In article <slrnd2u7ah.ld1.br@panix5.panix.com>,
> Ben Rosengart <br+rpdss@panix.com> wrote:
>>
>>The patent isn't on signing data, it's on a camera that signs its
>>output. This is cool because as long as the camera is relatively
>>tamperproof, the photographer need not be trusted! (You can see
>>why spying and insurance came to mind as target markets.)
>
> I don't want to know how you can patent something a trivial as that.

It fits all the criteria of a patentable concept.

Lots of things are "trivial" once someone else has thought of it and
told you about it.

> (If the camera has to sign it, there is a trivial way around it, just
> have to camera encrypt the data and have some other device decrypt and
> sign the data. Using public keys this is relatively easy to secure, doesn't
> require anything special in the camera (other than a public key) and
> provides confidentiality when images are transmitted wireless.).

No. (I guess it's not so "trivial" after all.)

--
Ben Rosengart (212) 741-4400 x215
Sometimes it only makes sense to focus our attention on those
questions that are equal parts trivial and intriguing.
--Josh Micah Marshall
Anonymous
March 9, 2005 9:46:58 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Philip Homburg wrote:

> (If the camera has to sign it, there is a trivial way around it, just
> have to camera encrypt the data and have some other device decrypt and
> sign the data. Using public keys this is relatively easy to secure, doesn't
> require anything special in the camera (other than a public key) and
> provides confidentiality when images are transmitted wireless.).

I'm not sure why it has to be that involved. Each individual camera
could have a key associated with its serial number. Sign the image with
the private key and anyone can D/L the public key (from the OEM website)
and verify it.

Cheers,
Alan

--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: there's no such thing as a FreeLunch.
Anonymous
March 9, 2005 9:48:02 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <d0n4ng$t4i$1@inews.gazeta.pl>,
Alan Browne <alan.browne@freelunchVideotron.ca> wrote:
>DoN. Nichols wrote:
>>> And how about tossing in GPS info as well?
>>
>> Probably not a bad idea, if the camera is equipped to record GPS
>> info into the image (something which would be useful in some fields --
>> including your spies. :-)
>
>There is at least one SLR that EXIF's GPS data into image file. I don't
>remember which.

Without a built-in GPS, how can you trust the GPS data?


--
That was it. Done. The faulty Monk was turned out into the desert where it
could believe what it liked, including the idea that it bad been done by.
It was allowed to keep its horse, since horses where so cheap to make.
-- Douglas Adams in Dirk Gently's Holistic Detective Agency
!