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old slides and scanning

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Anonymous
March 16, 2005 3:46:10 PM

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

HOW TO GET QUALITY SCANS THAT RESPOND TO COLOR CORRECTION

If you are using an epson scanner, they come with a toned down version
of Adobe Photoshop. In it is a good medium quality color correction.
Scan your slides at 2,400 DPI. You do not need anything higher because
you are then funneling down beyond the resolution on the slide itself.
I have scanned several thousand slides since 2001 and I can tell you
there is no difference between 48bit and 24 bit. The only difference
you might see between these two is from a native source such as a
digital camera. The slides do not have enough info in them to utilize
the potential data beyond 24 bit 2,400 DPI. At 2,400 DPI the color
correction and auto level adj will work best. Try it at home, do a
1,200 DPI scan and a 2,400 DPI scan of the same image, put them side by
side and apply color correction tothem both, save them both, close all
the files, reopen them and compare side by side. You may have to ZOOM
way in and look at pixelation side by side. Adobe has histograms based
on scientifically recorded probability as to how colors change hue in
the natural world. The more data you have present the better chance it
can adjust your old faded colors with a better result.
Read more at my web, I am a professional photographer and videographer
and video editor with a articles folder.
http://www.dvdhomevideoeditor.com/product_4_SlidesPhoto...
I have been attacked by competitors lately so if it does not come up,
just click open again.
Any problems, seriously, drop me a line using email from my web. I
repsond to all inquiries, period.
Ted
Master Editor

More about : slides scanning

Anonymous
March 16, 2005 6:17:48 PM

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

Is this in regard to web-display only??? If so, my tirade below may be
a little harsh, but you haven't made it clear..


> Scan your slides at 2,400 DPI. You do not need anything higher
because
> you are then funneling down beyond the resolution on the slide itself

There is *plenty* of detail beyond 2400 dpi. Ever heard of the Minolta
5400 dpi CONSUMER film scanners? Go look up the resolution of a drum
scanner...

> there is no difference between 48bit and 24 bit

What???? If you truly believe that, you have never done much
post-processing, or used a histogram.... I stopped reading.

If you are going to post stuff like this, explain what you are
referring to. If this is about general film scanning, then you are
*way* off the mark, and need to go back and do some serious homework.
Anonymous
March 16, 2005 9:57:20 PM

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

I agree totally, rafe, i just wanted to point out the (potentially
fatal) flaws in the OP. This guy's website suggests he is offering
these services to ARCHIVE people's images. If I wanted to archive my
collection of slides, there is no way I would let it be done on
anything less than a 2700 dpi flim scanner. In reality, I would want
it done on a 4000 dpi scanner, and yes, I've used both types of scanner
and seen how they differ. So unless you are just archiving images
taken on a $50 point and shoot, or they are only for web-viewing, I
think 2400 is selling most images short....(and especially when he is
referring to a flatbed scanner that probably only achieves about
1800-2000 ppi anyway)...

And yes, I agree you probably won't spot the difference between a 24
and 48 bit image *if* it is just the initial scan... but if you are
going to be playing with levels, and doing a fair amount of
post-processing, working with 48 bits has quite noticable advantages.
In particular, posterisation will become an issue with some operations,
and you can end up with something looking like a GIF file.. Once
bitten, twice shy!

If all this was about was creating a DVD for family viewing on the
telly... maybe. But if you were planning to process and print those
images to say 12x8 with minimal loss of quality....
Related resources
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Anonymous
March 16, 2005 10:05:04 PM

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

By the way, it probably needs to be said that the only reason the OP
can't see much difference between 1200 and 2400 is that his scanner is
only capable of about 1800 anyway - so that is more of a commentary on
the scanner!
Anonymous
March 16, 2005 10:09:38 PM

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

chrlz@go.com wrote:
> Is this in regard to web-display only??? If so, my tirade below may be
> a little harsh, but you haven't made it clear..
>
>
>
>>Scan your slides at 2,400 DPI. You do not need anything higher
> because
>>you are then funneling down beyond the resolution on the slide itself
>
>
> There is *plenty* of detail beyond 2400 dpi. Ever heard of the Minolta
> 5400 dpi CONSUMER film scanners? Go look up the resolution of a drum
> scanner...


Sure, you can find drum scanners rated up to 12000 dpi.
But I've never seen a real photo, from any camera, with
anywhere near that level of detail. In fact from what
I've seen, 4000 dpi will capture 95% of the detail in any
image I've seen, from any camera/lens/film combo.
2700 dpi might hold 85-90%. Rough figures, of course.

Check out the scan samples here:

<http://www.terrapinphoto.com/jmdavis/&gt;


>>there is no difference between 48bit and 24 bit
>
>
> What???? If you truly believe that, you have never done much
> post-processing, or used a histogram.... I stopped reading.


Again, if you scan carefully and don't yank too hard
on the curves tool in Photoshop, a 24 bit scan will
suffice 95% of the time. I wouldn't say "no difference."
I would say the difference is highly overrated and over-
stated. If you're going to judge an image by the gaps
in its histogram, I'd say it's you who's off the mark.

Those gaps may be fatal to some images, and utterly
innocuous to others. Images composed of lots of fine
detail need minimal bit depth. Images with large areas
of near-monochrome tones or subtle gradients need more
bit depth. You can test this with Image->Adjust->Posterize
in Photoshop. I'm sometimes surprised by how *few* levels
are necessary for proper rendering of images.


> If you are going to post stuff like this, explain what you are
> referring to. If this is about general film scanning, then you are
> *way* off the mark, and need to go back and do some serious homework.

I know a thing or two about film scanning. Let's chat.



rafe b.
http://www.terrapinphoto.com
Anonymous
March 16, 2005 10:09:39 PM

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

rafeb wrote:
>
>
> chrlz@go.com wrote:
>> Is this in regard to web-display only??? If so, my tirade below may be
>> a little harsh, but you haven't made it clear..

>>> Scan your slides at 2,400 DPI. You do not need anything higher
>> because
>>> you are then funneling down beyond the resolution on the slide itself

>> There is *plenty* of detail beyond 2400 dpi. Ever heard of the Minolta
>> 5400 dpi CONSUMER film scanners? Go look up the resolution of a drum
>> scanner...

> Sure, you can find drum scanners rated up to 12000 dpi.
> But I've never seen a real photo, from any camera, with
> anywhere near that level of detail. In fact from what
> I've seen, 4000 dpi will capture 95% of the detail in any
> image I've seen, from any camera/lens/film combo.
> 2700 dpi might hold 85-90%. Rough figures, of course.

The OP said there was little difference between 2400 and 1200
ppi scans. Depending on the film and whether or not
you used a tripod, that statement is way off. I agree
with chrlz.
>
> Check out the scan samples here:
> <http://www.terrapinphoto.com/jmdavis/&gt;

Do these samples not show that 4000 ppi drum scans is getting
most of the info, and the comparison of ~2400 versus 4000 ppi
is quite a big difference? Then consider the OP says not much
difference between 2400 and 1200?

See:
http://www.clarkvision.com/imagedetail/scandetail.html#...
where 35mm drum scanned velvia is compared at 2700, 4000, 6000,
and 8000 dpi, along with consumer scanners at 2400 to 4000 dpi.
Note the detail in "area A and area B. There is a big difference
between 4000 dpi and 6000 dpi drum scans, but not much
between 6000 and 8000. There is a huge difference
from 2400 to 4000 dpi, and even more to 1200 dpi.
The OP's position is simply not supported by facts.

Regarding 8 versus 16-bit's per pixel, I have found less need for
split density filters even on Velvia slide film as I can coax out
normally unprintable detail in skies and clouds if I do
16-bit scans. For example:
http://www.clarkvision.com/galleries/gallery.landscape-...
this image was done with a split density filter but the clouds
would print white in a standard enlarger print. The 16-bit scan
allowed me to get the detail in the slide. I am a total convert
to 16-bit processing. My first step in working on an 8-bit/pixel
jpeg from my digital camera is convert to 16-bit. That way I minimize
posterization and can get more out if the image.

Roger
Anonymous
March 17, 2005 1:11:34 AM

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

On Wed, 16 Mar 2005 18:40:24 -0700, "Roger N. Clark (change username
to rnclark)" <username@qwest.net> wrote:


>Do these samples not show that 4000 ppi drum scans is getting
>most of the info, and the comparison of ~2400 versus 4000 ppi
>is quite a big difference? Then consider the OP says not much
>difference between 2400 and 1200?


I guess I'd take a stand somewhere between chrlz and the OP.
One exaggerates toward the low end, the other towards the
high end.

I've only seen a handful of real images, from any scanner,
that show significant detail beyond 4000 dpi. And I say
this after a brief period of owning a fine old 5000 dpi
drum scanner.

Even so, I believe you're now scanning your 4x5 with
an Epson 4870? And surely you're not going to claim
that its real resolution is anywhere near 4800 dpi?

Plus there's something very strange about your scan-
resolution comparisons. Where's the grain? Even the
best slide films will have lots of grain showing
at these resolutions. (The 2nd, 3rd and 4th 35mm
images in scanres-samp2.jpg)


>I am a total convert to 16-bit processing. My first
>step in working on an 8-bit/pixel jpeg from my digital
>camera is convert to 16-bit. That way I minimize
>posterization and can get more out if the image.


I'm not quite convinced. And neither is Dan Margulis.
But with memory and drive space as cheap as they are,
one can have it both ways. I confess to doing more
of my scanning at 16 bit these days, though I'm not
at all convinced of the need or benefit.

We agree, I hope, that most scanners don't deliver
much more than 11 or 12 bits (at best) of real data,
regardless of their claimed bit depth. Anything
beyond that is usually noise.

16-bit processing simply allows you to defer your
major color moves further down the image-processing
chain before irretrievable loss of tonality occurs.

If you scan carefully -- ie., use all the range
available in all color channels -- the benefit
is minimal. Unless of course you plan to do
really radical color moves in Photoshop.

If you use half the range, you are in effect
throwing away one bit worth of image data.

Given a perfect output device, how many folks
could distinguish every step of a 256-step
grayscale wedge?

If you went to 128 steps, how much more distinct
would the steps be?

Now add noise to the picture (literally, since
most images have noise in abundance) and the
edges between the steps gets even hazier.

I think if there weren't a histogram for people
to look at, 16 bit processing wouldn't be anywhere
near as popular is it is. Somewhere along the
line someone decided that gapped histograms
were a Very Bad Thing... regardless of whether
there's an observable effect of that, on-screen
or in print.

Again, if the image in question involves subtle
gradients and large "near-monochrome" areas, those
extra bits might come in handy. But I've seen few
examples of this in practice.


rafe b.
http://www.terrapinphoto.com
Anonymous
March 17, 2005 1:11:35 AM

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

rafe bustin wrote:

> Even so, I believe you're now scanning your 4x5 with
> an Epson 4870? And surely you're not going to claim
> that its real resolution is anywhere near 4800 dpi?

That is correct. I'm scanning my 4x5 velvia at 3200 dpi.
The scanner resolution is probably about that. The scans
are a little softer than then drum scans I have had done.
The problem with the drum scanner I use (Linotype-Hell; I need
to get exact model number) is that while it does
up to 11,0000 dpi and did 16 bits/pixel output,
the files written had to be 8-bit. I need to see if that
has changed in the last year. Anyway, what I found with the
epson is that while it was a little less spatial resolution
than the drum scan, the 16-bit output made better images (!!)
because the intensity detail was so much better.
>
> Plus there's something very strange about your scan-
> resolution comparisons. Where's the grain? Even the
> best slide films will have lots of grain showing
> at these resolutions. (The 2nd, 3rd and 4th 35mm
> images in scanres-samp2.jpg)

There is lots of grain in the images. Probably the best example
is the image at:
http://www.clarkvision.com/imagedetail/scandetail.html#...
See the image in this section, just above results/conclusions.
The image labeled "4x5 original 1.03x" shows the grain well.
Remember these images are fujichrome velvia, which shows much
less grain in scanned images than provia 100 which is what I see
most people use in scan comparisons.

> I'm not quite convinced. And neither is Dan Margulis.
> But with memory and drive space as cheap as they are,
> one can have it both ways. I confess to doing more
> of my scanning at 16 bit these days, though I'm not
> at all convinced of the need or benefit.

I also use a program called ImagesPlus which works in true
16-bit math as opposed to Photoshop's 15-bit. I'm seeing
posterization in Canon 1D mark II images processed in photoshop
in "16-bit" that I don't see in ImagesPlus.
For examples of an intensity profile of 8-bit versus 16-bit,
see Figure 9a,b,c,d at:
http://clarkvision.com/imagedetail/dynamicrange2

> We agree, I hope, that most scanners don't deliver
> much more than 11 or 12 bits (at best) of real data,
> regardless of their claimed bit depth. Anything
> beyond that is usually noise.

I agree. Most have 12-bit A-to-Ds anyway, or are
photon noise limited. But even with 12-bit DSLR data,
I see artifacts from processing in photoshop's 15-bit math.
I guess I need to put together some web pages showing
that effect. I'll add it to my list.

> If you scan carefully -- ie., use all the range
> available in all color channels -- the benefit
> is minimal. Unless of course you plan to do
> really radical color moves in Photoshop.

I agree, except when you need to compress dynamic
range, like bring detail out of clouds, it can't be done
in 8-bit (and I'm not talking color shifting).
Similarly when you want to bring detail
out of the shadows. 16-bit scans give you a better
chance of getting the detail, just like RAW files
on a digital camera give you more detail.

> Given a perfect output device, how many folks
> could distinguish every step of a 256-step
> grayscale wedge?

This is irrelevant. The whole point of image processing
is to bring the dynamic range into what can be output
into a medium for human viewing. It is a matter of
capturing the huge scene dynamic range, which is often
over 10, 11, or more stops, and compressing it for
viewing. Often the output medium is the limiting step,
not the human eye.

> I think if there weren't a histogram for people
> to look at, 16 bit processing wouldn't be anywhere
> near as popular is it is. Somewhere along the
> line someone decided that gapped histograms
> were a Very Bad Thing... regardless of whether
> there's an observable effect of that, on-screen
> or in print.

I strongly disagree. I've been doing image processing
for about 30 years. Sometimes I'm working with
data with a signal-to-noise tens of thousands and dynamic
ranges of millions (scientific applications). The ability
to capture a scene and bring out detail that could be seen
with the eye is pretty amazing--things that could not be done
with a traditional enlarger without special masks and
extreme skill. And that goes for film and 16-bit scans as
well as digital cameras and RAW files.
>
> Again, if the image in question involves subtle
> gradients and large "near-monochrome" areas, those
> extra bits might come in handy. But I've seen few
> examples of this in practice.

Perhaps it depends on what images you like to do.
I would say every landscape photo that includes the sky
and clouds qualifies.

Roger
Anonymous
March 17, 2005 4:24:58 AM

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

On Wed, 16 Mar 2005 21:40:01 -0700, "Roger N. Clark (change username
to rnclark)" <username@qwest.net> wrote:


>I strongly disagree. I've been doing image processing
>for about 30 years. Sometimes I'm working with
>data with a signal-to-noise tens of thousands and dynamic
>ranges of millions (scientific applications). The ability
>to capture a scene and bring out detail that could be seen
>with the eye is pretty amazing--things that could not be done
>with a traditional enlarger without special masks and
>extreme skill. And that goes for film and 16-bit scans as
>well as digital cameras and RAW files.


So it goes. This topic's been beat to death on
this and other fora for years, and even the
experts disagree. I respect and admire your
work and articles in this topic, but I think
there's still room for debate.

I don't usually resort to math in my approach to
"digital darkroom" but I know what works and what
doesn't. Posterization, even in clear blue skies,
is not an issue with my files or prints. Pure
luck? I doubt it. See if you can spot posterization
on any images on my website or the scan snippets
site. Clear blue sky? How about the 2nd "Perfect
Scan" near the top of the scan-snippets site?

On "my" side of the argument is a very clever fellow
named Dan Margulis, whom you may have heard of. In
fact you'll see a thread of this same discussion
somewhere on Dan's web site. A fellow named
Jeff Schewe is his main opponent in that debate.

I'm not about to discourage anyone from using 16
bit image files, but I've heard lots of ridiculous
claims for the benefits of doing so. For digicams
I certainly encourage the use of RAW files, but
that's a slightly different issue.

As for image resolution... again, I'm eager to
receive and post full-res scan samples -- any
film, any lens, any camera -- that can beat
the scans already posted. I really am
interested in the question, "Just how much
detail can be extracted from 0.25" x 0.25"
of film." Only real photos please, not
test targets. If you've got 6000 dpi scans,
I'll be happy to post a 1500 x 1500 pixel,
full-res snippet, cherry-picked for the
sharpest detail you can find, and JPG'd at
best quality/minimimum compression. Please
send a small "overview" JPG of the frame
from which the snippet is derived.


rafe b.
scan snippets:
http://www.terrapinphoto.com/jmdavis
Anonymous
March 17, 2005 1:50:14 PM

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

rafe bustin <rafeb@speakeasy.net> wrote:
> On Wed, 16 Mar 2005 18:40:24 -0700, "Roger N. Clark (change username
> to rnclark)" <username@qwest.net> wrote:

>>I am a total convert to 16-bit processing. My first
>>step in working on an 8-bit/pixel jpeg from my digital
>>camera is convert to 16-bit. That way I minimize
>>posterization and can get more out if the image.

> I'm not quite convinced.

It depends on your working space. 8 bits might be enough for sRGB,
but if you're working in a wide gamut space -- and that is a good idea
when you're scanning transparenices -- then 16 bits is a Good Thing.

Andrew.
Anonymous
March 17, 2005 2:16:00 PM

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

In article <113io769grbni36@news.supernews.com>,
<andrew29@littlepinkcloud.invalid> wrote:
>rafe bustin <rafeb@speakeasy.net> wrote:
>> On Wed, 16 Mar 2005 18:40:24 -0700, "Roger N. Clark (change username
>> to rnclark)" <username@qwest.net> wrote:
>
>>>I am a total convert to 16-bit processing. My first
>>>step in working on an 8-bit/pixel jpeg from my digital
>>>camera is convert to 16-bit. That way I minimize
>>>posterization and can get more out if the image.
>
>> I'm not quite convinced.
>
>It depends on your working space. 8 bits might be enough for sRGB,
>but if you're working in a wide gamut space -- and that is a good idea
>when you're scanning transparenices -- then 16 bits is a Good Thing.

Indeed. If the bits that make up a pixel value can represent lots of
different colours, then it stands to reason that they can represent fewer
sahdes of those colours - something has to give. 8 bit per channel wide
gamut images would seem to be at a greater risk of posterisation than
narrower gamut images.

This implies that when converting to 8 bits, sRGB for web use, one should
convert to sRGB *first*, then convert to 8 bits, and not th eother way
around.
Anonymous
March 17, 2005 8:17:28 PM

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

<chrlz@go.com> wrote in message
news:1111028704.351594.201390@l41g2000cwc.googlegroups.com...
> By the way, it probably needs to be said that the only reason the OP
> can't see much difference between 1200 and 2400 is that his scanner is
> only capable of about 1800 anyway - so that is more of a commentary on
> the scanner!
>

OK now that all of us have read (and tried to understand) the arguments can
someone please advise which flatbed to buy?
I have about 4000 colour slides and lots of black and white family photos
going back to the early 1940s whioch I would like to digitise for the whole
family. We are not wealthy and were wondering whether an Epson of about
2800dpi is enough or 3600 dpi or if in fact we need to spend $900 for one
with 4000 or even 4800 dpi? As you are aware the price does rocket upwards
the higher the resolution.

Thanks in advance.

Gerrit - Oz
Anonymous
March 17, 2005 8:17:29 PM

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

On Thu, 17 Mar 2005 17:17:28 +0800, "Gerrit 't Hart" <gthart@sad.au>
wrote:

>
><chrlz@go.com> wrote in message
>news:1111028704.351594.201390@l41g2000cwc.googlegroups.com...
>> By the way, it probably needs to be said that the only reason the OP
>> can't see much difference between 1200 and 2400 is that his scanner is
>> only capable of about 1800 anyway - so that is more of a commentary on
>> the scanner!
>>
>
>OK now that all of us have read (and tried to understand) the arguments can
>someone please advise which flatbed to buy?
>I have about 4000 colour slides and lots of black and white family photos
>going back to the early 1940s whioch I would like to digitise for the whole
>family. We are not wealthy and were wondering whether an Epson of about
>2800dpi is enough or 3600 dpi or if in fact we need to spend $900 for one
>with 4000 or even 4800 dpi? As you are aware the price does rocket upwards
>the higher the resolution.


Cheap good film scanner?

Plustek OpticFilm 7200, $189 at TigerDirect.

NOT from personal experience. Google it and
decide for yourself.


rafe b.
http://www.terrapinphoto.com
Anonymous
March 17, 2005 9:34:36 PM

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

"Gerrit 't Hart" <gthart@sad.au> wrote:
>
> OK now that all of us have read (and tried to understand) the arguments
can
> someone please advise which flatbed to buy?

Epson 4870 (under US$500) or Epson 4990 (US$600). (Prices are just guesses.)

> I have about 4000 colour slides and lots of black and white family photos
> going back to the early 1940s whioch I would like to digitise for the
whole
> family. We are not wealthy and were wondering whether an Epson of about
> 2800dpi is enough or 3600 dpi or if in fact we need to spend $900 for one
> with 4000 or even 4800 dpi? As you are aware the price does rocket upwards
> the higher the resolution.

Both these provide digital ICE, which automagically hides dust and scratches
when scanning color slides. Not having ICE is not nice. The 4990 has a
larger transparency adapter, so can scan more slides at the same time and
might be worth the extra money in speeding up the process.

The 4800 dpi claimed for these is a tad bogus. You can scan at 2400 dpi with
them and get nearly the same results (but better results than with "2400
dpi" scanners).

David J. Littleboy
Tokyo, Japan
Anonymous
March 17, 2005 11:03:05 PM

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

rafe bustin wrote:
> On Wed, 16 Mar 2005 21:40:01 -0700, "Roger N. Clark (change username
> to rnclark)" <username@qwest.net> wrote:
>
>
>
>>I strongly disagree. I've been doing image processing
>>for about 30 years. Sometimes I'm working with
>>data with a signal-to-noise tens of thousands and dynamic
>>ranges of millions (scientific applications). The ability
>>to capture a scene and bring out detail that could be seen
>>with the eye is pretty amazing--things that could not be done
>>with a traditional enlarger without special masks and
>>extreme skill. And that goes for film and 16-bit scans as
>>well as digital cameras and RAW files.
>
>
>
> So it goes. This topic's been beat to death on
> this and other fora for years, and even the
> experts disagree. I respect and admire your
> work and articles in this topic, but I think
> there's still room for debate.
>
> I don't usually resort to math in my approach to
> "digital darkroom" but I know what works and what
> doesn't. Posterization, even in clear blue skies,
> is not an issue with my files or prints. Pure
> luck? I doubt it. See if you can spot posterization
> on any images on my website or the scan snippets
> site. Clear blue sky? How about the 2nd "Perfect
> Scan" near the top of the scan-snippets site?

Blue sky is not so much an issue as are clouds. Clouds give
a scene character, and our eyes+brains are see that detail.
If it is washed out, it is like seeing a person's face erased
so you can't see their eyes, nose or mouth.

Here are some images from your site that I think need work, and
if these are film scans, might be improved with a 16-bit scan:

Bright cloud left center has little detail,
and rocks are black with no detail, image needs
shadow and highlight work:
http://www.terrapinphoto.com/oregon_bird_on_beach3.html
Scan this one with 8-bits and 16-bits/channel and see how much
shadow and highlight detail you can bring out in each.

Cloud highlights blown:
http://www.terrapinphoto.com/chengs_tree.html
http://www.terrapinphoto.com/marcydam2.html
http://www.terrapinphoto.com/mt_dix_grass.html
http://www.terrapinphoto.com/chim_pond_sunset_reflectio...
http://www.terrapinphoto.com/bridlepath_leaves_solarize...
http://www.terrapinphoto.com/old_lobster_trap.html
http://www.terrapinphoto.com/morocco_cityscape.html
http://www.terrapinphoto.com/duomo_from_uffizi.html
http://www.terrapinphoto.com/log_fence_near_wayah_bald....
http://www.terrapinphoto.com/kinsman_cairn2.html
http://www.terrapinphoto.com/nahmakanta_lake.html
http://www.terrapinphoto.com/cadillac_flowers.html
http://www.terrapinphoto.com/acadia.html
http://www.terrapinphoto.com/acadia_sunset2.html
http://www.terrapinphoto.com/tide_pool.html
http://www.terrapinphoto.com/red_cliff.html

I believe the above photos could be improved with a
16-bit scan. I'm not commenting on the image quality.
You have many nice photos. But in my opinion, blown
highlights on many.

I can point to images on my site that could use improvements too.
Sometime I'll go back and do better.
Example, here is a poor one (8-bit scan 4x5, poor processing;
not sure how much better processing will help):
http://www.clarkvision.com/galleries/gallery.san-juan-m...

This one is better (8-bit scan, 35mm):
http://www.clarkvision.com/galleries/gallery.san-juan-m...

Better yet in my opinion (16-bit scan 4x5):
http://www.clarkvision.com/galleries/gallery.san-juan-m...


Roger
http://www.clarkvision.com
Anonymous
March 18, 2005 2:37:49 AM

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

On Thu, 17 Mar 2005 20:03:05 -0700, "Roger N. Clark (change username
to rnclark)" <username@qwest.net> wrote:


>Cloud highlights blown:
>http://www.terrapinphoto.com/chengs_tree.html
>http://www.terrapinphoto.com/marcydam2.html
>http://www.terrapinphoto.com/mt_dix_grass.html
>http://www.terrapinphoto.com/chim_pond_sunset_reflectio...
>http://www.terrapinphoto.com/bridlepath_leaves_solarize...
>http://www.terrapinphoto.com/old_lobster_trap.html
>http://www.terrapinphoto.com/morocco_cityscape.html
>http://www.terrapinphoto.com/duomo_from_uffizi.html
>http://www.terrapinphoto.com/log_fence_near_wayah_bald....
>http://www.terrapinphoto.com/kinsman_cairn2.html
>http://www.terrapinphoto.com/nahmakanta_lake.html
>http://www.terrapinphoto.com/cadillac_flowers.html
>http://www.terrapinphoto.com/acadia.html
>http://www.terrapinphoto.com/acadia_sunset2.html
>http://www.terrapinphoto.com/tide_pool.html
>http://www.terrapinphoto.com/red_cliff.html


I think we must disagree on the definition of
"blown" highlights. I prefer to use the term
clipped, if you don't mind <G>.

"Clipped" to me, means a signficant count of
pixels in one or more color channels at 0 or 255,
ie. a histogram piled up against either wall.

I found three images from the above list with
some degree of clipping. On that basis, I'm
happy to dismiss those three as lousy scans.
(But nothing nearly as bad as your first
sanjuan image.)

I plucked several of these images back off the
site and selected a 30x30 pixel region from the
brightest portion of the sky. The histograms
of those regions were perfectly reasonable
(to my thinking) in every color channel. I'm
curious what you'd have expected to see
differently had these been 16-bit scans.

I use as much tonal range as I dare. If I
allocate more tones for the highlights, or
for the shadows, I've got to steal them from
somewhere else. Surely you know all that.

You can't look at a given image and presume
that a given region should have a given a
specific median or standard deviation of
tones. As the "artist," I get to choose
how the tones are distributed.

The only way I know to get around this is
with selective tonal control or contrast
masking, which I do use from time to time.

In my experience, scanning and editing in
16-bit isn't going to change a thing. But
I'll tell you what... I'm ready to challenge
my own assumptions and see if I can make a
few more rigorous tests. All these negatives
are still around, and the scanner's ready to
roll.

Thanks for the challenge. I'll report back
when I've learned a bit more.


rafe b.
http://www.terrapinphoto.com
Anonymous
March 18, 2005 11:04:51 PM

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

rafe bustin wrote:

> On Thu, 17 Mar 2005 20:03:05 -0700, "Roger N. Clark (change username
> to rnclark)" <username@qwest.net> wrote:
>
>
>
>>Cloud highlights blown:
>>http://www.terrapinphoto.com/chengs_tree.html
>>http://www.terrapinphoto.com/marcydam2.html
>>http://www.terrapinphoto.com/mt_dix_grass.html
>>http://www.terrapinphoto.com/chim_pond_sunset_reflectio...
>>http://www.terrapinphoto.com/bridlepath_leaves_solarize...
>>http://www.terrapinphoto.com/old_lobster_trap.html
>>http://www.terrapinphoto.com/morocco_cityscape.html
>>http://www.terrapinphoto.com/duomo_from_uffizi.html
>>http://www.terrapinphoto.com/log_fence_near_wayah_bald....
>>http://www.terrapinphoto.com/kinsman_cairn2.html
>>http://www.terrapinphoto.com/nahmakanta_lake.html
>>http://www.terrapinphoto.com/cadillac_flowers.html
>>http://www.terrapinphoto.com/acadia.html
>>http://www.terrapinphoto.com/acadia_sunset2.html
>>http://www.terrapinphoto.com/tide_pool.html
>>http://www.terrapinphoto.com/red_cliff.html
>
>
>
> I think we must disagree on the definition of
> "blown" highlights. I prefer to use the term
> clipped, if you don't mind <G>.
>
> "Clipped" to me, means a signficant count of
> pixels in one or more color channels at 0 or 255,
> ie. a histogram piled up against either wall.

It is more than that, and I don't necessarily go by the
histogram. Besides a clipped high end, those values just
darker than the clip point will be highly posterized by
an 8-bit scan. This is because the shape of the
film's chacacteristic curve is becoming very flat at the
high end, so 8-bit intensity changes turn out to be
missing a lot of detaill in the highlights.
You can recover it to some degree with clouds
because you can convert to 16-bit, select the clouds, stretch
them (as if you applied a split density filter; note that is
not a simple intensity reduction because with a split density
the image would fall on a different part of the film's
characteristic curve). For 8-bit images (in 16-bit mode)
blur the clouds a little (not to much to lose detail), and
it averages between the 8-bit values. But a 16-bit scan would
give you more information to begin with.

> I found three images from the above list with
> some degree of clipping. On that basis, I'm
> happy to dismiss those three as lousy scans.
> (But nothing nearly as bad as your first
> sanjuan image.)
>
> I plucked several of these images back off the
> site and selected a 30x30 pixel region from the
> brightest portion of the sky. The histograms
> of those regions were perfectly reasonable
> (to my thinking) in every color channel. I'm
> curious what you'd have expected to see
> differently had these been 16-bit scans.
>
> I use as much tonal range as I dare. If I
> allocate more tones for the highlights, or
> for the shadows, I've got to steal them from
> somewhere else. Surely you know all that.

Ah, but it is not a matter of tonal range as it is
in dividing that tonal range into more levels. That is the
different between 8-bit and 16-bit. With 16-bit, you
scan all the possible detail there is in the image
(true because film is "noisy") so 16-bit digitizes that
noise (intensity variations due to grain). Then in
your photo editor, you can select regions (like the sky
as you would with a split density filter on the camera)
and adjust the dynamic range so it can be viewed
on a monitor and printed in a print. There is no one
stretch for an image. Most (close to all?) images need
some selective "dodging and burning" to print well.
Read Ansel Adam's "The Print."

> You can't look at a given image and presume
> that a given region should have a given a
> specific median or standard deviation of
> tones. As the "artist," I get to choose
> how the tones are distributed.

Yes.

> The only way I know to get around this is
> with selective tonal control or contrast
> masking, which I do use from time to time.

Yes, see above.

> In my experience, scanning and editing in
> 16-bit isn't going to change a thing. But
> I'll tell you what... I'm ready to challenge
> my own assumptions and see if I can make a
> few more rigorous tests. All these negatives
> are still around, and the scanner's ready to
> roll.

That's great.

> Thanks for the challenge. I'll report back
> when I've learned a bit more.

If you would like, you could post a small, say 1000x1000 pixel
image at 16-bit (tif or psd), original scan and I'll work on it for you,
so I can show you what I mean. This could be a non-publicized
link so the whole world does not grab it. Then, if you like,
you can post the results.

> rafe b.
> http://www.terrapinphoto.com

When I get some time, I'll pull out some of my 8,000 to 11,000 dpi
drum scans for your web site--might be a couple of months--
remind me then. The next two months are real busy.

Roger
Anonymous
March 19, 2005 1:59:52 AM

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

On Fri, 18 Mar 2005 20:04:51 -0700, "Roger N. Clark (change username
to rnclark)" <username@qwest.net> wrote:


>Ah, but it is not a matter of tonal range as it is
>in dividing that tonal range into more levels. That is the
>different between 8-bit and 16-bit. With 16-bit, you
>scan all the possible detail there is in the image
>(true because film is "noisy") so 16-bit digitizes that
>noise (intensity variations due to grain). Then in
>your photo editor, you can select regions (like the sky
>as you would with a split density filter on the camera)
>and adjust the dynamic range so it can be viewed
>on a monitor and printed in a print. There is no one
>stretch for an image. Most (close to all?) images need
>some selective "dodging and burning" to print well.
>Read Ansel Adam's "The Print."


I think I'm beginning to understand some
of our differences.

For starters, I use selective tonal
manipulation sparingly. Perhaps I lack
the talent to do it well. Or perhaps I'm
overly sensitive to the negative effects
when it's not done well. Or maybe it's
due to the first serious book I read when
I started down this road, years ago, and
the practices encouraged/discouraged by
the author (again, Dan Margulis.)

One of the simpler and more effective
techniques that I use for a "classic"
landscape is to make an alpha channel
consisting of a simple gradient, and
apply my tonal adjustments through that
alpha channel. Making and placing the
gradient is critical, of course. I think
of this as applying a graduated-ND
filter, after the fact.

I'm not going to comment on the 8/16 bit
issue now. Suffice to say, I've been
working with film scans for some time,
and have tried, on numerous occasions, to
convince myself of the need for, or value
of 16-bit scans.

I'm fully aware of what happens to tones
as a consequence of Curves/Levels
adjustments, and the (rather simple)
mathematical argument in favor of having
more codes to work with. I simply haven't
seen the benefit, at least in the way I
practice the "digital darkroom."


rafe b.
http://www.terrapinphoto.com
Anonymous
March 19, 2005 4:24:31 PM

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

"rafe bustin" <rafeb@speakeasy.net> wrote:
>
> I think I'm beginning to understand some
> of our differences.

The rest of us figured it out ages ago. Roger likes dramatic and Rafe likes
subtle. Both do what they like well, and see the other as completely missing
the important stuff that are quite pleased to be successfully getting into
their respective images.

Knock yourselves out, guys! The rest of us are enjoying both the photos and
the fireworks.

David J. Littleboy
Tokyo, Japan
Anonymous
March 23, 2005 7:31:28 AM

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

On Sat, 19 Mar 2005 13:24:31 +0900, "David J. Littleboy"
<davidjl@gol.com> wrote:

>
>"rafe bustin" <rafeb@speakeasy.net> wrote:
>>
>> I think I'm beginning to understand some
>> of our differences.
>
>The rest of us figured it out ages ago. Roger likes dramatic and Rafe likes
>subtle. Both do what they like well, and see the other as completely missing
>the important stuff that are quite pleased to be successfully getting into
>their respective images.
>
>Knock yourselves out, guys! The rest of us are enjoying both the photos and
>the fireworks.
>
>David J. Littleboy
>Tokyo, Japan
>
I'm certain my observations will not be well accepted, but anyhow here
they are. Of all the 35mm slides I've been privileged to see,
including some of my own, none of them are really worthy of this
argument. Most lack the fine detail that this depth of scanning
precision warrants. But then I'm only an amateur photographer and my
slides plus those of my acquaintances fit this category.

When I see some of the details the current crop of good digital
cameras produce, I'm ready to forget scanning of any slides. They
just aren't worth it the trouble, unless they contain something that
we just can't allow to be lost.

Olin McDaniel
!