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20D fast "standard" lens

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Anonymous
December 20, 2004 1:15:04 PM

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

I just made the switch to a dSLR and am only now experiencing the similarities
and, more importantly, the DISimilarities between digital and the film world I
am leaving behind.

I wish to acquire a lens for my new Canon 20D that will provide the same
perspective as my old, reliable 50mm f1.4 attached to my AE1 or T90.

I wish to equip the camera for flashless work during a grandchild's birth. I
used my AE1 and the above-mentioned lens for the flashless shoot of the baby's
mother's birth. I'd like to send the proud father into the room with my
camera equipped to do the best ambient shoot possible of my third grandchild.

What lens (filter?) do you suggest. How about ISO?

TIA!
:) 
JR

More about : 20d fast standard lens

Anonymous
December 20, 2004 7:21:09 PM

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

Jim Redelfs <jim.redelfs@redelfs.com> wrote in
news:jim.redelfs-49F2C0.10150420122004@news.central.cox.net:

> I just made the switch to a dSLR and am only now experiencing the
> similarities and, more importantly, the DISimilarities between digital
> and the film world I am leaving behind.
>
> I wish to acquire a lens for my new Canon 20D that will provide the
> same perspective as my old, reliable 50mm f1.4 attached to my AE1 or
> T90.

Then get another 50mm f/1.4 lense. If you want the same -perspective-, you
get the same focal length.
If you want the same -field of view-, then you need a different lense.

> I wish to equip the camera for flashless work during a grandchild's
> birth. I used my AE1 and the above-mentioned lens for the flashless
> shoot of the baby's mother's birth. I'd like to send the proud father
> into the room with my camera equipped to do the best ambient shoot
> possible of my third grandchild.
>
> What lens (filter?) do you suggest. How about ISO?

See if you can find out ahead of time what type of lights they use in the
room. From there, you can adjust the white-balance on your camera and do
without filters.

--
http://www.neopets.com/refer.phtml?username=moosespet
Anonymous
December 20, 2004 7:29:06 PM

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

In article <jim.redelfs-49F2C0.10150420122004@news.central.cox.net>,
Jim Redelfs <jim.redelfs@redelfs.com> wrote:

>I wish to acquire a lens for my new Canon 20D that will provide the same
>perspective as my old, reliable 50mm f1.4 attached to my AE1 or T90.
>
>I wish to equip the camera for flashless work during a grandchild's birth. I
>used my AE1 and the above-mentioned lens for the flashless shoot of the baby's
>mother's birth. I'd like to send the proud father into the room with my
>camera equipped to do the best ambient shoot possible of my third grandchild.

To get the same field of view (and therefore the same perspective on th
esame subject), you'll need something around a 28 or 35mm lens. Canon do
fast primes in both these lengths, but sadly nothing as inexpensive as the
50mm f/1.8.

>What lens (filter?) do you suggest. How about ISO?

You should get excellent results up to 800 ISO, and decent results at 1600
ISO. Suggest you shoot raw. Even if you don't want the raw images now, you
may end up regretting not having used it in the future.
Related resources
Anonymous
December 20, 2004 7:43:30 PM

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

>From: Jim Redelfs jim.redelfs@redelfs.com

>I wish to acquire a lens for my new Canon 20D that will provide the same
>perspective as my old, reliable 50mm f1.4 attached to my AE1 or T90.

Try the 35 mm f/2 to get a similar field-of-view to your 50 mm with 35 mm ...
this is an excellent lens, small, light, fast with good optics.

>How about ISO?

Jack it up until your shutter speed is fast enough to freeze subject motion?
If the ISO gets to 800 or higher you might want to invest in noise removal
software like Neat Image or similar.

Bill
Anonymous
December 20, 2004 8:03:56 PM

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

Jim Redelfs wrote:

> I just made the switch to a dSLR and am only now experiencing the similarities
> and, more importantly, the DISimilarities between digital and the film world I
> am leaving behind.
>
> I wish to acquire a lens for my new Canon 20D that will provide the same
> perspective as my old, reliable 50mm f1.4 attached to my AE1 or T90.
>
> I wish to equip the camera for flashless work during a grandchild's birth. I
> used my AE1 and the above-mentioned lens for the flashless shoot of the baby's
> mother's birth. I'd like to send the proud father into the room with my
> camera equipped to do the best ambient shoot possible of my third grandchild.
>
> What lens (filter?) do you suggest. How about ISO?
>
No filter needed. ISO ca. 800. Shoot in RAW and large jpeg. I'd be
inclined to use the 1.4 50mm, or the kit lens for these shots, and leave
the WB set to auto, unless you can get in early and do a custom WB. With
RAW conversion, you can tweak the WB to be exactly on minutes after
loading them onto the computer.

--
John McWilliams
Anonymous
December 20, 2004 8:35:26 PM

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

Chris Brown <cpbrown@ntlworld.no_uce_please.com> wrote in
news:mqaj92-cin.ln1@narcissus.dyndns.org:

> In article <jim.redelfs-49F2C0.10150420122004@news.central.cox.net>,
> Jim Redelfs <jim.redelfs@redelfs.com> wrote:
>
>>I wish to acquire a lens for my new Canon 20D that will provide the
>>same perspective as my old, reliable 50mm f1.4 attached to my AE1 or
>>T90.
>>
>>I wish to equip the camera for flashless work during a grandchild's
>>birth. I used my AE1 and the above-mentioned lens for the flashless
>>shoot of the baby's mother's birth. I'd like to send the proud father
>>into the room with my camera equipped to do the best ambient shoot
>>possible of my third grandchild.
>
> To get the same field of view (and therefore the same perspective on
> th esame subject), you'll need something around a 28 or 35mm lens.
> Canon do fast primes in both these lengths, but sadly nothing as
> inexpensive as the 50mm f/1.8.

No, that's 100% wrong. When you change the focal length and retain the
field of view, you change perspective.


--
http://www.neopets.com/refer.phtml?username=moosespet
Anonymous
December 20, 2004 8:38:51 PM

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

On Mon, 20 Dec 2004 17:35:26 GMT, Jon Pike wrote:

> Chris Brown <cpbrown@ntlworld.no_uce_please.com> wrote in
> news:mqaj92-cin.ln1@narcissus.dyndns.org:
>
>> In article <jim.redelfs-49F2C0.10150420122004@news.central.cox.net>,
>> Jim Redelfs <jim.redelfs@redelfs.com> wrote:
>>
>>>I wish to acquire a lens for my new Canon 20D that will provide the
>>>same perspective as my old, reliable 50mm f1.4 attached to my AE1 or
>>>T90.
>>>
>>>I wish to equip the camera for flashless work during a grandchild's
>>>birth. I used my AE1 and the above-mentioned lens for the flashless
>>>shoot of the baby's mother's birth. I'd like to send the proud father
>>>into the room with my camera equipped to do the best ambient shoot
>>>possible of my third grandchild.
>>
>> To get the same field of view (and therefore the same perspective on
>> th esame subject), you'll need something around a 28 or 35mm lens.
>> Canon do fast primes in both these lengths, but sadly nothing as
>> inexpensive as the 50mm f/1.8.
>
> No, that's 100% wrong. When you change the focal length and retain the
> field of view, you change perspective.

The only thing that effects perspective is the distance between the camera
and the subject. Lens focal length plays no part, it effects only the field
of view.

--
John Bean

The computer is a moron (Peter Drucker)
Anonymous
December 20, 2004 8:47:55 PM

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

Jon Pike wrote:
> Jim Redelfs <jim.redelfs@redelfs.com> wrote in
> news:jim.redelfs-49F2C0.10150420122004@news.central.cox.net:
>
>> I just made the switch to a dSLR and am only now experiencing the
>> similarities and, more importantly, the DISimilarities between
>> digital and the film world I am leaving behind.
>>
>> I wish to acquire a lens for my new Canon 20D that will provide the
>> same perspective as my old, reliable 50mm f1.4 attached to my AE1 or
>> T90.
>
> Then get another 50mm f/1.4 lense. If you want the same
> -perspective-, you get the same focal length.
> If you want the same -field of view-, then you need a different lense.
>

Sorry, but your advice is at best misleading. What you say is true IF
the lens is used at the same distance. However most of the time a
photographer will frame the subject and move closer or further away to
archive the same coverage. Since the user of a 20D would need to move
further way using the same lens as a full frame 35 mm the perspective would
be different.

The use of a lens about 31 mm (28 or 35 should do nicely) would give the
same coverage at the same distance and it would also give about the same
perspective.

In real life situations, I believe that the perspective issue should be
brought up only when it seems needed to avoid excessive confusion. In this
case the user should get the results they want (including the perspective
they likely did not think about) with the proper focal length lens of around
28-35 mm.

>> I wish to equip the camera for flashless work during a grandchild's
>> birth. I used my AE1 and the above-mentioned lens for the flashless
>> shoot of the baby's mother's birth. I'd like to send the proud
>> father into the room with my camera equipped to do the best ambient
>> shoot possible of my third grandchild.
>>
>> What lens (filter?) do you suggest. How about ISO?
>
> See if you can find out ahead of time what type of lights they use in
> the room. From there, you can adjust the white-balance on your camera
> and do without filters.

Very good advice.

Jim, color balance in most digitals, including the 20D can be manually
adjusted via the white balance as suggested and this would be the most
accurate method. Your manual will explain how. On the other hand if you
can't determine the type of light ahead of time, or the lighting is mixed,
you will want to let the camera to do its own guesswork and it should do OK.
You don't really want to need to get the manual out at the hospital. I
believe most auto settings have auto white balance, but you can check the
manual to make sure.

I really need to spend a little more time with my 20D to get all this
stuff in my head.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math
Anonymous
December 20, 2004 8:52:07 PM

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

Jon Pike wrote:
> Chris Brown <cpbrown@ntlworld.no_uce_please.com> wrote in
> news:mqaj92-cin.ln1@narcissus.dyndns.org:
>
>> In article <jim.redelfs-49F2C0.10150420122004@news.central.cox.net>,
>> Jim Redelfs <jim.redelfs@redelfs.com> wrote:
>>
>>> I wish to acquire a lens for my new Canon 20D that will provide the
>>> same perspective as my old, reliable 50mm f1.4 attached to my AE1 or
>>> T90.
>>>
>>> I wish to equip the camera for flashless work during a grandchild's
>>> birth. I used my AE1 and the above-mentioned lens for the flashless
>>> shoot of the baby's mother's birth. I'd like to send the proud
>>> father into the room with my camera equipped to do the best ambient
>>> shoot possible of my third grandchild.
>>
>> To get the same field of view (and therefore the same perspective on
>> th esame subject), you'll need something around a 28 or 35mm lens.
>> Canon do fast primes in both these lengths, but sadly nothing as
>> inexpensive as the 50mm f/1.8.
>
> No, that's 100% wrong. When you change the focal length and retain the
> field of view, you change perspective.

Sorry Jon, when you change the focal length and retain the field of
view, you don't change perspective. When you change the focal length and
retain the same distance, you change the perspective.

Think of the portrait photographer. To flatten the face of someone with
a large nose for example, they will use a longer lens and step back, keeping
the face the same size. Two photographers standing side by side one with a
135 mm on a 4x5 and one with a 50 mm on a full frame 35mm camera will end up
with the same perspective and coverage.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math
Anonymous
December 20, 2004 9:12:10 PM

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

Joseph Meehan wrote:
>
> Jim, color balance in most digitals, including the 20D can be manually
> adjusted via the white balance as suggested and this would be the most
> accurate method. Your manual will explain how. On the other hand if you
> can't determine the type of light ahead of time, or the lighting is mixed,
> you will want to let the camera to do its own guesswork and it should do OK.
> You don't really want to need to get the manual out at the hospital. I
> believe most auto settings have auto white balance, but you can check the
> manual to make sure.
>
> I really need to spend a little more time with my 20D to get all this
> stuff in my head.

In color critical shots, with little or no review time, shooting in the
RAW mode kills a lot of birds with one stone. A few test shots at the
hospital in rooms with similar lighting as the delivery room is not a
bad idea, also.

--
John McWilliams
Anonymous
December 20, 2004 9:25:42 PM

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

Jon Pike wrote:

yada yada.

F'r'eaven's sake! The OP asked a fine question, with the word
"perspective" easily understood by everyone in its context. Then the
like of Pike makes a freaking Federal Case out of it, just as he's done
with all the NG's in Calgary and other parts of Canada where he's become
persona non grata.

--
John McWilliams
December 20, 2004 9:41:44 PM

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

Jon Pike <Anonomoose@spamlesshotmail.com> wrote in
news:Xns95C56C115A22FLessThanPerfectInc@24.71.223.159:

> No, that's 100% wrong. When you change the focal length and retain the
> field of view, you change perspective.
>

You are mistaken. Perspective refers to relative size and position of
objects in the picture. It is determined entirely by lens position and the
direction the lens is pointed in.

If you set your camera on a tripod, and take photos with every lens you
own, then all the resulting photos will have the same perspective,
excepting the minor variations in lens nodal point.

Bob
Anonymous
December 20, 2004 10:29:37 PM

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

In article <Xns95C55F7937313LessThanPerfectInc@24.71.223.159>,
Jon Pike <Anonomoose@spamlesshotmail.com> wrote:
>
>Then get another 50mm f/1.4 lense. If you want the same -perspective-, you
>get the same focal length.

No, if you want the same perspective, you stand in the same place to take
the photograph. The required framing then dicatates the choice of lens.

If you then want to frame the same subject in the same way with the same
perspective, you need different lenses with a 20D than you do with a 35mm
EOS. Given a 35mm EOS with a 50mm lens mounted, you will need a 20D with a
31mm focal length to get the same framing.
Anonymous
December 20, 2004 10:29:37 PM

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

In article <Xns95C56C115A22FLessThanPerfectInc@24.71.223.159>,
Jon Pike <Anonomoose@spamlesshotmail.com> wrote:
>
>No, that's 100% wrong. When you change the focal length and retain the
>field of view, you change perspective.

Your understanding of optics is broken. Perspective is the relative apparent
size of objects in a view. This varies based on their distance to the
observer and nothing else. The focal length of a lens used to project an
image at the observer's position has no effect on this. For a given
projection size, it simply varies the field of view, leaving perspective
unchanged.

Perspective is a direct consequence of light traveling in straight lines.
The lens you mount on your camera will make no difference to the path taken
between the subject and the front lens element.
Anonymous
December 20, 2004 10:31:44 PM

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

Get a fast 35mm. An f2 will do the job. It will give you the same exposure
as your old 50mm f1.4, as you can drop down one stop on the shutter using
the same ISO.
Anonymous
December 20, 2004 10:31:45 PM

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

In article <BDECD94A.ED8D%teflon@bluebottlefly.com>,
teflon <teflon@bluebottlefly.com> wrote:

> Get a fast 35mm. An f2 will do the job. It will give you the same exposure
> as your old 50mm f1.4, as you can drop down one stop on the shutter using
> the same ISO.

Welcome advice, all. Thenk-kew! :) 

It is entirely likely that MY idea of perspective may be wrong. I'm just
looking for a good, FAST "standard" <coff,hack> lens that will deliver the
same results (or as close as possible) as I was used to with my film system,
including what's REALLY on the "4x6" uncropped frame.

Am I to understand that these days, f2 is a fast-enough lens for indoor
shooting without a flash?

MANY moons ago I paid dearly to get the f1.4 lens instead of the more
"standard" f1.8 for that extra ...what 1/3 (1/4?) stop?

I consider it a given that lighting will be adequate, if not bright, for
ambient light work in a delivery room situation.

<http://consumer.usa.canon.com/ir/controller?act=ModelDe...
&modelid=7304>

OK. Forget it. I just checked B&H and there's about $900US dif between the
f1.4 and the f2 lens. That just made my choice for me. <sigh>

Thanks, all!
:) 
JR
Anonymous
December 20, 2004 10:31:46 PM

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

Jim Redelfs wrote:


> MANY moons ago I paid dearly to get the f1.4 lens instead of the more
> "standard" f1.8 for that extra ...what 1/3 (1/4?) stop?

If you don't mind paying **dearly** again, Canon makes a 35mm f/1.4
They go new for about $1200.00 US :-)

As for using the f/2.0... With the low noise of the 20D, you can shoot at
ISO 400-800 and get good results. The high ISOs should negate the loss of
light if you choose the f/2.0 version... But if DOF is an important factor
(for portrait work etc), you should go with the f/1.4
Anonymous
December 20, 2004 10:37:15 PM

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

On 20/12/04 7:29 pm, in article d2kj92-jsn.ln1@narcissus.dyndns.org, "Chris
Brown" <cpbrown@ntlworld.no_uce_please.com> wrote:

> In article <Xns95C56C115A22FLessThanPerfectInc@24.71.223.159>,
> Jon Pike <Anonomoose@spamlesshotmail.com> wrote:
>>
>> No, that's 100% wrong. When you change the focal length and retain the
>> field of view, you change perspective.
>
> Your understanding of optics is broken. Perspective is the relative apparent
> size of objects in a view. This varies based on their distance to the
> observer and nothing else. The focal length of a lens used to project an
> image at the observer's position has no effect on this. For a given
> projection size, it simply varies the field of view, leaving perspective
> unchanged.
>
> Perspective is a direct consequence of light traveling in straight lines.
> The lens you mount on your camera will make no difference to the path taken
> between the subject and the front lens element.

He said when you "retain the field of view" - which means moving position.
Anonymous
December 20, 2004 11:03:21 PM

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

On Mon, 20 Dec 2004 19:37:15 GMT, teflon wrote:

> On 20/12/04 7:29 pm, in article d2kj92-jsn.ln1@narcissus.dyndns.org, "Chris
> Brown" <cpbrown@ntlworld.no_uce_please.com> wrote:
>
>> In article <Xns95C56C115A22FLessThanPerfectInc@24.71.223.159>,
>> Jon Pike <Anonomoose@spamlesshotmail.com> wrote:
>>>
>>> No, that's 100% wrong. When you change the focal length and retain the
>>> field of view, you change perspective.
>>
>> Your understanding of optics is broken. Perspective is the relative apparent
>> size of objects in a view. This varies based on their distance to the
>> observer and nothing else. The focal length of a lens used to project an
>> image at the observer's position has no effect on this. For a given
>> projection size, it simply varies the field of view, leaving perspective
>> unchanged.
>>
>> Perspective is a direct consequence of light traveling in straight lines.
>> The lens you mount on your camera will make no difference to the path taken
>> between the subject and the front lens element.
>
> He said when you "retain the field of view" - which means moving position.

No, because the object image is a different size - smaller on the dSLR, so
retaining the same position *and* field of view requires a different focal
length. The perspective is unchanged.

--
John Bean

The most overlooked advantage to owning a computer is that if they foul up
there's no law against wacking them around a little (Joe Martin)
Anonymous
December 21, 2004 12:42:52 AM

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

"Jon Pike" <Anonomoose@spamlesshotmail.com> wrote in message
news:Xns95C56C115A22FLessThanPerfectInc@24.71.223.159...
> Chris Brown <cpbrown@ntlworld.no_uce_please.com> wrote in
> news:mqaj92-cin.ln1@narcissus.dyndns.org:
SNIP
>> To get the same field of view (and therefore the same perspective
>> on
>> th esame subject), you'll need something around a 28 or 35mm lens.
>> Canon do fast primes in both these lengths, but sadly nothing as
>> inexpensive as the 50mm f/1.8.
>
> No, that's 100% wrong. When you change the focal length and retain
> the
> field of view, you change perspective.

Reading comprehension seems difficult for some. "To get the same" FOV,
is something different from "and retain the" FOV. Of course there is a
possibility that the misreading is intentional.

Bart
Anonymous
December 21, 2004 1:10:08 AM

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

On 20/12/04 8:03 pm, in article al9lvmo5bcwj.dlg@waterfoot.net, "John Bean"
<john@waterfoot.net> wrote:

>> He said when you "retain the field of view" - which means moving position.

> No, because the object image is a different size - smaller on the dSLR, so
> retaining the same position *and* field of view requires a different focal
> length. The perspective is unchanged.

You're right. I'm still thinking film.

Anyway, he's sorted now.
Anonymous
December 21, 2004 1:28:27 AM

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

>From: Jim Redelfs jim.redelfs@redelfs.com

>Am I to understand that these days, f2 is a fast-enough lens for indoor
>shooting without a flash?

With digital you can boost the ISO a stop if need be and remove the noise
(digital grain) later, so it's easier than with film.
Anonymous
December 21, 2004 1:29:55 AM

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

In article <BDECDA94.ED94%teflon@bluebottlefly.com>,
teflon <teflon@bluebottlefly.com> wrote:
>
>He said when you "retain the field of view" - which means moving position.

No it doesn't. Field of view is the angle you can see through the lens, and
is independent of where you stand.
Anonymous
December 21, 2004 1:49:56 AM

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

On 20/12/04 10:29 pm, in article sduj92-a6o.ln1@narcissus.dyndns.org, "Chris
Brown" <cpbrown@ntlworld.no_uce_please.com> wrote:

> In article <BDECDA94.ED94%teflon@bluebottlefly.com>,
> teflon <teflon@bluebottlefly.com> wrote:
>>
>> He said when you "retain the field of view" - which means moving position.
>
> No it doesn't. Field of view is the angle you can see through the lens, and
> is independent of where you stand.

You're both right.
Anonymous
December 21, 2004 2:22:12 AM

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

John Bean <john@waterfoot.net> wrote in
news:11oh1hfzb47sn$.dlg@waterfoot.net:

> On Mon, 20 Dec 2004 17:35:26 GMT, Jon Pike wrote:
>
>> Chris Brown <cpbrown@ntlworld.no_uce_please.com> wrote in
>> news:mqaj92-cin.ln1@narcissus.dyndns.org:
>>
>>> In article <jim.redelfs-49F2C0.10150420122004@news.central.cox.net>,
>>> Jim Redelfs <jim.redelfs@redelfs.com> wrote:
>>>
>>>>I wish to acquire a lens for my new Canon 20D that will provide the
>>>>same perspective as my old, reliable 50mm f1.4 attached to my AE1 or
>>>>T90.
>>>>
>>>>I wish to equip the camera for flashless work during a grandchild's
>>>>birth. I used my AE1 and the above-mentioned lens for the flashless
>>>>shoot of the baby's mother's birth. I'd like to send the proud
>>>>father into the room with my camera equipped to do the best ambient
>>>>shoot possible of my third grandchild.
>>>
>>> To get the same field of view (and therefore the same perspective on
>>> th esame subject), you'll need something around a 28 or 35mm lens.
>>> Canon do fast primes in both these lengths, but sadly nothing as
>>> inexpensive as the 50mm f/1.8.
>>
>> No, that's 100% wrong. When you change the focal length and retain
>> the field of view, you change perspective.
>
> The only thing that effects perspective is the distance between the
> camera and the subject. Lens focal length plays no part, it effects
> only the field of view.

That too, is 100% wrong. lenses affect a lot more than just the field of
view.


--
http://www.neopets.com/refer.phtml?username=moosespet
Anonymous
December 21, 2004 2:29:20 AM

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

"Joseph Meehan" <sligojoe_Spamno@hotmail.com> wrote in
news:bjExd.4539$vb7.4167@fe1.columbus.rr.com:

> Jon Pike wrote:
>> Chris Brown <cpbrown@ntlworld.no_uce_please.com> wrote in
>> news:mqaj92-cin.ln1@narcissus.dyndns.org:
>>
>>> In article <jim.redelfs-49F2C0.10150420122004@news.central.cox.net>,
>>> Jim Redelfs <jim.redelfs@redelfs.com> wrote:
>>>
>>>> I wish to acquire a lens for my new Canon 20D that will provide the
>>>> same perspective as my old, reliable 50mm f1.4 attached to my AE1
>>>> or T90.
>>>>
>>>> I wish to equip the camera for flashless work during a grandchild's
>>>> birth. I used my AE1 and the above-mentioned lens for the
>>>> flashless shoot of the baby's mother's birth. I'd like to send the
>>>> proud father into the room with my camera equipped to do the best
>>>> ambient shoot possible of my third grandchild.
>>>
>>> To get the same field of view (and therefore the same perspective on
>>> th esame subject), you'll need something around a 28 or 35mm lens.
>>> Canon do fast primes in both these lengths, but sadly nothing as
>>> inexpensive as the 50mm f/1.8.
>>
>> No, that's 100% wrong. When you change the focal length and retain
>> the field of view, you change perspective.
>
> Sorry Jon, when you change the focal length and retain the field
> of
> view, you don't change perspective. When you change the focal length
> and retain the same distance, you change the perspective.

Again, 100% wrong.
Here's proof:

http://members.shaw.ca/anonomoose/perspective/

each picture is named for the length of the lense used to take it.
See how the subject stays roughly the same, but the perspective changes a
great deal?
Images taken from:
Camera and Lens - The Creative Approach
by Ansel Adams

My scanner doesn't do his images justice, but you -ought- to understand
by now.

--
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December 21, 2004 2:29:21 AM

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

Jon Pike <Anonomoose@spamlesshotmail.com> writes:

> "Joseph Meehan" <sligojoe_Spamno@hotmail.com> wrote in
> news:bjExd.4539$vb7.4167@fe1.columbus.rr.com:
>
> > Jon Pike wrote:

(snip)

> >> No, that's 100% wrong. When you change the focal length and retain
> >> the field of view, you change perspective.
> >
> > Sorry Jon, when you change the focal length and retain the field of
> > view, you don't change perspective. When you change the focal
> > length and retain the same distance, you change the perspective.
>
> Again, 100% wrong.
> Here's proof:
>
> http://members.shaw.ca/anonomoose/perspective/
>
> each picture is named for the length of the lense used to take it.
> See how the subject stays roughly the same, but the perspective changes a
> great deal?
> Images taken from:
> Camera and Lens - The Creative Approach
> by Ansel Adams
>
> My scanner doesn't do his images justice, but you -ought- to understand
> by now.

Uh... what exactly, in your humble opinion, is happening to the field
of view in those pictures when you go from 40mm to 250mm? Do you really
think each picture was shot from the same distance?
--
ego vidi stultum firma radice et maledixi pulchritudini eius statim
December 21, 2004 2:29:22 AM

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

Florian <petafrog@evilemail.com> wrote in
news:m3pt14cmvm.fsf@tiainen.domain.invalid:

> Jon Pike <Anonomoose@spamlesshotmail.com> writes:
>
>> "Joseph Meehan" <sligojoe_Spamno@hotmail.com> wrote in
>> news:bjExd.4539$vb7.4167@fe1.columbus.rr.com:
>>
>> http://members.shaw.ca/anonomoose/perspective/
>>
>> each picture is named for the length of the lense used to take it.
>> See how the subject stays roughly the same, but the perspective
>> changes a great deal?


> Uh... what exactly, in your humble opinion, is happening to the field
> of view in those pictures when you go from 40mm to 250mm? Do you
> really think each picture was shot from the same distance?

Just looking at the 40mm and the 250mm pictures, it is clear that the
taking position is different, causing a change in perspective. It doesn't
matter what lens is used -- for any given lens position/orientation there
is only one perspective.


--
Delete the inverse SPAM to reply
Anonymous
December 21, 2004 2:31:28 AM

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

bob <Jwx1.nothing@bellsouth.net> wrote in
news:Xns95C58B9A44422j123w123x123@216.77.188.18:

> Jon Pike <Anonomoose@spamlesshotmail.com> wrote in
> news:Xns95C56C115A22FLessThanPerfectInc@24.71.223.159:
>
>> No, that's 100% wrong. When you change the focal length and retain
>> the field of view, you change perspective.
>>
>
> You are mistaken. Perspective refers to relative size and position of
> objects in the picture. It is determined entirely by lens position and
> the direction the lens is pointed in.
>
> If you set your camera on a tripod, and take photos with every lens
> you own, then all the resulting photos will have the same perspective,
> excepting the minor variations in lens nodal point.

If that were the case, then how do you explain the pictures I posted here?
http://members.shaw.ca/anonomoose/perspective/

The subject, and field of view stay as much the same as possible, but the
use of longer lense changes the perspective.
Pay special attention to the two little "stumps" in the foreground.

--
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Anonymous
December 21, 2004 2:31:29 AM

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

Jon Pike wrote:

> bob <Jwx1.nothing@bellsouth.net> wrote in
> news:Xns95C58B9A44422j123w123x123@216.77.188.18:
>
>
>>Jon Pike <Anonomoose@spamlesshotmail.com> wrote in
>>news:Xns95C56C115A22FLessThanPerfectInc@24.71.223.159:
>>
>>
>>>No, that's 100% wrong. When you change the focal length and retain
>>>the field of view, you change perspective.
>>>
>>
>>You are mistaken. Perspective refers to relative size and position of
>>objects in the picture. It is determined entirely by lens position and
>>the direction the lens is pointed in.
>>
>>If you set your camera on a tripod, and take photos with every lens
>>you own, then all the resulting photos will have the same perspective,
>>excepting the minor variations in lens nodal point.
>
>
> If that were the case, then how do you explain the pictures I posted here?
> http://members.shaw.ca/anonomoose/perspective/
>
> The subject, and field of view stay as much the same as possible, but the
> use of longer lense changes the perspective.
> Pay special attention to the two little "stumps" in the foreground.
>

Jon,
With each change to a longer focal length lens, the photographer
had to move further away from the subject in order to make
the subject the same size. It is the change in distance that
changes perspective, not the focal length of the lens.
To prove this, use the 40mm lens at the same position where
the 250mm lens image was obtained at. Then enlarge the
center portion of the image so the subject is the same size
as in all the other photos. You will see that the perspective
matches the image obtained with the 250mm lens. The two
lenses, 40mm and 250 mm lenses produce the same image when
photographed from the same location, just
one image is smaller than the other. But if enlarged
and cropped would be indistinguishable from the longer focal
length image (ignoring grain/image quality issues with the
higher enlargement).

Perspective changes only with position, not lens focal length.
The fisheye case is not a change in perspective; it is a change
in image distortion.

There are many very knowledgeable, kind and helpful people
in this newsgroup. Please open your mind and try and
learn sometimes. It can be fun.

Roger
Anonymous
December 21, 2004 2:32:24 AM

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

Chris Brown <cpbrown@ntlworld.no_uce_please.com> wrote in
news:D 2kj92-jsn.ln1@narcissus.dyndns.org:

> In article <Xns95C56C115A22FLessThanPerfectInc@24.71.223.159>,
> Jon Pike <Anonomoose@spamlesshotmail.com> wrote:
>>
>>No, that's 100% wrong. When you change the focal length and retain the
>>field of view, you change perspective.
>
> Your understanding of optics is broken. Perspective is the relative
> apparent size of objects in a view. This varies based on their
> distance to the observer and nothing else.

Really?
I guess everyone can stop making fish-eye lenses then...

--
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Anonymous
December 21, 2004 2:32:55 AM

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

teflon <teflon@bluebottlefly.com> wrote in
news:BDECDA94.ED94%teflon@bluebottlefly.com:

> On 20/12/04 7:29 pm, in article d2kj92-jsn.ln1@narcissus.dyndns.org,
> "Chris Brown" <cpbrown@ntlworld.no_uce_please.com> wrote:
>
>> In article <Xns95C56C115A22FLessThanPerfectInc@24.71.223.159>,
>> Jon Pike <Anonomoose@spamlesshotmail.com> wrote:
>>>
>>> No, that's 100% wrong. When you change the focal length and retain
>>> the field of view, you change perspective.
>>
>> Your understanding of optics is broken. Perspective is the relative
>> apparent size of objects in a view. This varies based on their
>> distance to the observer and nothing else. The focal length of a lens
>> used to project an image at the observer's position has no effect on
>> this. For a given projection size, it simply varies the field of
>> view, leaving perspective unchanged.
>>
>> Perspective is a direct consequence of light traveling in straight
>> lines. The lens you mount on your camera will make no difference to
>> the path taken between the subject and the front lens element.
>
> He said when you "retain the field of view" - which means moving
> position.

Hey, look at that, someone noticed what I'm actually -typing-!

--
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Anonymous
December 21, 2004 2:34:42 AM

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

John Bean <john@waterfoot.net> wrote in
news:al9lvmo5bcwj.dlg@waterfoot.net:

> On Mon, 20 Dec 2004 19:37:15 GMT, teflon wrote:
>
>> On 20/12/04 7:29 pm, in article d2kj92-jsn.ln1@narcissus.dyndns.org,
>> "Chris Brown" <cpbrown@ntlworld.no_uce_please.com> wrote:
>>
>>> In article <Xns95C56C115A22FLessThanPerfectInc@24.71.223.159>,
>>> Jon Pike <Anonomoose@spamlesshotmail.com> wrote:
>>>>
>>>> No, that's 100% wrong. When you change the focal length and retain
>>>> the field of view, you change perspective.
>>>
>>> Your understanding of optics is broken. Perspective is the relative
>>> apparent size of objects in a view. This varies based on their
>>> distance to the observer and nothing else. The focal length of a
>>> lens used to project an image at the observer's position has no
>>> effect on this. For a given projection size, it simply varies the
>>> field of view, leaving perspective unchanged.
>>>
>>> Perspective is a direct consequence of light traveling in straight
>>> lines. The lens you mount on your camera will make no difference to
>>> the path taken between the subject and the front lens element.
>>
>> He said when you "retain the field of view" - which means moving
>> position.
>
> No, because the object image is a different size - smaller on the
> dSLR, so retaining the same position *and* field of view requires a
> different focal length. The perspective is unchanged.

No, that's wrong. The image projected by a 50mm lense will be the same size
regardless of using digital or film.
The PROBLEM with digital is that it doesn't -capture- the entire image. The
resulting "crop" (a bad use of the term) makes the object -seem- larger
when you enlarge it more !

Seems like you're the one who isn't understanding optics properly.

--
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Anonymous
December 21, 2004 2:35:44 AM

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

Chris Brown <cpbrown@ntlworld.no_uce_please.com> wrote in
news:sduj92-a6o.ln1@narcissus.dyndns.org:

> In article <BDECDA94.ED94%teflon@bluebottlefly.com>,
> teflon <teflon@bluebottlefly.com> wrote:
>>
>>He said when you "retain the field of view" - which means moving
>>position.
>
> No it doesn't. Field of view is the angle you can see through the
> lens, and is independent of where you stand.

It DOES change when you change focal lengths. So to -retain- the field of
view across different focal lengths, you have to move the camera. Doing so
affects perspective.


--
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Anonymous
December 21, 2004 2:40:37 AM

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

"Joseph Meehan" <sligojoe_Spamno@hotmail.com> wrote in
news:ffExd.4513$vb7.1271@fe1.columbus.rr.com:

> Jon Pike wrote:
>> Jim Redelfs <jim.redelfs@redelfs.com> wrote in
>> news:jim.redelfs-49F2C0.10150420122004@news.central.cox.net:
>>
>>> I just made the switch to a dSLR and am only now experiencing the
>>> similarities and, more importantly, the DISimilarities between
>>> digital and the film world I am leaving behind.
>>>
>>> I wish to acquire a lens for my new Canon 20D that will provide the
>>> same perspective as my old, reliable 50mm f1.4 attached to my AE1 or
>>> T90.
>>
>> Then get another 50mm f/1.4 lense. If you want the same
>> -perspective-, you get the same focal length.
>> If you want the same -field of view-, then you need a different
>> lense.
>>
>
> Sorry, but your advice is at best misleading. What you say is
> true IF
> the lens is used at the same distance. However most of the time a
> photographer will frame the subject and move closer or further away to
> archive the same coverage. Since the user of a 20D would need to move
> further way using the same lens as a full frame 35 mm the perspective
> would be different.

He asked specifically about perspetive. So I answered in accordance with
perspetive. I -also- spoke to the question of FOV.
It's up to him to frame the question properly, not to me to interpret it
(even though I did, just to be nice).
Saying silly things like "a 50mm lense on a digital with a crop of 1.6 is
like 80mm," now THAT is misleading. It doesn't tell the person anything
about what's -actually- going on.

> The use of a lens about 31 mm (28 or 35 should do nicely) would
> give the
> same coverage at the same distance and it would also give about the
> same perspective.

"about" the same perspective? From what distance?
Using a 31mm as opposed to a 50mm with the same FOV WILL change the
perspective.


--
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Anonymous
December 21, 2004 2:43:33 AM

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

Chris Brown <cpbrown@ntlworld.no_uce_please.com> wrote in
news:tsjj92-jsn.ln1@narcissus.dyndns.org:

> In article <Xns95C55F7937313LessThanPerfectInc@24.71.223.159>,
> Jon Pike <Anonomoose@spamlesshotmail.com> wrote:
>>
>>Then get another 50mm f/1.4 lense. If you want the same -perspective-,
>>you get the same focal length.
>
> No, if you want the same perspective, you stand in the same place to
> take the photograph. The required framing then dicatates the choice of
> lens.
>
> If you then want to frame the same subject in the same way with the
> same perspective, you need different lenses with a 20D than you do
> with a 35mm EOS. Given a 35mm EOS with a 50mm lens mounted, you will
> need a 20D with a 31mm focal length to get the same framing.

"in the same way" ?
Do you mean the same FOV or the same perspective?
You can get roughly the same FOV by changing lenses, but even THAT is not
exact, as shown by the background in the pictures here:
http://members.shaw.ca/anonomoose/perspective/

The main subject is the same size in all pictures (the sides of the
fountain touch the sides of the image), but the background changes
drastically from one picture to another.
So does the perspective.

--
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Anonymous
December 21, 2004 2:47:49 AM

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

Jim Redelfs <jim.redelfs@redelfs.com> wrote in news:jim.redelfs-
D1C5BC.15432920122004@news.central.cox.net:

> Am I to understand that these days, f2 is a fast-enough lens for indoor
> shooting without a flash?

f/2 isn't indicative of speed. that's a terrible misnomer.
Will f/2 let enough light through that I can shoot, hand-held, without a
flash, at _____iso?
The ISO speed you want to use is critical.
So too is your ability to hold a camera steady. I've seen some amazing
shots hand-held at 1/15. I've seen other people who can't hold a camera
steady to save their lives.

If you crank things up to 3200 iso you'll be able to use any lense you
want, because you can increase your shutter speed, and then not worry about
things looking fuzzy from camera movement.

If you're determined to use 50 iso, you're pretty much buggered no matter
what lense you use, because even an aperture of f/1 won't allow enough
light in (in most indoors situations) to let you hand-hold your camera at a
fast enough shutter speed.

--
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Anonymous
December 21, 2004 2:48:54 AM

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

Jim Redelfs <jim.redelfs@redelfs.com> wrote in news:jim.redelfs-
D1C5BC.15432920122004@news.central.cox.net:

> MANY moons ago I paid dearly to get the f1.4 lens instead of the more
> "standard" f1.8 for that extra ...what 1/3 (1/4?) stop?

1/2
which can be the difference between a shutter speed of 1/60 (which I'd
never try to hand-hold) and 1/90 (which I might, in a pinch).

--
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Anonymous
December 21, 2004 3:34:02 AM

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

>> Am I to understand that these days, f2 is a fast-enough lens for indoor
>> shooting without a flash?

>From: Jon Pike Anonomoose@spamlesshotmail.com
>
>f/2 isn't indicative of speed. that's a terrible misnomer.

Time for the killfile Jon ... plonk
Anonymous
December 21, 2004 4:08:30 AM

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

On 21/12/04 12:23 am, in article 10seqr6sd7vv029@news.supernews.com, "Jim
Townsend" <not@real.address> wrote:

> Jim Redelfs wrote:
>
>
>> MANY moons ago I paid dearly to get the f1.4 lens instead of the more
>> "standard" f1.8 for that extra ...what 1/3 (1/4?) stop?
>
> If you don't mind paying **dearly** again, Canon makes a 35mm f/1.4
> They go new for about $1200.00 US :-)
>
> As for using the f/2.0... With the low noise of the 20D, you can shoot at
> ISO 400-800 and get good results. The high ISOs should negate the loss of
> light if you choose the f/2.0 version... But if DOF is an important factor
> (for portrait work etc), you should go with the f/1.4

The depth of field difference between f/1.4 and f/2 on a 35mm is not very
practical in real terms, and certainly not worth paying the extra cost for.
Anonymous
December 21, 2004 4:08:31 AM

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

teflon wrote:

> On 21/12/04 12:23 am, in article 10seqr6sd7vv029@news.supernews.com, "Jim
> Townsend" <not@real.address> wrote:
>
>> Jim Redelfs wrote:
>>
>>
>>> MANY moons ago I paid dearly to get the f1.4 lens instead of the more
>>> "standard" f1.8 for that extra ...what 1/3 (1/4?) stop?
>>
>> If you don't mind paying **dearly** again, Canon makes a 35mm f/1.4
>> They go new for about $1200.00 US :-)
>>
>> As for using the f/2.0... With the low noise of the 20D, you can shoot at
>> ISO 400-800 and get good results. The high ISOs should negate the loss of
>> light if you choose the f/2.0 version... But if DOF is an important factor
>> (for portrait work etc), you should go with the f/1.4
>
> The depth of field difference between f/1.4 and f/2 on a 35mm is not very
> practical in real terms, and certainly not worth paying the extra cost for.

So who buys the 35mm f/1.4 lenses then. And why ;-)
Anonymous
December 21, 2004 5:58:17 AM

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

Jon Pike wrote:
> "Joseph Meehan" <sligojoe_Spamno@hotmail.com> wrote in
> news:bjExd.4539$vb7.4167@fe1.columbus.rr.com:
>
>> Jon Pike wrote:
>>> Chris Brown <cpbrown@ntlworld.no_uce_please.com> wrote in
>>> news:mqaj92-cin.ln1@narcissus.dyndns.org:
>>>
>>>> In article
>>>> <jim.redelfs-49F2C0.10150420122004@news.central.cox.net>, Jim
>>>> Redelfs <jim.redelfs@redelfs.com> wrote:
>>>>
>>>>> I wish to acquire a lens for my new Canon 20D that will provide
>>>>> the same perspective as my old, reliable 50mm f1.4 attached to my
>>>>> AE1 or T90.
>>>>>
>>>>> I wish to equip the camera for flashless work during a
>>>>> grandchild's birth. I used my AE1 and the above-mentioned lens
>>>>> for the flashless shoot of the baby's mother's birth. I'd like
>>>>> to send the proud father into the room with my camera equipped to
>>>>> do the best ambient shoot possible of my third grandchild.
>>>>
>>>> To get the same field of view (and therefore the same perspective
>>>> on th esame subject), you'll need something around a 28 or 35mm
>>>> lens. Canon do fast primes in both these lengths, but sadly
>>>> nothing as inexpensive as the 50mm f/1.8.
>>>
>>> No, that's 100% wrong. When you change the focal length and retain
>>> the field of view, you change perspective.
>>
>> Sorry Jon, when you change the focal length and retain the field
>> of
>> view, you don't change perspective. When you change the focal length
>> and retain the same distance, you change the perspective.
>
> Again, 100% wrong.
> Here's proof:
>
> http://members.shaw.ca/anonomoose/perspective/
>
> each picture is named for the length of the lense used to take it.
> See how the subject stays roughly the same, but the perspective
> changes a great deal?
> Images taken from:
> Camera and Lens - The Creative Approach
> by Ansel Adams
>
> My scanner doesn't do his images justice, but you -ought- to
> understand by now.

That the time to read the fine book by Adams and read it carefully with
an open mind. Then maybe you will understand what is going on here and why
what you are saying is just wrong.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math
Anonymous
December 21, 2004 5:59:45 AM

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

Jon Pike wrote:
> "Joseph Meehan" <sligojoe_Spamno@hotmail.com> wrote in
> news:ffExd.4513$vb7.1271@fe1.columbus.rr.com:
>
>> Jon Pike wrote:
>>> Jim Redelfs <jim.redelfs@redelfs.com> wrote in
>>> news:jim.redelfs-49F2C0.10150420122004@news.central.cox.net:
>>>
>>>> I just made the switch to a dSLR and am only now experiencing the
>>>> similarities and, more importantly, the DISimilarities between
>>>> digital and the film world I am leaving behind.
>>>>
>>>> I wish to acquire a lens for my new Canon 20D that will provide the
>>>> same perspective as my old, reliable 50mm f1.4 attached to my AE1
>>>> or T90.
>>>
>>> Then get another 50mm f/1.4 lense. If you want the same
>>> -perspective-, you get the same focal length.
>>> If you want the same -field of view-, then you need a different
>>> lense.
>>>
>>
>> Sorry, but your advice is at best misleading. What you say is
>> true IF
>> the lens is used at the same distance. However most of the time a
>> photographer will frame the subject and move closer or further away
>> to archive the same coverage. Since the user of a 20D would need to
>> move further way using the same lens as a full frame 35 mm the
>> perspective would be different.
>
> He asked specifically about perspetive. So I answered in accordance
> with perspetive. I -also- spoke to the question of FOV.
> It's up to him to frame the question properly, not to me to interpret
> it (even though I did, just to be nice).
> Saying silly things like "a 50mm lense on a digital with a crop of
> 1.6 is like 80mm," now THAT is misleading. It doesn't tell the person
> anything about what's -actually- going on.
>
>> The use of a lens about 31 mm (28 or 35 should do nicely) would
>> give the
>> same coverage at the same distance and it would also give about the
>> same perspective.
>
> "about" the same perspective? From what distance?
> Using a 31mm as opposed to a 50mm with the same FOV WILL change the
> perspective.

Sorry the advice you gave was both wrong and misleading based on the
original question. You need to open your mind and relearn what you think
you know. You just don't have it right in your head. Sorry.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math
Anonymous
December 21, 2004 6:04:29 AM

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

Jon Pike wrote:
> bob <Jwx1.nothing@bellsouth.net> wrote in
> news:Xns95C58B9A44422j123w123x123@216.77.188.18:
>
>> Jon Pike <Anonomoose@spamlesshotmail.com> wrote in
>> news:Xns95C56C115A22FLessThanPerfectInc@24.71.223.159:
>>
>>> No, that's 100% wrong. When you change the focal length and retain
>>> the field of view, you change perspective.
>>>
>>
>> You are mistaken. Perspective refers to relative size and position of
>> objects in the picture. It is determined entirely by lens position
>> and the direction the lens is pointed in.
>>
>> If you set your camera on a tripod, and take photos with every lens
>> you own, then all the resulting photos will have the same
>> perspective, excepting the minor variations in lens nodal point.
>
> If that were the case, then how do you explain the pictures I posted
> here? http://members.shaw.ca/anonomoose/perspective/
>
> The subject, and field of view stay as much the same as possible, but
> the use of longer lense changes the perspective.
> Pay special attention to the two little "stumps" in the foreground.

No argument with that. But that is was not the question at issue. You
did not change the size of the recorded image (full frame 35 mm v.s. a 1.6
sensor is not the same). The size of the media be it film in a minox or a
20x24 glass plate (and I have used both) makes a big difference and it is a
factor you want to totally ignore.


--
Joseph Meehan

26 + 6 = 1 It's Irish Math
Anonymous
December 21, 2004 6:05:56 AM

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

Jon Pike wrote:
> John Bean <john@waterfoot.net> wrote in
> news:al9lvmo5bcwj.dlg@waterfoot.net:
>
>> On Mon, 20 Dec 2004 19:37:15 GMT, teflon wrote:
>>
>>> On 20/12/04 7:29 pm, in article d2kj92-jsn.ln1@narcissus.dyndns.org,
>>> "Chris Brown" <cpbrown@ntlworld.no_uce_please.com> wrote:
>>>
>>>> In article <Xns95C56C115A22FLessThanPerfectInc@24.71.223.159>,
>>>> Jon Pike <Anonomoose@spamlesshotmail.com> wrote:
>>>>>
>>>>> No, that's 100% wrong. When you change the focal length and retain
>>>>> the field of view, you change perspective.
>>>>
>>>> Your understanding of optics is broken. Perspective is the relative
>>>> apparent size of objects in a view. This varies based on their
>>>> distance to the observer and nothing else. The focal length of a
>>>> lens used to project an image at the observer's position has no
>>>> effect on this. For a given projection size, it simply varies the
>>>> field of view, leaving perspective unchanged.
>>>>
>>>> Perspective is a direct consequence of light traveling in straight
>>>> lines. The lens you mount on your camera will make no difference to
>>>> the path taken between the subject and the front lens element.
>>>
>>> He said when you "retain the field of view" - which means moving
>>> position.
>>
>> No, because the object image is a different size - smaller on the
>> dSLR, so retaining the same position *and* field of view requires a
>> different focal length. The perspective is unchanged.
>
> No, that's wrong. The image projected by a 50mm lense will be the
> same size regardless of using digital or film.
> The PROBLEM with digital is that it doesn't -capture- the entire
> image. The resulting "crop" (a bad use of the term) makes the object
> -seem- larger when you enlarge it more !

You are hung up on this to the point of not being able to see the truth.
The captured image is different and YOU are tying to ignore it.

>
> Seems like you're the one who isn't understanding optics properly.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math
Anonymous
December 21, 2004 7:38:43 AM

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

bhilton665@aol.comedy (Bill Hilton) wrote in
news:20041220193402.06125.00001437@mb-m23.aol.com:

>>> Am I to understand that these days, f2 is a fast-enough lens for
>>> indoor shooting without a flash?
>
>>From: Jon Pike Anonomoose@spamlesshotmail.com
>>
>>f/2 isn't indicative of speed. that's a terrible misnomer.
>
> Time for the killfile Jon ... plonk

For stating a perfectly accurate fact?
Guess that indicates to me how much a loss I ought to feel about his
contributions...

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Anonymous
December 21, 2004 7:43:12 AM

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

"Joseph Meehan" <sligojoe_Spamno@hotmail.com> wrote in
news:D jMxd.3865$mA3.1666@fe2.columbus.rr.com:

>>> Sorry Jon, when you change the focal length and retain the field
>>> of
>>> view, you don't change perspective. When you change the focal
>>> length and retain the same distance, you change the perspective.
>>
>> Again, 100% wrong.
>> Here's proof:
>>
>> http://members.shaw.ca/anonomoose/perspective/
>>
>> each picture is named for the length of the lense used to take it.
>> See how the subject stays roughly the same, but the perspective
>> changes a great deal?
>> Images taken from:
>> Camera and Lens - The Creative Approach
>> by Ansel Adams
>>
>> My scanner doesn't do his images justice, but you -ought- to
>> understand by now.
>
> That the time to read the fine book by Adams and read it carefully
> with
> an open mind. Then maybe you will understand what is going on here
> and why what you are saying is just wrong.

If you think I'm so wrong, why don't you explain it, clearly, and with
supporting facts?
Or are you content to follow Roger's example, tell me I'm wrong, and then
provide no support whatsoever?

It seems to me that you've got "FOV" and "perspective" backwards.
FOV is the area you see. Quite literally; "field of view"
This changes -drastically- when you remain in the same position, but
change focal lengths. That's the whole POINT of a zoom lense!
You seem to have it 100% backwards, because you state exactly the
opposite.

Maybe a trip to google to look up what the two terms mean might help you
understand things clearer?

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Anonymous
December 21, 2004 7:44:14 AM

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

"Joseph Meehan" <sligojoe_Spamno@hotmail.com> wrote in
news:BkMxd.3868$mA3.2653@fe2.columbus.rr.com:

> Jon Pike wrote:
>> "Joseph Meehan" <sligojoe_Spamno@hotmail.com> wrote in
>> news:ffExd.4513$vb7.1271@fe1.columbus.rr.com:
>>
>>> Jon Pike wrote:
>>>> Jim Redelfs <jim.redelfs@redelfs.com> wrote in
>>>> news:jim.redelfs-49F2C0.10150420122004@news.central.cox.net:
>>>>
>>>>> I just made the switch to a dSLR and am only now experiencing the
>>>>> similarities and, more importantly, the DISimilarities between
>>>>> digital and the film world I am leaving behind.
>>>>>
>>>>> I wish to acquire a lens for my new Canon 20D that will provide
>>>>> the same perspective as my old, reliable 50mm f1.4 attached to my
>>>>> AE1 or T90.
>>>>
>>>> Then get another 50mm f/1.4 lense. If you want the same
>>>> -perspective-, you get the same focal length.
>>>> If you want the same -field of view-, then you need a different
>>>> lense.
>>>>
>>>
>>> Sorry, but your advice is at best misleading. What you say is
>>> true IF
>>> the lens is used at the same distance. However most of the time a
>>> photographer will frame the subject and move closer or further away
>>> to archive the same coverage. Since the user of a 20D would need to
>>> move further way using the same lens as a full frame 35 mm the
>>> perspective would be different.
>>
>> He asked specifically about perspetive. So I answered in accordance
>> with perspetive. I -also- spoke to the question of FOV.
>> It's up to him to frame the question properly, not to me to interpret
>> it (even though I did, just to be nice).
>> Saying silly things like "a 50mm lense on a digital with a crop of
>> 1.6 is like 80mm," now THAT is misleading. It doesn't tell the person
>> anything about what's -actually- going on.
>>
>>> The use of a lens about 31 mm (28 or 35 should do nicely) would
>>> give the
>>> same coverage at the same distance and it would also give about the
>>> same perspective.
>>
>> "about" the same perspective? From what distance?
>> Using a 31mm as opposed to a 50mm with the same FOV WILL change the
>> perspective.
>
> Sorry the advice you gave was both wrong and misleading based on
> the
> original question. You need to open your mind and relearn what you
> think you know. You just don't have it right in your head. Sorry.

Really?
The prove me wrong. You're using wishy-washy vague language and providing
no support whatsoever for anything you're (not) saying.

If you don't provide some substance, you'll just prove yourself a troll.

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Anonymous
December 21, 2004 7:45:51 AM

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

"Joseph Meehan" <sligojoe_Spamno@hotmail.com> wrote in
news:1pMxd.3869$mA3.2707@fe2.columbus.rr.com:

> Jon Pike wrote:
>> bob <Jwx1.nothing@bellsouth.net> wrote in
>> news:Xns95C58B9A44422j123w123x123@216.77.188.18:
>>
>>> Jon Pike <Anonomoose@spamlesshotmail.com> wrote in
>>> news:Xns95C56C115A22FLessThanPerfectInc@24.71.223.159:
>>>
>>>> No, that's 100% wrong. When you change the focal length and retain
>>>> the field of view, you change perspective.
>>>>
>>>
>>> You are mistaken. Perspective refers to relative size and position
>>> of objects in the picture. It is determined entirely by lens
>>> position and the direction the lens is pointed in.
>>>
>>> If you set your camera on a tripod, and take photos with every lens
>>> you own, then all the resulting photos will have the same
>>> perspective, excepting the minor variations in lens nodal point.
>>
>> If that were the case, then how do you explain the pictures I posted
>> here? http://members.shaw.ca/anonomoose/perspective/
>>
>> The subject, and field of view stay as much the same as possible, but
>> the use of longer lense changes the perspective.
>> Pay special attention to the two little "stumps" in the foreground.
>
> No argument with that. But that is was not the question at issue.
> You
> did not change the size of the recorded image (full frame 35 mm v.s. a
> 1.6 sensor is not the same). The size of the media be it film in a
> minox or a 20x24 glass plate (and I have used both) makes a big
> difference and it is a factor you want to totally ignore.

The image transmitted to the media by the lense does NOT change with the
media you choose to use.
That's a plain and simple fact you seem unable to grasp.
Enlarging something in post-production is NOT at ALL related to changing
your focal length -before- you even take the image.

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Anonymous
December 21, 2004 7:50:10 AM

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

Florian <petafrog@evilemail.com> wrote in
news:m3pt14cmvm.fsf@tiainen.domain.invalid:

> Jon Pike <Anonomoose@spamlesshotmail.com> writes:
>
>> "Joseph Meehan" <sligojoe_Spamno@hotmail.com> wrote in
>> news:bjExd.4539$vb7.4167@fe1.columbus.rr.com:
>>
>> > Jon Pike wrote:
>
> (snip)
>
>> >> No, that's 100% wrong. When you change the focal length and retain
>> >> the field of view, you change perspective.
>> >
>> > Sorry Jon, when you change the focal length and retain the field of
>> > view, you don't change perspective. When you change the focal
>> > length and retain the same distance, you change the perspective.
>>
>> Again, 100% wrong.
>> Here's proof:
>>
>> http://members.shaw.ca/anonomoose/perspective/
>>
>> each picture is named for the length of the lense used to take it.
>> See how the subject stays roughly the same, but the perspective
>> changes a great deal?
>> Images taken from:
>> Camera and Lens - The Creative Approach
>> by Ansel Adams
>>
>> My scanner doesn't do his images justice, but you -ought- to
>> understand by now.
>
> Uh... what exactly, in your humble opinion, is happening to the field
> of view in those pictures when you go from 40mm to 250mm? Do you
> really think each picture was shot from the same distance?

No, I didn't say they were shot at the same distance at all.
Did I say that anywhere?
Did I hint, anywhere, that I'm talking about shooting at the same
distance?
The correct answer is: "No."

The field of view is staying as similar as perspective allows it to. In
each image the edges of the fountain meet with the edges of the image.
The camera is moved back to achieve this as different lenses were used.
The camera remained at the same height for all pictures.
The FOV remains the same, the perspective changes.

Conversely, if you were to change lenses as dumb people suggest when
using digicams, you would change the FOV. It really shouldn't take a
whole lot of grey-matter to figure that out.

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!