Sign in with
Sign up | Sign in
Your question

The problem of SLR lenses on DSLRs

Last response: in Digital Camera
Share
September 11, 2005 7:37:09 AM

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

Rich <none@none.com> wrote in news:vdq6i1dnj06tla1n39sqph23hno779ikvi@
4ax.com:

> Note the vignetting in this image.
>
> http://web.canon.jp/Imaging/cmos/shootingoption-e/outdo...

Ummm, I can't find the comparison images with the same lens and same
settings but with a film SLR. So the evidence that suggests that the
problem is because the camera is a D-SLR using a lens designed for a film
SLR is what?


--
Mark Heyes (New Zealand)
See my pics at www.gigatech.co.nz (last updated 5-September-05)
"The person on the other side was a young woman. Very obviously a
young woman. There was no possible way she could have been mistaken
for a young man in any language, especially Braille."
Maskerade
Anonymous
September 11, 2005 12:46:22 PM

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

In article <FDNUe.412653$WN5.117382@fe02.news.easynews.com>,
MarkH <markat@atdot.dot.dot> wrote:
>Rich <none@none.com> wrote in news:vdq6i1dnj06tla1n39sqph23hno779ikvi@
>4ax.com:
>
>> Note the vignetting in this image.
>>
>> http://web.canon.jp/Imaging/cmos/shootingoption-e/outdo...
>
>Ummm, I can't find the comparison images with the same lens and same
>settings but with a film SLR. So the evidence that suggests that the
>problem is because the camera is a D-SLR using a lens designed for a film
>SLR is what?

What is more interesting, is that if you want the same DoF and field of view
on an 1.5x APS-C dSLR, you need a 33/0.93.

I'm not aware of any 35/1.0 lenses. So you simply can't take this shot with
an APS-C sensor.


--
That was it. Done. The faulty Monk was turned out into the desert where it
could believe what it liked, including the idea that it had been hard done
by. It was allowed to keep its horse, since horses were so cheap to make.
-- Douglas Adams in Dirk Gently's Holistic Detective Agency
Related resources
Anonymous
September 11, 2005 1:44:05 PM

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

"Rich" <none@none.com> wrote in message
news:vdq6i1dnj06tla1n39sqph23hno779ikvi@4ax.com...
> Note the vignetting in this image.
>
> http://web.canon.jp/Imaging/cmos/shootingoption-e/outdo...

Ummmm...
Is someone getting something backwards here?

--
Jeff R.
Anonymous
September 11, 2005 4:15:21 PM

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

Rich wrote:
>
> Note the vignetting in this image.
>
> http://web.canon.jp/Imaging/cmos/shootingoption-e/outdo...

Sod me, Rich, you're beyond any help.

One: The bloody lens was wide open. ANY lens wide open will vignette
to some degree. Even non-Canon ones (horror!)

Two: despite the write-up, the image was shot indoors. Any schoolboy
will tell you that the upper walls and ceiling have less illumination
than lower down. High areas in a room are lit only by reflection from
the floor and furniture. This is shown by the lower corners of the
image not being 'vignetted' to the same degree as the upper corners.

Three: Post processing may well have included darkening the top corners
- a well respected practice to focus attention on the subject and
prevent the eye from wandering out of the picture. Practically a
*requirement* for good portraiture.

In short, you are clearly ignorant about photography in general, and you
do yourself a major disservice every time you open your very large mouth
about things you have no grasp of.

Conclusion: You're just a troll who has managed to jerk two reactions
from me today. Congratulations. Laugh yourself sick.

Colin D.

PS: Part of the reason behind my reactive answers is to try to undo the
harm you are doing to posters or lurkers who may be tempted to believe
your irrational outbursts.
September 11, 2005 4:15:22 PM

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

On Sun, 11 Sep 2005 12:15:21 +1200, Colin D
<ColinD@killspam.127.0.0.1> wrote:

>
>
>Rich wrote:
>>
>> Note the vignetting in this image.
>>
>> http://web.canon.jp/Imaging/cmos/shootingoption-e/outdo...
>
>Sod me, Rich, you're beyond any help.
>
>One: The bloody lens was wide open. ANY lens wide open will vignette
>to some degree. Even non-Canon ones (horror!)

Vignetting is a consequence of using 35mm lenses (because the light
>
>Two: despite the write-up, the image was shot indoors. Any schoolboy
>will tell you that the upper walls and ceiling have less illumination
>than lower down. High areas in a room are lit only by reflection from
>the floor and furniture. This is shown by the lower corners of the
>image not being 'vignetted' to the same degree as the upper corners.
>
>Three: Post processing may well have included darkening the top corners
>- a well respected practice to focus attention on the subject and
>prevent the eye from wandering out of the picture. Practically a
>*requirement* for good portraiture.
>
>In short, you are clearly ignorant about photography in general, and you
>do yourself a major disservice every time you open your very large mouth
>about things you have no grasp of.
>
>Conclusion: You're just a troll who has managed to jerk two reactions
>from me today. Congratulations. Laugh yourself sick.
>
>Colin D.
>
>PS: Part of the reason behind my reactive answers is to try to undo the
>harm you are doing to posters or lurkers who may be tempted to believe
>your irrational outbursts.

The most obvious conclusion is that the lens vignetted, not the
convoluted "path" you suggested was the cause of what you see in that
image. Vignetting is one of the failings you see when 35mm FILM
lenses are used on digital cameras. This was all explained when the
4/3 system was devised, too bad you didn't read about it.
-Rich
Anonymous
September 11, 2005 7:35:43 PM

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

"Rich" <none@none.com> wrote in message
news:vdq6i1dnj06tla1n39sqph23hno779ikvi@4ax.com...
> Note the vignetting in this image.
>
> http://web.canon.jp/Imaging/cmos/shootingoption-e/outdo...

Any idea how that lens would vignet on film???

Good sensor arrays use microlenses. Those microlenses are probably
more efficient in concentrating the oblique incident light on the
photosensitive surface than film without microlenses is. The fact that
light has to travel further to reach the corners remains.

Bart
Anonymous
September 11, 2005 11:30:23 PM

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

"Rich" <none@none.com> wrote in message
news:4637i1dc6f7gaqtk3f8giaiaasl5bn5heg@4ax.com...
SNIP
> Vignetting is one of the failings you see when 35mm FILM
> lenses are used on digital cameras.

Is it? I've yet to see quantitative proof.

In fact, in competent designs (with microlenses) a FF-sensor array
like this 1Ds Mark II with the EF 50mm f/1.4 shot at f/8.0 is quite
well behaved:
<http://www.xs4all.nl/~bvdwolf/main/foto/Imatest/Vignett...;
, and I'd be surprised to see much different results from film.

Bart
September 11, 2005 11:30:24 PM

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

On Sun, 11 Sep 2005 19:30:23 +0200, "Bart van der Wolf"
<bvdwolf@no.spam> wrote:

>
>"Rich" <none@none.com> wrote in message
>news:4637i1dc6f7gaqtk3f8giaiaasl5bn5heg@4ax.com...
>SNIP
>> Vignetting is one of the failings you see when 35mm FILM
>> lenses are used on digital cameras.
>
>Is it? I've yet to see quantitative proof.
>
>In fact, in competent designs (with microlenses) a FF-sensor array
>like this 1Ds Mark II with the EF 50mm f/1.4 shot at f/8.0 is quite
>well behaved:
><http://www.xs4all.nl/~bvdwolf/main/foto/Imatest/Vignett...;
>, and I'd be surprised to see much different results from film.
>
>Bart

It only stands to reason. If what the other poster says is correct,
that wide open that lens will vignette with film, then because the
light rays coming from the edge of the lens are highly oblique, the
vignetting would exist unless the lens was physically much larger than
it actually is (so you'd only be using the centre of the lens to form
the image instead of the whole aperture). If vignetting is made worse
when using a sensor instead of film and if the lens already displays
vignetting with film when wide open, then it's reasonable to assume
that the edge darkening shown in the picture (gross as it was) was
vignetting and was so severe only cropping (and not adjusting the
illumination levels in software) would be needed with the image.
Many of the "add-on" tele and WA attachments for P&S cameras exhibit
this problem. Talk of using "f8" really makes no sense in the context
of that image since the goal was a blurred background, as DSLR owners
constantly point out is one of the benefits of DSLRs against P&S
cameras, for portrait work.
-Rich
Anonymous
September 11, 2005 11:35:26 PM

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

"MarkH" <markat@atdot.dot.dot> wrote in message
news:FDNUe.412653$WN5.117382@fe02.news.easynews.com...
> Rich <none@none.com> wrote in
> news:vdq6i1dnj06tla1n39sqph23hno779ikvi@
> 4ax.com:
>
>> Note the vignetting in this image.
>>
>> http://web.canon.jp/Imaging/cmos/shootingoption-e/outdo...
>
> Ummm, I can't find the comparison images with the same lens and
> same settings but with a film SLR. So the evidence that suggests
> that the problem is because the camera is a D-SLR using a lens
> designed for a film SLR is what?

Exactly, unsubstantiated speculation (at best)!

In fact, even with just a DSLR (EOS 1Ds Mark II in this case) it is
trivial (with the right evaluation tools) to demonstrate that lens
design and aperture have a dominant influence on light fall-off (just
like with film):
<http://www.xs4all.nl/~bvdwolf/main/foto/Imatest/Vignett...;

Although a nice experiment for the future, the light fall-off at f/8.0
is so small that I won't even bother to waste a film on it to
demonstrate what the effect of film surface reflection has, compared
to the micro-lenses on a good FF-sensor array:
<http://www.xs4all.nl/~bvdwolf/main/foto/Imatest/Vignett...;
The microlenses almost guarantee a perfect angle of incidence.

Bart
September 11, 2005 11:35:27 PM

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

On Sun, 11 Sep 2005 19:35:26 +0200, "Bart van der Wolf"
<bvdwolf@no.spam> wrote:

>
>"MarkH" <markat@atdot.dot.dot> wrote in message
>news:FDNUe.412653$WN5.117382@fe02.news.easynews.com...
>> Rich <none@none.com> wrote in
>> news:vdq6i1dnj06tla1n39sqph23hno779ikvi@
>> 4ax.com:
>>
>>> Note the vignetting in this image.
>>>
>>> http://web.canon.jp/Imaging/cmos/shootingoption-e/outdo...
>>
>> Ummm, I can't find the comparison images with the same lens and
>> same settings but with a film SLR. So the evidence that suggests
>> that the problem is because the camera is a D-SLR using a lens
>> designed for a film SLR is what?
>
>Exactly, unsubstantiated speculation (at best)!
>
>In fact, even with just a DSLR (EOS 1Ds Mark II in this case) it is
>trivial (with the right evaluation tools) to demonstrate that lens
>design and aperture have a dominant influence on light fall-off (just
>like with film):
><http://www.xs4all.nl/~bvdwolf/main/foto/Imatest/Vignett...;
>
>Although a nice experiment for the future, the light fall-off at f/8.0
>is so small that I won't even bother to waste a film on it to
>demonstrate what the effect of film surface reflection has, compared
>to the micro-lenses on a good FF-sensor array:
><http://www.xs4all.nl/~bvdwolf/main/foto/Imatest/Vignett...;
>The microlenses almost guarantee a perfect angle of incidence.
>
>Bart

Don't the microlenses actually increase the angle of incidence of the
light beam as it goes through them? Unless of course physics has been
suspended and the microlenses display negative refraction?
-Rich
Anonymous
September 11, 2005 11:50:34 PM

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

"Rich" <none@none.com> wrote in message
news:vdq6i1dnj06tla1n39sqph23hno779ikvi@4ax.com...
> Note the vignetting in this image.
>
> http://web.canon.jp/Imaging/cmos/shootingoption-e/outdo...

The only vignetting I see is not vignetting but the way the image was lit.
Except for the kit lens, I use all 35mm lenses on my D70, and I've never had
any problems with vignetting, at least that I or anybody else can see.
September 12, 2005 4:42:01 AM

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

On Sun, 11 Sep 2005 19:50:34 -0600, "Sheldon"
<sheldon@XXXXXXXXsopris.net> wrote:

>
>"Rich" <none@none.com> wrote in message
>news:vdq6i1dnj06tla1n39sqph23hno779ikvi@4ax.com...
>> Note the vignetting in this image.
>>
>> http://web.canon.jp/Imaging/cmos/shootingoption-e/outdo...
>
>The only vignetting I see is not vignetting but the way the image was lit.
>Except for the kit lens, I use all 35mm lenses on my D70, and I've never had
>any problems with vignetting, at least that I or anybody else can see.
>

That's a 1.5 sensor, the lenses more than cover it so it's not an
issue I guess. A full frame however might be different.
If a lens open at f1.4 vignetting with 35mm film, then for sure it
will with a full-frame sensor.
-Rich
Anonymous
September 12, 2005 4:49:28 AM

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

"Rich" <none@none.com> wrote in message
news:q139i1dp25rskj61511gmnpmv2b9g313lp@4ax.com...
> On Sun, 11 Sep 2005 19:30:23 +0200, "Bart van der Wolf"
> <bvdwolf@no.spam> wrote:
SNIP
>> in competent designs (with microlenses) a FF-sensor
>> array like this 1Ds Mark II with the EF 50mm f/1.4 shot
>> at f/8.0 is quite well behaved:
>> <http://www.xs4all.nl/~bvdwolf/main/foto/Imatest/Vignett...;
>> , and I'd be surprised to see much different results from
>> film.
[...]
> It only stands to reason. If what the other poster says is
> correct, that wide open that lens will vignette with film,

Yes, most lenses will vignet more when wide open than when stopped
down, no different for the f/1.4 although the geometics of the design
will cause an f/1.4 vignet more likely than e.g. an f/2.8 or smaller.

> then because the light rays coming from the edge of the lens
> are highly oblique, the vignetting would exist unless the lens
> was physically much larger than it actually is (so you'd only
> be using the centre of the lens to form the image instead of
> the whole aperture).

That's not really what happens. I think the reasoning flaw can be
explained from a too simple mental diagram of ray propagation through
a lens. The light entering the lens should be envisioned as a cone of
light emanating from each point of the original scene as seen by the
entrance pupil of the lens. That cone will travel through the lens,
its diameter will then be restricted by the aperture and will leave
the lens at an apparent exit pupil, still as a 'cone' of light.

The cone of light, which may look like an elliptical (due to looking
through a tube from an angle) cone of light will also have to travel
farther to the corners of the flat plane of projection than to the
center of the projection plane (rectilinear design).

The result for the EF 50mm f/1.4 lens for the 4 largest full stops
looks like this:
<http://www.xs4all.nl/~bvdwolf/main/foto/Imatest/Vignett...;
.. Mind you that's all on the same sensor, with only the corner ellipse
of light turning into more of a cone of light, but still traveling a
longer distance to the corners (so some loss is inevitable).

> If vignetting is made worse when using a sensor instead of film

No, it would mostly have to be caused by surface reflection
characteristics by part of the light ellipse, but it's
reduced/eliminated by microlenses as present on the sensor array
tested above (but not on film).

> and if the lens already displays vignetting with film when wide
> open,

Yes, as explained above.

> then it's reasonable to assume that the edge darkening shown
> in the picture (gross as it was) was vignetting

Mostly lens vignetting, nothing to do with the sensor yet! Try looking
through a detached lens as you move your eye off-axis. If the exit
pupil turns into an ellipse, the lens will vignet.

> and was so severe only cropping (and not adjusting the
> illumination levels in software) would be needed with the image.

Vignetting adjustment in software is very useful if needed, and the
relative under-exposure of the corners re-enforces the "expose to the
right" axiom for RAW capture. Cropping is not necessary under most
circumstances. The excellent higher ISO performance often allows to
stop down a little.

> Many of the "add-on" tele and WA attachments for P&S
> cameras exhibit this problem. Talk of using "f8" really
> makes no sense in the context of that image since the
> goal was a blurred background, as DSLR owners
> constantly point out is one of the benefits of DSLRs
> against P&S cameras, for portrait work.

f/8 is relevant to demonstrate that it is mostly the lens that
vignettes at larger apertures, not the sensor.

Bart
Anonymous
September 12, 2005 4:52:44 AM

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

"Rich" <none@none.com> wrote in message
news:rs29i1peggfoara0d766itk7oohbi4vqqv@4ax.com...
SNIP
> Don't the microlenses actually increase the angle of incidence
> of the light beam as it goes through them?

No, the polymers slow down the light (refractive index > 1.0) and thus
behave as condensors/lenses.

Bart
Anonymous
September 12, 2005 6:46:34 AM

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

"Rich" <none@none.com> wrote in message
news:D m1ai11uaq7l85teo1p51a4h2njutiuiag@4ax.com...
> On Sun, 11 Sep 2005 19:50:34 -0600, "Sheldon"
> <sheldon@XXXXXXXXsopris.net> wrote:
>
>>
>>"Rich" <none@none.com> wrote in message
>>news:vdq6i1dnj06tla1n39sqph23hno779ikvi@4ax.com...
>>> Note the vignetting in this image.
>>>
>>> http://web.canon.jp/Imaging/cmos/shootingoption-e/outdo...
>>
>>The only vignetting I see is not vignetting but the way the image was lit.
>>Except for the kit lens, I use all 35mm lenses on my D70, and I've never
>>had
>>any problems with vignetting, at least that I or anybody else can see.
>>
>
> That's a 1.5 sensor, the lenses more than cover it so it's not an
> issue I guess. A full frame however might be different.
> If a lens open at f1.4 vignetting with 35mm film, then for sure it
> will with a full-frame sensor.
> -Rich

Yes, but, Rich, your original implication was that 35mm film lenses would
vignette on digital cameras (FF) BECAUSE they were used on digital cameras.
To wit: "Vignetting is one of the failings you see when 35mm FILM lenses are
used on digital cameras." Since the 50mm 1.4 doesn't vignette on film, I
certainly wouldn't expect it to vignette on digital, and the image you
posted doesn't show any vignetting, only light variations on the background.

--
Skip Middleton
http://www.shadowcatcherimagery.com
Anonymous
September 12, 2005 9:47:55 AM

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

On Mon, 12 Sep 2005 00:42:01 -0400, in rec.photo.digital.slr-systems Rich
<none@none.com> wrote:

>If a lens open at f1.4 vignetting with 35mm film, then for sure it
>will with a full-frame sensor.

That is tautologically correct, so then your point is? Changing the sensor
the image is projected upon doesn't change the optical properties of the
lens.
----------
Ed Ruf Lifetime AMA# 344007 (Usenet@EdwardG.Ruf.com)
See images taken with my CP-990/5700 & D70 at
http://edwardgruf.com/Digital_Photography/General/index...
Anonymous
September 12, 2005 12:46:49 PM

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

"Rich" <none@none.com> wrote in message
news:4637i1dc6f7gaqtk3f8giaiaasl5bn5heg@4ax.com...
> On Sun, 11 Sep 2005 12:15:21 +1200, Colin D
> <ColinD@killspam.127.0.0.1> wrote:
>
>>
>>
>>Rich wrote:
>>>
>>> Note the vignetting in this image.
>>>
>>> http://web.canon.jp/Imaging/cmos/shootingoption-e/outdo...
>>
>>Sod me, Rich, you're beyond any help.
>>
>>One: The bloody lens was wide open. ANY lens wide open will vignette
>>to some degree. Even non-Canon ones (horror!)
>
> Vignetting is a consequence of using 35mm lenses (because the light
>>
>>Two: despite the write-up, the image was shot indoors. Any schoolboy
>>will tell you that the upper walls and ceiling have less illumination
>>than lower down. High areas in a room are lit only by reflection from
>>the floor and furniture. This is shown by the lower corners of the
>>image not being 'vignetted' to the same degree as the upper corners.
>>
>>Three: Post processing may well have included darkening the top corners
>>- a well respected practice to focus attention on the subject and
>>prevent the eye from wandering out of the picture. Practically a
>>*requirement* for good portraiture.
>>
>>In short, you are clearly ignorant about photography in general, and you
>>do yourself a major disservice every time you open your very large mouth
>>about things you have no grasp of.
>>
>>Conclusion: You're just a troll who has managed to jerk two reactions
>>from me today. Congratulations. Laugh yourself sick.
>>
>>Colin D.
>>
>>PS: Part of the reason behind my reactive answers is to try to undo the
>>harm you are doing to posters or lurkers who may be tempted to believe
>>your irrational outbursts.
>
> The most obvious conclusion is that the lens vignetted, not the
> convoluted "path" you suggested was the cause of what you see in that
> image. Vignetting is one of the failings you see when 35mm FILM
> lenses are used on digital cameras. This was all explained when the
> 4/3 system was devised, too bad you didn't read about it.
> -Rich


Please stop posting bollox - Olympus claim that their lenses are 'designed
for digital', yet many vignette so badly Olympus had to include 'shading
compensation' on their DSLR's

I know for a fact that the 14-45, 40-150 and the 14-54 Zuiko lenses have a
vignetting problem - so please stop pissing about with your puerile
trolling - you're clearly in need of an obliging woman to take your mind off
these forums.
September 12, 2005 8:58:22 PM

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

"Since the 50mm 1.4 doesn't vignette on film, I
certainly wouldn't expect it to vignette on digital, and the image you
posted doesn't show any vignetting, only light variations on the
background. "

The final illumination falloff you see in an image is a combination of
factors, including cos^4 effects, optical vignetting, and sensor
vignetting.
September 13, 2005 12:32:44 AM

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

On Mon, 12 Sep 2005 02:46:34 -0700, "Skip M" <shadowcatcher@cox.net>
wrote:

>"Rich" <none@none.com> wrote in message
>news:D m1ai11uaq7l85teo1p51a4h2njutiuiag@4ax.com...
>> On Sun, 11 Sep 2005 19:50:34 -0600, "Sheldon"
>> <sheldon@XXXXXXXXsopris.net> wrote:
>>
>>>
>>>"Rich" <none@none.com> wrote in message
>>>news:vdq6i1dnj06tla1n39sqph23hno779ikvi@4ax.com...
>>>> Note the vignetting in this image.
>>>>
>>>> http://web.canon.jp/Imaging/cmos/shootingoption-e/outdo...
>>>
>>>The only vignetting I see is not vignetting but the way the image was lit.
>>>Except for the kit lens, I use all 35mm lenses on my D70, and I've never
>>>had
>>>any problems with vignetting, at least that I or anybody else can see.
>>>
>>
>> That's a 1.5 sensor, the lenses more than cover it so it's not an
>> issue I guess. A full frame however might be different.
>> If a lens open at f1.4 vignetting with 35mm film, then for sure it
>> will with a full-frame sensor.
>> -Rich
>
>Yes, but, Rich, your original implication was that 35mm film lenses would
>vignette on digital cameras (FF) BECAUSE they were used on digital cameras.
>To wit: "Vignetting is one of the failings you see when 35mm FILM lenses are
>used on digital cameras." Since the 50mm 1.4 doesn't vignette on film, I
>certainly wouldn't expect it to vignette on digital, and the image you
>posted doesn't show any vignetting, only light variations on the background.

Assuming that is what the near-symmetric variations are.
-Rich
Anonymous
September 13, 2005 9:51:26 AM

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

"Rich" <none@none.com> wrote in message
news:gg7ci15c01sgqffjuajm7trpiuks6rm3qb@4ax.com...
> On Mon, 12 Sep 2005 02:46:34 -0700, "Skip M" <shadowcatcher@cox.net>
> wrote:
>
>>
>>Yes, but, Rich, your original implication was that 35mm film lenses would
>>vignette on digital cameras (FF) BECAUSE they were used on digital
>>cameras.
>>To wit: "Vignetting is one of the failings you see when 35mm FILM lenses
>>are
>>used on digital cameras." Since the 50mm 1.4 doesn't vignette on film, I
>>certainly wouldn't expect it to vignette on digital, and the image you
>>posted doesn't show any vignetting, only light variations on the
>>background.
>
> Assuming that is what the near-symmetric variations are.
> -Rich

The "near symmetric" may be your clue. Vignetting is usually symmetrical,
not "near." Given a symmetrical crop. But the intensity of the shadow was
my other clue, the edges of a vignette would be the same, these aren't.
And that has nothing to do with you implying that the problem is worse with
full frame digital than it is with film.

--
Skip Middleton
http://www.shadowcatcherimagery.com
September 14, 2005 12:59:01 AM

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

On Tue, 13 Sep 2005 05:51:26 -0700, "Skip M" <shadowcatcher@cox.net>
wrote:

>"Rich" <none@none.com> wrote in message
>news:gg7ci15c01sgqffjuajm7trpiuks6rm3qb@4ax.com...
>> On Mon, 12 Sep 2005 02:46:34 -0700, "Skip M" <shadowcatcher@cox.net>
>> wrote:
>>
>>>
>>>Yes, but, Rich, your original implication was that 35mm film lenses would
>>>vignette on digital cameras (FF) BECAUSE they were used on digital
>>>cameras.
>>>To wit: "Vignetting is one of the failings you see when 35mm FILM lenses
>>>are
>>>used on digital cameras." Since the 50mm 1.4 doesn't vignette on film, I
>>>certainly wouldn't expect it to vignette on digital, and the image you
>>>posted doesn't show any vignetting, only light variations on the
>>>background.
>>
>> Assuming that is what the near-symmetric variations are.
>> -Rich
>
>The "near symmetric" may be your clue. Vignetting is usually symmetrical,
>not "near." Given a symmetrical crop. But the intensity of the shadow was
>my other clue, the edges of a vignette would be the same, these aren't.
>And that has nothing to do with you implying that the problem is worse with
>full frame digital than it is with film.

Take a look at any picture with illumination variations due to the
scene. Then try to determine if vignetting is symmetrical.
-Rich
Anonymous
September 14, 2005 6:50:58 PM

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

"Rich" <none@none.com> wrote in message
news:ldtei1ds8aahigpblc9no163as67s6hak8@4ax.com...
SNIP
> Take a look at any picture with illumination variations due
> to the scene. Then try to determine if vignetting is symmetrical.

That would be a flawed test procedure.

Bart
Anonymous
September 14, 2005 8:18:51 PM

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

In article <PfIVe.30$2o.22@fed1read05>, Skip M <shadowcatcher@cox.net>
writes
>"Rich" <none@none.com> wrote in message
>news:gg7ci15c01sgqffjuajm7trpiuks6rm3qb@4ax.com...
>> On Mon, 12 Sep 2005 02:46:34 -0700, "Skip M" <shadowcatcher@cox.net>
>> wrote:
>>
>>>
>>>Yes, but, Rich, your original implication was that 35mm film lenses would
>>>vignette on digital cameras (FF) BECAUSE they were used on digital
>>>cameras.
>>>To wit: "Vignetting is one of the failings you see when 35mm FILM lenses
>>>are
>>>used on digital cameras." Since the 50mm 1.4 doesn't vignette on film, I
>>>certainly wouldn't expect it to vignette on digital, and the image you
>>>posted doesn't show any vignetting, only light variations on the
>>>background.
>>
>> Assuming that is what the near-symmetric variations are.
>> -Rich
>
>The "near symmetric" may be your clue. Vignetting is usually symmetrical,
>not "near." Given a symmetrical crop. But the intensity of the shadow was
>my other clue, the edges of a vignette would be the same, these aren't.
>And that has nothing to do with you implying that the problem is worse with
>full frame digital than it is with film.
>
Looking at the original picture, I don't think the darkening is
vignetting; the bottom left corner (the only one not lit by background
lights) does not seem to show any fall-off, whereas the others do, in
varying amounts.

However, it is pretty pointless to spend time arguing about whether or
not a lens vignettes by looking at a picture with uneven lighting like
this. The only way (short of an optical bench and a photometer) to be
sure is to take a picture of an evenly-lit plain light coloured wall
exactly square on to the camera. The, if you can see darkening in the
corners, it is vignetting.

But I think most of us don't expect the OP to pay any attention to
logic.

David
--
David Littlewood
!