Closing down aperture reduces resolution of lens?
Godfrey DiGiorgi
down about 2-3 stops from wide open. As you reach the end aperture
range where the physical aperture is the smallest, the effects of
diffraction will step in and begin to degrade performance again.
In my experience, this generally happens only at the very smallest
aperture settings available, if at all, because the manufacturers
generally limit the minimum aperture size to eliminate it.
Godfrey
In article <3E066BD6...@prontoREMOVETHISmail.com>, AC/DCdude17
<Je...@prontoREMOVETHISmail.com> wrote:
> I seem to recall reading a page about resolution of photographic lens
> and film that mentions reduced lens resolution when aperture is narrowed
> down. Verification??
Robert Monaghan
yes, diffraction is approx. 1600/f# as a rule of thumb (maybe 1000/f#
for 50% contrast); anyway, at f/2 you have max. 800 lpm , at f/4, you
get 400 lpmm, f/8 is 200 lpmm, f/16 is 100 lpmm, and so on for a
diffraction limited lens (best possible performance..).
However, most real world affordable lenses are not diffraction limited,
but have significant aberrations wide open, so stopping down improves
them. This is why f/4 or f/5.6 is often a peak resolution - f/8 for even
modest lenses and slow ones usually found in 35mm photogr.
Note that this is "aerial" lens resolution; the on film values are
usually limited by the film resolution, often 100 lpmm max. for film.
hth bobm
--
* Robert Monaghan POB752182 So. Methodist Univ., Dallas Tx 75275 *
* Third Party 35mm Lenses: http://medfmt.8k.com/third/index.html *
* Medium Format Cameras: http://medfmt.8k.com/mf/index.html *
Tony Spadaro
enough to worry about. Most lenses will not close down to the point where
the image is noticably damaged by diffraction.
--
http://chapelhillnoir.com
and partial home of
The Camera-ist's Manifesto
The Links are at
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"AC/DCdude17" <Je...@prontoREMOVETHISmail.com> wrote in message
news:3E066BD6...@prontoREMOVETHISmail.com...
> X-No-Archive: Yes
David J. Littleboy
"Tony Spadaro" <tspa...@ncmaps.rr.com> wrote in message
news:_zzN9.57352$Rt1.2...@twister.southeast.rr.com...
> Diffraction causes small apertures to lose sharpness, but in general not
> enough to worry about. Most lenses will not close down to the point where
> the image is noticably damaged by diffraction.
If you are scanning Provia 100F, Velvia, Tech Pan at 4000 dpi, you should be
able to notice the difference between f/8 and f/16 or f/22...
David J. Littleboy
Tokyo, Japan
Don Stauffer
high an f/# their lenses stop down to is a cost item, not avoiding
diffraction.
Another factor here. The blur shape due to diffraction is different
than for most geometric aberrations. Many people accept loss of
resolution of very high f/# because it is more of a softening than a blur.
That is, it adds a subtle, slight fog to whole scene, somewhat like
flare, rather than blurring edges severely.
In terms of spot profile, a defocus, or many aberrations, are a distinct
bump. But profile of diffraction is a sharper central peak with low
foothills that extend a long way from center of peak.
There were soft focus filters available that were essentially screens,
with a diffraction pattern from each hole in the screen. These were
popular for portrait work.
Pinhole cameras/lenses give this same effect.
--
Don Stauffer in Minnesota
stau...@usfamily.net
webpage- http://www.usfamily.net/web/stauffer
David Littlewood
<rmon...@smu.edu> writes
>
>yes, diffraction is approx. 1600/f# as a rule of thumb (maybe 1000/f#
>for 50% contrast); anyway, at f/2 you have max. 800 lpm , at f/4, you
>get 400 lpmm, f/8 is 200 lpmm, f/16 is 100 lpmm, and so on for a
>diffraction limited lens (best possible performance..).
>
> However, most real world affordable lenses are not diffraction limited,
>but have significant aberrations wide open, so stopping down improves
>them. This is why f/4 or f/5.6 is often a peak resolution - f/8 for even
>modest lenses and slow ones usually found in 35mm photogr.
Notice that the better corrected the lens, the larger aperture will be
its best performing one. Most good enlarging lenses are at their best at
no more than one stop from maximum aperture, though that is partly
because the enlarging effect magnifies the blur. (Expressed more
scientifically, it is the effective aperture of the lens at the
magnification used which governs resolution, and effective aperture =
marked aperture*(1+magnification).)
>
>Note that this is "aerial" lens resolution; the on film values are
>usually limited by the film resolution, often 100 lpmm max. for film.
>
Also be aware that film resolution and lens resolution interact in
vector fashion. That is to say:
Overall resolution = 1/(1/film resolution^2 + 1/lens resolution^2)^-2
To see what this means, for a film of resolving power 100 lp/mm, the
following lens res figures would give the composite res figures shown on
the right
Lens res 1000 lp/mm Composite resolution 99.50 lp/mm
Lens res 800 lp/mm Composite resolution 99.23 lp/mm
Lens res 600 lp/mm Composite resolution 98.64 lp/mm
Lens res 400 lp/mm Composite resolution 97.01 lp/mm
Lens res 200 lp/mm Composite resolution 89.44 lp/mm
Lens res 100 lp/mm Composite resolution 70.71 lp/mm
Lens res 50 lp/mm Composite resolution 44.72 lp/mm
Lens res 25 lp/mm Composite resolution 24.25 lp/mm
Thus, as a rough guide, if either resolution figure is more than 4 times
the other, it will have no significant effect on the composite
resolution. Even 2 times is fairly modest in its effect; it is only when
the two figures are quite close together that the poorer figure does not
totally dominate.
This explains, in a little more detail, why you do not see the effects
of diffraction in real-world results on film. At f/8, the maximum
resolution from a perfect lens is about 200 lp/mm. at f/11, it is about
145 lp/mm, composite figure about 80 lp/mm. Now I bet not many people
could tell the difference between 90 and 80 lp/mm by unaided
observation. In the real real world, with lower film resolution, the
differences would be minuscule. Only below f/16 (lens res < 100 lp/mm)
would the diffraction effects really show.
Note that, on the basis of the effective aperture formula noted above,
these figures will be worse for macro work. For a macro lens at 1:1
ratio, the marked f/8 therefore becomes an effective f/16. This applies
to the resolution calculation just as it does for exposure measurements.
Must go now as the delivery man has just delivered my EOS 1nRS during
the time I wrote this. I plan to spend time over Christmas trying to
capture some breaking balls (get a life!).
--
David Littlewood
Neuman - Ruether
Even in low-resolution systems, like video cameras,
the effects of diffraction can easily be seen. At
this URL are samples of stills shot with a video
camera (Sony VX2000), where stopping down below
about f4 gradually softens image-center detail.
The surprise for me, after putting up this web page
(using the still-photo function of the camera), was
finding out that the motion-video images (which are
even lower in resolution) also clearly showed the
effects of diffraction...
See: www.ferrario.com/ruether/diffraction.htm.
David Ruether
rp...@cornell.edu
http://www.ferrario.com/ruether
Hey, check out www.visitithaca.com too...!
Tony Spadaro
(or possibly 11) and f22 was barely noticable using a 2700 dpi scanner. I'm
planning to reshoot for the test and scanning at 4000 dpi before putting it
on the new website but need a warm windless day for the shooting. I used
Provia F100.
--
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and partial home of
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"David J. Littleboy" <dav...@gol.com> wrote in message
news:au6juk$2fp$1...@nnrp.gol.com...
Tony Spadaro
--
http://chapelhillnoir.com
and partial home of
The Camera-ist's Manifesto
The Links are at
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"Neuman - Ruether" <rp...@cornell.edu> wrote in message
news:3e0c378a...@newsstand.cit.cornell.edu...
Neuman - Ruether
<dav...@gol.com> wrote:
>"Tony Spadaro" <tspa...@ncmaps.rr.com> wrote in message
>news:_zzN9.57352$Rt1.2...@twister.southeast.rr.com...
>> Diffraction causes small apertures to lose sharpness, but in general not
>> enough to worry about. Most lenses will not close down to the point where
>> the image is noticably damaged by diffraction.
>If you are scanning Provia 100F, Velvia, Tech Pan at 4000 dpi, you should be
>able to notice the difference between f/8 and f/16 or f/22...
>David J. Littleboy
>Tokyo, Japan
Even in low-resolution systems, like video cameras,
the effects of diffraction can easily be seen. At
this URL are samples of stills shot with a video
camera (Sony VX2000), where stopping down below
about f4 gradually softens image-center detail.
The surprise for me, after putting up this web page
(using the still-photo function of the camera), was
finding out that the motion-video images (which are
even lower in resolution) also clearly showed the
effects of diffraction...
See: www.ferrario.com/ruether/diffraction.htm.
David Ruether
On Mon, 23 Dec 2002 17:48:17 GMT, "Tony Spadaro"
<tspa...@ncmaps.rr.com> wrote:
> I would assume that the video lenses are more to blame.
?????????
Unlikely if you see a decline in resolution with
stopping down - that is generally a diffraction
effect (and in the samples, you can see the
diffraction effect increasing with smaller stops
in the increasing sizes of the "star" sun
reflections on the car [the star is a combination
of diffraction around straight sides of the
diaphragm leaves, and of a "HAD" CCD effect [the
vertical rays are caused by this...]).
Neuman - Ruether
<tspa...@ncmaps.rr.com> wrote:
>I use to have a test of this up on my old website. The difference between f8
>(or possibly 11) and f22 was barely noticable using a 2700 dpi scanner. I'm
>planning to reshoot for the test and scanning at 4000 dpi before putting it
>on the new website but need a warm windless day for the shooting. I used
>Provia F100.
With B&W film-tests, using a good 10X magnifier, it is
easy to see the decline in resolution stop-by-stop from
f8 to smaller stops, with f16 generally being the last
"good" stop for optimum results at the image center with
35mm... (not that you cannot "stretch" to f22, but the
results are noticeably less sharp than at f8...). The
differences may be less obvious with a reduction in
resolution with copying, as with scanning...
Tony Spadaro
look at them at arms length. If you want to be the very model of an ultra
tech dweeb do your tests with a 50 power microscope - your results will be
just about as meaningful and you'll sound ever so much more scientific.
--
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and partial home of
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"Neuman - Ruether" <rp...@cornell.edu> wrote in message
news:3e0b88bb...@newsstand.cit.cornell.edu...
David Littlewood
Spadaro <tspa...@ncmaps.rr.com> writes
> But people dont stare at their prints with a 10x magnifier. They tend to
>look at them at arms length. If you want to be the very model of an ultra
>tech dweeb do your tests with a 50 power microscope - your results will be
>just about as meaningful and you'll sound ever so much more scientific.
>
with a 10x magnifier - which is quite a good proxy for a print but
without as much degradation from the enlarging process (besides, who
wants to *print* test shots - now that would make one a dweeb).
--
David Littlewood
John Stafford
> Also be aware that film resolution and lens resolution interact in
> vector fashion. That is to say:
>
> Overall resolution = 1/(1/film resolution^2 + 1/lens resolution^2)^-2
Interesting stuff, David. I especially appreciate the suggestion that
there are real-world limits of the metrics.
See: http://bobatkins.photo.net/info/resolution.html
Near the end of the page is the assertion that while stopping down
might reduce the ultimate resolution of a lens, it improves it in the
region of 100-150 lp/mm, a point of relevance because that's the
limit: the lp/mm resolving power of film.
But I stand aside on this. I go with what I can actually see. I have
found that it is easy to mistake mere confusion of detail for
diffusion: when an image has greater DOF, the object in focus may not
be as conspicuous as it is with a wider aperture so they presume
diffraction is the issue, when in fact it is the mistake of the human
eye. (By conspicuous I mean the object in focus at a wider aperture is
distinctly separated from the background and usually brighter, and
_apparently_ sharper.) And then there are illusions caused by certain
color contrasts. The human eye is not a camera.
Tony Spadaro
looking for trouble you generally find it. Diffraction is negligible when
viewed normally. This is more like those characters who think four inches is
the "normal" viewing distance for 16x20 prints.
--
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and partial home of
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"David Littlewood" <da...@nospam.demon.co.uk> wrote in message
news:jV$etZA1d...@dlittlewood.demon.co.uk...
Neuman - Ruether
<tspa...@ncmaps.rr.com> wrote:
> Even a mere 10x on the slide is being more than anal retentive. If you go
>looking for trouble you generally find it. Diffraction is negligible when
>viewed normally. This is more like those characters who think four inches is
>the "normal" viewing distance for 16x20 prints.
If your standards are low enough, almost any other
standard becomes irrelevant...;-)
Tony Spadaro
assinine "test" why the hell are you wasting time on 35mm when obviously
only 8x10 or larger will give you the results you feel you need? Or are you
only anal retentive north by north west and quite incapable of knowing what
words you are parroting today?
I suspect the latter.
--
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and partial home of
The Camera-ist's Manifesto
The Links are at
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"Neuman - Ruether" <rp...@cornell.edu> wrote in message
news:3e0c9829...@newsstand.cit.cornell.edu...
David J. Littleboy
"Tony Spadaro" <tspa...@ncmaps.rr.com> wrote:
> And if you zre anal retentive enough to believe the validity of your own
> assinine "test" why the hell are you wasting time on 35mm when obviously
> only 8x10 or larger will give you the results you feel you need?
Despite the rudeness, there is a hint of a real issue lurking here; namely
you are effectively claiming that the loss of quality due to diffraction is
of the same order of magnitude as the other issues (grain, film resolution,
degradation in scanning/printing) that limit the quality of larger prints. I
don't have links to equivalent tests for 35mm lenses, but if you look at the
lp/mm values in:
http://www.hevanet.com/cperez/MF_testing.html
You'll notice that a lot of these lenses are pretty funky at f/22, but that
f/16 varies with the lens. (Here "pretty funky" means "20 to 30% lower
resolution than f/5.6 or f/8".) A lot of lenses hold up quite nicely at
f/16.
Is this enough to make a difference in a 9x or 10x (8x10, maybe with a touch
of cropping) prints? I suspect that these numbers aren't enough to tell,
since they are (presumably) 10% MTF for high contrast targets, and you
really need 50% MTF for low contrast targets* to be meaningful on a print of
real-world subject matter...
*: And I suspect such numbers for most lenses would be incredibly
depressing.
Tony Spadaro
is the most over-rated bugaboo in all of the obsessive compulsive world of
the self styled scientific photographer.
--
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and partial home of
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"David J. Littleboy" <dav...@gol.com> wrote in message
news:auavo1$3om$1...@nnrp.gol.com...
Don Stauffer
diffraction for all hand-held shots. I remember a test done somewhere
on handheld versus tripod even for 60th and 125th exposures. There WAS
considerable blur. The tests as I remember used a pretty good film and
was in either a photo mag or book.
--
Neuman - Ruether
<stau...@usfamily.net> wrote:
>I suspect that motion blur accounts for more degradation than
>diffraction for all hand-held shots. I remember a test done somewhere
>on handheld versus tripod even for 60th and 125th exposures. There WAS
>considerable blur. The tests as I remember used a pretty good film and
>was in either a photo mag or book.
Yes. Even tripod-mounting does not guarantee optimum
results, though... When shooting handheld for best
sharpness, I would take about five frames of the
same thing, and select for sharpness - and even under
difficult conditions, there would usually be one good
frame (and even under ideal conditions, there would
usually be one bad frame...). Some of us *do* care
about image sharpness, and take measures to optimize
it, like avoiding too-small/wide stops, camera-shake,
poor lens samples/types, etc....;-) And, it is possible
to learn how to hold a camera steady during an exposure.
The first step is buying a good 10X magnifyer, and
figuring out which frames are really sharp, and which
ones aren't - and why. Eventually, the percentage
of sharp frames goes up...
Neuman - Ruether
news:3e0c9829...@newsstand.cit.cornell.edu...
> If your standards are low enough, almost any other
> standard becomes irrelevant...;-)
> David Ruether
On Tue, 24 Dec 2002 23:13:55 GMT, "Tony Spadaro"
<tspa...@ncmaps.rr.com> wrote:
> And if you zre anal retentive enough to believe the validity of your own
>assinine "test" why the hell are you wasting time on 35mm when obviously
>only 8x10 or larger will give you the results you feel you need? Or are you
>only anal retentive north by north west and quite incapable of knowing what
>words you are parroting today?
> I suspect the latter.
There are many reasons for choosing one format over
another, and I choose one that permits reliably-sharp
results hand-held (among other reasons, like the
relative ease of storage/display of images, the wide
range of good, affordable optics available, etc.).
Choosing 35mm does not imply that I should drop all
standards for sharpness, tonality, etc. Quite the
opposite - getting good results from 35mm requires
more attention to "details" than it does for larger
formats... I'm mystified why you would object to some
effort to optimize results in this format, and dismiss
attempts to do so (and do it rudely...;-). Do you
feel that you have no control over 35mm image quality,
and resent others who may know some of the "ins and
outs" of successfully using 35mm...? ;-)
Tony Spadaro
perhaps wrongly, that any sane person looks at his pictures in a fairly
normal manner instead of studying each and eery one with a 10x loupe looking
for the smallest imperfection. Dust on the subject is a bigger problem than
diffraction on a 50mm macro lens at 1:1 with an aperture of f32.
Diffraction is simply not an important factor at any aperture the lenses
are designed to use.
--
http://chapelhillnoir.com
and partial home of
The Camera-ist's Manifesto
The Links are at
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Robert Monaghan
Dust on the subject is a bigger problem than
diffraction on a 50mm macro lens at 1:1 with an aperture of f32.
there isn't that much dust around here even in a good ole' Texas dust storm
clearly diffraction _is_ a problem at f/stops beyond f/22 for many of us;
for most lens makers, it is enough of a problem they don't even make such
an f/stop available for 35mm macro lenses besides a few macro lenses (and
telephotos). For 50% contrast (1000/f#), that's down to 30 lpmm, and not
esp. stellar (using Roger Hick's rule of thumb on diffraction).
I do have a "pan focus" 50mm f/40 (that's f/forty) lens which also clearly
shows the problem with diffraction when used with a 50mm lens on 35mm SLR.
I do agree that film resolution is far more limiting, esp. with color
films.
However, my earlier point is that if you _are_ using a high quality lens
and a high resolution black and white film, some of which hit 300+ lpmm,
then you _do_ have to worry about diffraction at f/8 (1000/8~= 125 lpmm at
50% contrast limits), so you should use a wider f/stop such as f/4 (250
lpmm"); otherwise diffraction _will_ limit your max. resolution at f/8 etc.
The general amateur photogr. view is that to get a sharper image you
should stop down towards f/16. This is _not_ true in most situations in
35mm - you get a max. sharpness (with the right films) a few stops from
wide open (unless you have a lens that is diffraction limited wide open ;-)
in the typical case. You do get more DOF, but that's a different thing ;-)
grins bobm
Neuman - Ruether
<tspa...@ncmaps.rr.com> wrote:
> Because I'm obviously a much ruder person than you - and one who assumes,
>perhaps wrongly, that any sane person looks at his pictures in a fairly
>normal manner instead of studying each and eery one with a 10x loupe looking
>for the smallest imperfection. Dust on the subject is a bigger problem than
>diffraction on a 50mm macro lens at 1:1 with an aperture of f32.
> Diffraction is simply not an important factor at any aperture the lenses
>are designed to use.
I look at film, not prints at 10X (10X on a print
reveals nothing of interest...). If you think f32
on a Micro-Nikkor is sharp, I've got a bridge in
Brooklyn for sale, at a VERY good price....;-)
Or, run an aperture sequence from f8 to f32, look
at the results on film with a good 10X (hardly a
taxing magnification), and you will see a BIG
difference in the image going from f8 to f32 (or
even from f16 to f32). If you don't care that
the image is noticeably sharper at f16 or wider,
that's OK for you, but not for some of us who are
looking for the best sharpness (as one of many
image aspects to be optimized...). I'm assuming
that you mean the "marked" f32 on the lens (which
will give you an effective stop of f64 at 1:1 with
normal extension). If you mean the lens-marked f16
(which becomes effectively f32 at 1:1), I would
agree that this is an acceptable stop to use for
macro work with some gear... BTW, a big air
hand-syringe works wonders for cleaning macro
subject areas... Also BTW, I have some macro
images you may find interesting, at:
http://www.ferrario.com/ruether/phun.html
("Bugs"), all "hand-held", at magnifications
up to 3X, including some insects caught in the
air...
Tony Spadaro
apertures the lens is designed to use. Dust on the subject matter in a 1:1
macro shot pretty much ruins the shot - and it's amazing how much of it
there can be on an item you think you've cleaned carefully.
You may get maximum sharpness at f8 but you don't get maximum dof -
which has a lot more to do with percieved sharpness than the diffraction at
f16 or even f22. Obviously for longer lenses diffraction is going to be
less (as is dof) for any given aperture as the actual size of the aperture
is larger. A
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"Robert Monaghan" <rmon...@smu.edu> wrote in message
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Tony Spadaro
idea of a big difference is strictly horse liniment. I've done diffraction
tests using very fine grain films and good quality lenses. The tests have
taught me to ignore diffraction paranoids as much as I ignore the multitute
of other people who obsess on buggaboos.
I keep a filter on my lenses at all times --- whooo degradation city,
man!
I use films faster than ISO 10 ---- Aach! Disgusting grain!
I stop down to f11, and 16 ----- Gasp! Run, the diffractors are coming!
And I take pictures with content - instead of pictures designed to show
my ability to follow the rules of the anal types.
I used to read Photo Techniques back when they still had occasional
articles relevant to photography. I remember all the pictures they printed.
Perfectly exposed -- zoned to a degree Adams would have found excessive.
Perfectly Composed -- Smack on the rule of thirds -or as we Irish call it,
Da Rule of Turds.
Perfectly printed -- complete with unsharp masking, and with a full tonal
range from jet black to paper white in every shot. Of course it's on the
finest of papers and archivally processed in fresh chemicals with a
guarantee to outlast the photographer by a couple thousand years.
And
Perfectly Boring -- in that search for the best sharpness, and the best
print quality and the best of everything, they've forgotten that there is
supposed to be something of interest in the picture.
Even Adams wasn't worried about diffraction. Ask Cartier-Bresson if he
even considers diffraction - hell, some of his most famous shots aren't even
in focus. Or perhaps George Lepp who uses two TCs a 12mm spacer and a number
1 close up ring to do macro shots of insects in the field. According to the
article stopping down all the way gives him sufficient DOF for the shots to
work -- dof not diffraction is the problem he feels must be overcome.
Ask just about any successful artist or professional how much time they
spend worrying about diffraction. Start with the guys who sell prints made
from Holga negatives. Or better yet the ones who use pinhole cameras -- at
f180 a 50mm pinhole camera shows more diffraction than you can imagine. What
is it those people have that the careful, scientific perfectionist
photographer with his diffraction rules and his dof charts and his unsharp
masks lack --- Usually - an interesting picture.
Come up with an interesting picture, and let the diffraction fall where
it may. If you can't come up with an interesting picture the diffraction or
lack thereof is still of no importance as nobody's looking.
--
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and partial home of
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The Links are at
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"Neuman - Ruether" <rp...@cornell.edu> wrote in message
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Neuman - Ruether
<tspa...@ncmaps.rr.com> wrote:
Well, you raised many interesting issues, but have missed
the point of the thread completely...;-) And, you obviously
have never looked at the images on my web page...;-) Yes,
all technique (and even the apparent lack thereof...) needs
to serve the image (which, in the end, is all we have before
us), and yes, there are no *absolute* standards for what the
needs of the image are, let alone what constitutes "good
technique", BUT: *assuming no aesthetic needs in the image
for degrading these characteristics*, one can say that
optimum sharpness of the appropriate parts of the image,
the presence of a good black, the absence of dirt, stains,
and other irrelevant intrusions on the image "quality",
ETC., ETC., ***ARE*** desirable aspects of the image, and
if the desirable image aspects can be optimized, why not
do this?! Or, why would I take a Leica M6 and an aspheric
35mm f2 and shoot it hand-held at a slow speed (while
shaking...) at the smallest stop for all my work, unless
my "thing" is blurry photographs? (And, if so, why not
use "less able" gear...?;-) And, why would I shoot a
landscape at a stop I know to be somewhat unsharp compared
with nearby stops for the dubious gain of a tad more DOF?!
(ETC.)
Now for the specifics...
> I would never accuse a micro Nikkor of being sharp at any aperture.
You have just lost any credibility you had...;-)
>Your
>idea of a big difference is strictly horse liniment. I've done diffraction
>tests using very fine grain films and good quality lenses. The tests have
>taught me to ignore diffraction paranoids as much as I ignore the multitute
>of other people who obsess on buggaboos.
The effects are subtle (unless carried to an extreme) - but
subtle effects can add up for a superior resulting image...
> I keep a filter on my lenses at all times --- whooo degradation city,
>man!
So do I (surprise! ;-) - I've done the tests, and this one
does not degrade the image quality *under most
conditions*...
> I use films faster than ISO 10 ---- Aach! Disgusting grain!
Not necessarily - but one must become more selective with
film choices as the speed rises to maintain desired
qualities (which may include intentional "graininess"...).
> I stop down to f11, and 16 ----- Gasp! Run, the diffractors are coming!
Both are fine - it is f22 that is "iffy" in 35mm, and f32
that is generally not acceptable...
> And I take pictures with content - instead of pictures designed to show
>my ability to follow the rules of the anal types.
As would any "serious" photographer, while using knowledge
of technical aspects to optimize the outcome. Ignoring the
second is like handing a paint brush to a 5-year old - good
results are likely to be the result only of accident, even
if the kid really is "talented" visually...
> I used to read Photo Techniques back when they still had occasional
>articles relevant to photography. I remember all the pictures they printed.
>Perfectly exposed -- zoned to a degree Adams would have found excessive.
>Perfectly Composed -- Smack on the rule of thirds -or as we Irish call it,
> Da Rule of Turds.
>Perfectly printed -- complete with unsharp masking, and with a full tonal
>range from jet black to paper white in every shot. Of course it's on the
>finest of papers and archivally processed in fresh chemicals with a
>guarantee to outlast the photographer by a couple thousand years.
>And
>Perfectly Boring -- in that search for the best sharpness, and the best
>print quality and the best of everything, they've forgotten that there is
>supposed to be something of interest in the picture.
Of course - good technique without good "vision" is useless;
but good vision without good technique is "hobbled" and
very limited...
> Even Adams wasn't worried about diffraction.
With contact prints from 8x10, diffraction is a
non-issue...;-) With 4x5 with great enlargements, it
is - but only around f32-64 or so... Adams didn't
need to worry much about diffraction with the formats
he used - but you can bet he did the tests, though...;-)
>Ask Cartier-Bresson if he
>even considers diffraction - hell, some of his most famous shots aren't even
>in focus.
Yes - I've seen his prints, and they are close to worthless
in their original form (the poor technique kills the
vision); it is only with the careful making for the books
of the small reproduction images that his work really
lives - the small images corrected many of the problems of
focus, sharpness, poor tonality, etc. that existed in the
originals and interfered with the overall image "meaning"...
It is the maker of the CB reproductions that "fixed" many
of CB's technical errors, and as a result, strengthened his
vision as we know it. This is an excellent example of the
need for good *appropriate* technique to carry the meaning
of the images, without which they have little value...
>Or perhaps George Lepp who uses two TCs a 12mm spacer and a number
>1 close up ring to do macro shots of insects in the field.
On many of my macro images I use a non-macro 200mm
tele-design lens (not usually considered a good choice for
close focus...) + achromat + tube + teleconverter - and get
very sharp images *at the optimum stops* for the
combinations. There are no "rules" for what gear will and
will not work well - which is the point of "anal"
testing: to find what works best and what doesn't...
>According to the
>article stopping down all the way gives him sufficient DOF for the shots to
>work -- dof not diffraction is the problem he feels must be overcome.
It is a serious problem for high-magnification work, and
sometimes a compromise is made - but without knowing what
that involves, one cannot make an informed choice. I would
not simply "stop down all the way", though - the results
are likely to be softer than one might like, and with only
a stop and a half wider, could be considerably sharper and
possibly without serious loss of DOF...
> Ask just about any successful artist or professional how much time they
>spend worrying about diffraction. Start with the guys who sell prints made
>from Holga negatives. Or better yet the ones who use pinhole cameras -- at
>f180 a 50mm pinhole camera shows more diffraction than you can imagine. What
>is it those people have that the careful, scientific perfectionist
>photographer with his diffraction rules and his dof charts and his unsharp
>masks lack --- Usually - an interesting picture.
Of course - *any* techniques, including intentionally "bad"
ones, can be used to make good photos (as can "bad" gear"),
but the point is, with knowledge, skill, vision, and good
gear, one can shoot a FAR wider *range* of "good" images,
more easily... Do you really want to be limited to the
capabilities of a Holga? Or to the capabilities of f32?
> Come up with an interesting picture, and let the diffraction fall where
>it may. If you can't come up with an interesting picture the diffraction or
>lack thereof is still of no importance as nobody's looking.
Well, of course! The final image is ***ALWAYS*** what
counts! But, there are "bits" along the way to making
it that can contribute to its being better...;-)
Tony Spadaro
site is one of those I plan to link from the page I'm adding to mine titled
"Photographers of the Usenets"
But this has little or nothing to do with diffraction. Your statement on
Cartier-Bresson is the most telling thing you say.
>>>>>> "Yes - I've seen his prints, and they are close to worthless
> in their original form (the poor technique kills the
> vision); it is only with the careful making for the books
> of the small reproduction images that his work really
> lives - the small images corrected many of the problems of
> focus, sharpness, poor tonality, etc. that existed in the
> originals and interfered with the overall image "meaning"...
> It is the maker of the CB reproductions that "fixed" many
> of CB's technical errors, and as a result, strengthened his
> vision as we know it. This is an excellent example of the
> need for good *appropriate* technique to carry the meaning
> of the images, without which they have little value."
<<<<<<
Think about it. How long has Cartier-Bresson been a recognized and highly
admired artist? Longer than you or I have lived --- quite a bit longer.
There is more to photography than craftsmanship, and there is less to
craftsmanship than art. The reason why the impressionist painters were
called impressionists is because one "art critic" said at the first show -
"That's not a picture of an XXXXX it's just an impression of it" He was
being derogatory -- the impressionists embraced the label. There is a much
bigger world out there than the razor sharp full toned, un-diffracted,
absolutely frozen and while there is no reason on earth for you or anyone
else to practice any other form of photography, you should at very least
recognise that there is actually more in heaven and on earth than dreamt
about in your philosophy.
There are very few people out there who worry about diffraction ruining
a shot at f22, and there is a pretty good reason for that, it's invisible
to the naked eye. I scan my pictures at 4000 dpi and usually do the spotting
at 100% in photoshop -- I've got a pretty good idea of what my pictures look
like on a level that few photographers ever see -- believe me a good size
screen is a lot easier on the eyes than dealing with a light table and a
loupe. Diffraction is the least of the effects on my pictures.
However, if you feel a 10x loupe is the standard by which you will judge
your pictures, fine. If you feel a 10x loupe is the standard by which you'll
judge my pictures, also fine. If you feel a 10x loupe is the standard by
which the world should judge pictures, foggedaboudit.
--
http://chapelhillnoir.com
and partial home of
The Camera-ist's Manifesto
The Links are at
http://home.nc.rr.com/tspadaro/links.html
"Neuman - Ruether" <rp...@cornell.edu> wrote in message
Neuman - Ruether
<tspa...@ncmaps.rr.com> wrote:
> But I have looked at your website, and I like your pictures. In fact your
>site is one of those I plan to link from the page I'm adding to mine titled
>"Photographers of the Usenets"
> But this has little or nothing to do with diffraction.
[....]
Unfortunately, my replies evaporated with a computer crash,
and I don't have the energy to reconstruct them. The
answers, basically, are in my post just above, anyway
(but with less detail) - which you did not read carefully,
or you would not have said what you did in the rest of your
response... Since this exchange appears to be going nowhere
now, I will end it (believe what you want, but if you read
my posts carefully, I think you would find that we are not
disagreeing on a lot...).
Tony Spadaro
--
http://chapelhillnoir.com
and partial home of
The Camera-ist's Manifesto
The Links are at
http://home.nc.rr.com/tspadaro/links.html
"Neuman - Ruether" <rp...@cornell.edu> wrote in message
news:3e0d7ae...@newsstand.cit.cornell.edu...