Sharpest Aperture?!
May 31, 2016 17:29:20 #
The more you read - the more the circle of confusion you sit in!
If you are the kind of person that records your 'shooting' as you do it you will end up with more notes than images.
If you are the person that reads Exif data from every great shot that you see, you will still end up disappointed, cause each shot is different and you will never have the right lens at the right time.
If you are a lazy person you will come up with a couple of settings for each lens that you own that kind of works most of the time.
if all else fails post process.
If you are the kind of person that records your 'shooting' as you do it you will end up with more notes than images.
If you are the person that reads Exif data from every great shot that you see, you will still end up disappointed, cause each shot is different and you will never have the right lens at the right time.
If you are a lazy person you will come up with a couple of settings for each lens that you own that kind of works most of the time.
if all else fails post process.
May 31, 2016 17:44:28 #
with my new D500 I found /11 to be the sharpest on 2 lenses the 17 to 35mm and the 18 to 300mm-- got to play around with the lens and camera to see what you get
May 31, 2016 18:07:32 #
RRS
Loc: Not sure
I do recall what the high acuteness developers and what they could do, I even recall those smells of the darkroom too. The one thing we all seem to forget is how close we seem to look at files (pictures) today (100%+) as to the viewing distance that we enjoyed those old B&W images.
May 31, 2016 18:09:02 #
May 31, 2016 22:45:38 #
dandi
Loc: near Seattle, WA
Mark7829 wrote:
In fact so many award winning images are not sharp at all. Art trumps technology every time.
Jun 2, 2016 15:37:08 #
amfoto1
Loc: San Jose, Calif. USA
The sharpest aperture varies, depending upon the lens...
IMO, Rockwell is over-analyzing things. For one, absolute sharpness isn't really all that critical all the time. Most of the hand-wringing about image sharpness is from pixel peepers who insist on viewing and evaluating their images at ridiculously high magnifications... way beyond the sizes they'll ever actually use them (at lower magnifications where the image might be just fine).
Much of what his article talks about is hyperfocal focusing technique.... and his argument is simply that he wants a smaller "circle of confusion" than DoF of lens scales is designed to render. No big deal, really!
Rockwell isn't really writing about what's the sharpest particular aperture with any given lens, but more about what gives you "sufficient" Depth of Field for any given image to be sharp over the entire range of distances you require.
If you want to know what's the sharpest lens of a particular lens, that's different and you can test yourself. Alternatively, you might be able to find lab tests that show it.
In most cases, it's a stop or two down from wide open. But, it depends. Some lenses are designed to be at or near their sharpest wide open.
I disagree that "fast lenses" tend to be soft wide open. In fact, many of my fastest lenses are also the ones that are optimized for wide open usage and at or very near their best there. 500/4, 300/2.8, 135/2, 70-200/4, 100-400 f4.5-5.6, 60/2.0 and 100/2.8 macro all are just as sharp wide open... or very nearly so. You'll have a hard time telling the difference in a print. (The strength of blur in the out of focus areas will actually tell you more about how large an aperture was used.)
OTOH, I know my 28/1.8, 50/1.4, 85/1.8, 24-70/2.8, 70-200/2.8, 28-135 f3.5-5.6, are noticeably sharper a stop down from wide open. With the zooms, it also matters what focal length is used... the difference is usually more notable in the telephoto focal lengths. And, it varies a lot how much difference it makes. In some it's very little... For example, it's usable wide open, but with my 50/1.4 I try to use it at f2 or f2.2 most of the time. With the 28-135 racked out all the way to 135mm, I try to always use f7.1 or smaller because I know it's a wee bit soft wide open at f5.6. At other focal lengths with that zoom, I don't worry much about it.
And, some previous points about diffraction are correct. Too small an aperture begins to cause loss of fine detail... lower resolution.
How small you can go depends upon the level of magnification that will be done with the final image. Most often, an 8x10 print is assumed when deciding how small an aperture is usable. From an APS-C camera, that's roughly 13X magnification, which from around 20MP camera diffraction starts to become a concern any smaller than f8. On the other hand, a full frame image is magnified approx. 8X to produce the same 8x10 print, so can tolerate a little smaller aperture, f11, before diffraction starts to have an effect.
So, I'd be a wary about using some of Ken Rockwell's recommended apertures... especially with an APS-C sensor camera!
Note: Diffraction was less a concern with film cameras.... though it still occurred. The reason we didn't worry about it was because we weren't looking at our film images massively magnified at "100%" on our monitors. Also, a lot of pros and advanced amateurs used larger formats.... 35mm was about the smallest, equal to today's "full frame" digital, which is now the largest format most shooters ever use. Medium format and large format cameras require far less magnification to make a print. That same 8x10 that's 8X from full frame or 35mm film... or 13X magnification from an APS-C or 16X from Four/Thirds... Heck it's only 2X from a 4x5" neg or slide... And it's only about 3.5X from a 6x7cm medium format film camera's negs and slides.
Yeah, sometimes we viewed our slides really large: projected on a screen... in really big prints... or even occasionally greatly enlarged for use on a billboard. But we viewed all those from quite a distance, many feet or tens-of-feet away! We weren't pixel peeping from 18 or 20", like we do today with our 100% image on our computer monitors today. On a typical monitor at native resolution, viewing an image from an 18 or 20MP APS-C camera at 100% is about like blowing it up to a five foot wide print - equal to around 60X or greater magnification - and then viewing it from 18 to 20" away!
Actually, Depth of Field (DoF) doesn't change with different formats alone. All other things being equal, it's exactly the same, regardless whether the camera is an APS-C digital or a 4x5 large format.
DoF changes depending upon aperture, focal length and distance.
However, what is true is that when we change format, in order to frame the subject the same way in practice we also have to either change focal length or distance to the subject... or a bit of both.
For example, approx. 30mm lens on an APS-C camera acts like a 50mm lens on "full frame" (24x36mm)... or a 75mm lens on 6x4.5cm... or 90mm on 6x7cm... or 180mm on 4x5". All those are roughly "standard" lenses on their respective formats. And the changes in focal length will cause a corresponding change in DoF, making it shallower as the focal length increases.
OTOH, if there were such a thing as a 30mm lens that could be utilized on all those formats, it would be a standard on the APS-C, act as moderately wide on full frame, or as a wide angle lens on 6x4.5 and 6.x7, and behave as an ultrawide on 4x5... and so long as you shot your subject from the same distance and with the same aperture, it would render exactly the same DoF on all of the formats. DoF would only change if you changed the lens aperture or moved closer to or farther from your subject with the camera and lens.
In practical application, the effect is actually just the opposite of what you suggest with your Ansel Adams reference.
The longer focal lengths used with larger formats make it "easier to blur down" a background. Or - alternatively - it's harder to achieve the same level of blurring with the smaller formats. Notice that for APS-C, "full frame" and 35mm film cameras there are quite a few lenses with f1.4, f1.8 and f2 apertures... even a few f1.2. In medium format systems, there are almost no lenses faster than f2.8, and even those are rather rare... More common medium format lenses are f3.5, f4 or slower. And, in 4x5 large format, it's almost unheard of for lenses to offer any larger than f5.6. Quite a few are only f8.
Yes, Ansel Adams tended to use pretty small apertures and longer exposures for his scenic shots. But he did that because he was looking for enough Depth of Field to render sharpness from foreground to infinity! He had a few 35mm and some medium format roll film cameras, but Adam's best known works were done with large format, sheet film 4x5, 5x7 and larger cameras. I shot quite a bit with 4x5 format in the past and with them often stopped down to f22, f32 and f45 for the same reasons. I also used medium format, but because I was more typically shooting portraits with those, would tend to use them closer to wide open.
BTW, Adam's also used the Zone System of metering, exposing and processing his images.... which today we might call "HDR". And his extensive notes show that when printing them, he did a whole lot of tweaking of his images... everything from his choice of paper and development chemistry to careful dodging and burning.... today we might call that "post-processing" or "Photoshopping". I suspect Ansel would have loved digital imaging!
IMO, Rockwell is over-analyzing things. For one, absolute sharpness isn't really all that critical all the time. Most of the hand-wringing about image sharpness is from pixel peepers who insist on viewing and evaluating their images at ridiculously high magnifications... way beyond the sizes they'll ever actually use them (at lower magnifications where the image might be just fine).
Much of what his article talks about is hyperfocal focusing technique.... and his argument is simply that he wants a smaller "circle of confusion" than DoF of lens scales is designed to render. No big deal, really!
Rockwell isn't really writing about what's the sharpest particular aperture with any given lens, but more about what gives you "sufficient" Depth of Field for any given image to be sharp over the entire range of distances you require.
If you want to know what's the sharpest lens of a particular lens, that's different and you can test yourself. Alternatively, you might be able to find lab tests that show it.
In most cases, it's a stop or two down from wide open. But, it depends. Some lenses are designed to be at or near their sharpest wide open.
I disagree that "fast lenses" tend to be soft wide open. In fact, many of my fastest lenses are also the ones that are optimized for wide open usage and at or very near their best there. 500/4, 300/2.8, 135/2, 70-200/4, 100-400 f4.5-5.6, 60/2.0 and 100/2.8 macro all are just as sharp wide open... or very nearly so. You'll have a hard time telling the difference in a print. (The strength of blur in the out of focus areas will actually tell you more about how large an aperture was used.)
OTOH, I know my 28/1.8, 50/1.4, 85/1.8, 24-70/2.8, 70-200/2.8, 28-135 f3.5-5.6, are noticeably sharper a stop down from wide open. With the zooms, it also matters what focal length is used... the difference is usually more notable in the telephoto focal lengths. And, it varies a lot how much difference it makes. In some it's very little... For example, it's usable wide open, but with my 50/1.4 I try to use it at f2 or f2.2 most of the time. With the 28-135 racked out all the way to 135mm, I try to always use f7.1 or smaller because I know it's a wee bit soft wide open at f5.6. At other focal lengths with that zoom, I don't worry much about it.
And, some previous points about diffraction are correct. Too small an aperture begins to cause loss of fine detail... lower resolution.
How small you can go depends upon the level of magnification that will be done with the final image. Most often, an 8x10 print is assumed when deciding how small an aperture is usable. From an APS-C camera, that's roughly 13X magnification, which from around 20MP camera diffraction starts to become a concern any smaller than f8. On the other hand, a full frame image is magnified approx. 8X to produce the same 8x10 print, so can tolerate a little smaller aperture, f11, before diffraction starts to have an effect.
So, I'd be a wary about using some of Ken Rockwell's recommended apertures... especially with an APS-C sensor camera!
Note: Diffraction was less a concern with film cameras.... though it still occurred. The reason we didn't worry about it was because we weren't looking at our film images massively magnified at "100%" on our monitors. Also, a lot of pros and advanced amateurs used larger formats.... 35mm was about the smallest, equal to today's "full frame" digital, which is now the largest format most shooters ever use. Medium format and large format cameras require far less magnification to make a print. That same 8x10 that's 8X from full frame or 35mm film... or 13X magnification from an APS-C or 16X from Four/Thirds... Heck it's only 2X from a 4x5" neg or slide... And it's only about 3.5X from a 6x7cm medium format film camera's negs and slides.
Yeah, sometimes we viewed our slides really large: projected on a screen... in really big prints... or even occasionally greatly enlarged for use on a billboard. But we viewed all those from quite a distance, many feet or tens-of-feet away! We weren't pixel peeping from 18 or 20", like we do today with our 100% image on our computer monitors today. On a typical monitor at native resolution, viewing an image from an 18 or 20MP APS-C camera at 100% is about like blowing it up to a five foot wide print - equal to around 60X or greater magnification - and then viewing it from 18 to 20" away!
jcboy3 wrote:
Ansel Adams shot medium and large format; with correspondingly smaller apertures required to achieve similar DOF.
Actually, Depth of Field (DoF) doesn't change with different formats alone. All other things being equal, it's exactly the same, regardless whether the camera is an APS-C digital or a 4x5 large format.
DoF changes depending upon aperture, focal length and distance.
However, what is true is that when we change format, in order to frame the subject the same way in practice we also have to either change focal length or distance to the subject... or a bit of both.
For example, approx. 30mm lens on an APS-C camera acts like a 50mm lens on "full frame" (24x36mm)... or a 75mm lens on 6x4.5cm... or 90mm on 6x7cm... or 180mm on 4x5". All those are roughly "standard" lenses on their respective formats. And the changes in focal length will cause a corresponding change in DoF, making it shallower as the focal length increases.
OTOH, if there were such a thing as a 30mm lens that could be utilized on all those formats, it would be a standard on the APS-C, act as moderately wide on full frame, or as a wide angle lens on 6x4.5 and 6.x7, and behave as an ultrawide on 4x5... and so long as you shot your subject from the same distance and with the same aperture, it would render exactly the same DoF on all of the formats. DoF would only change if you changed the lens aperture or moved closer to or farther from your subject with the camera and lens.
In practical application, the effect is actually just the opposite of what you suggest with your Ansel Adams reference.
The longer focal lengths used with larger formats make it "easier to blur down" a background. Or - alternatively - it's harder to achieve the same level of blurring with the smaller formats. Notice that for APS-C, "full frame" and 35mm film cameras there are quite a few lenses with f1.4, f1.8 and f2 apertures... even a few f1.2. In medium format systems, there are almost no lenses faster than f2.8, and even those are rather rare... More common medium format lenses are f3.5, f4 or slower. And, in 4x5 large format, it's almost unheard of for lenses to offer any larger than f5.6. Quite a few are only f8.
Yes, Ansel Adams tended to use pretty small apertures and longer exposures for his scenic shots. But he did that because he was looking for enough Depth of Field to render sharpness from foreground to infinity! He had a few 35mm and some medium format roll film cameras, but Adam's best known works were done with large format, sheet film 4x5, 5x7 and larger cameras. I shot quite a bit with 4x5 format in the past and with them often stopped down to f22, f32 and f45 for the same reasons. I also used medium format, but because I was more typically shooting portraits with those, would tend to use them closer to wide open.
BTW, Adam's also used the Zone System of metering, exposing and processing his images.... which today we might call "HDR". And his extensive notes show that when printing them, he did a whole lot of tweaking of his images... everything from his choice of paper and development chemistry to careful dodging and burning.... today we might call that "post-processing" or "Photoshopping". I suspect Ansel would have loved digital imaging!
Jun 3, 2016 00:20:56 #
did a sharpness test on 3 telephoto lens , a 400mm , a 500mm and a zoom 600/1000 .all 3 lenses at the lowest F stop had a noticeable lack of sharpness , close down 1 stop , and they are fine .almost same thing but not as bad at the highest F stop . that is nice to know , just dont shoot wide open .
Jun 3, 2016 00:41:41 #
folkus wrote:
When I Googled "Sharpest Aperture" I fou... (show quote)
Sharpness is just one aspect of a photograph and certainly not the most important. I tend to ready test charts on the different lenses that I own from places like Photozone or Camera Labs to see where the sweet spot of each lens is, it seems that for most of my lenses that is between f/4 and f/5.6, this is hardly a consideration when I make an image however, I am thinking about how much of the image I want in focus, or how will the aperture effect shutter speed and will I have to push the ISO to minimize blur or stop action at a particular aperture.
Here is a link to a test chart so you can see what I am talking about. You will find the resolution chart near the bottom of the page.
http://www.photozone.de/canon_eos_ff/877-canon_1635_4is?start=1
Jun 3, 2016 07:30:23 #
wj cody
Loc: springfield illinois
Blurryeyed wrote:
Sharpness is just one aspect of a photograph and c... (show quote)
"sweet spot" usually refers to tennis racquets!
Jun 3, 2016 10:00:03 #
wj cody wrote:
"sweet spot" usually refers to tennis racquets!
Only if you're with a tennis based group. It could be a golf club for those talking golf. It could be the best time to advertise on TV to get bang for the buck, similar to "prime time". It could be...
You get the point I hope?
As for usage with a photographic circle of friends, it "usually" is tagged with lenses not sports equipment.
Jun 3, 2016 10:37:31 #
sharpness of a lens is critical when you do wildlife photo , and you need to crop more then you would like , because the subject was far away .at wide open , the image fall apart fast , close up 1 or better 2 F stops , and you end up with a usable picture . that is it , nor really high tech . a world known astro photographer said that when you buy a pricey F1.2 lens , you wont be shooting at F 1.2 , but you will be using the next stop .
Jun 3, 2016 10:52:49 #
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