Small apertures
Feb 11, 2023 08:59:16 #
I see many articles and much discussion here about diffraction with small apertures.
If diffraction is so destructive (Easily shown in review examples) then why do modern lenses for digital cameras still have small apertures such as f11, 22, 32 etc?
Would not changing shutter speed, ISO or a ND filter be better?
Just was reading a review where this came up again and the question occurred to me as to why these small apertures exist any more.
Thank you to the experts who can explain the justification of sacrificing quality by using smaller apertures or if there is a work around , excluding software faking it.
If diffraction is so destructive (Easily shown in review examples) then why do modern lenses for digital cameras still have small apertures such as f11, 22, 32 etc?
Would not changing shutter speed, ISO or a ND filter be better?
Just was reading a review where this came up again and the question occurred to me as to why these small apertures exist any more.
Thank you to the experts who can explain the justification of sacrificing quality by using smaller apertures or if there is a work around , excluding software faking it.
Feb 11, 2023 09:01:35 #
I use small apertures for great DOF in landscapes and get excellent results, especially after applying Topaz sharpening in post.
Feb 11, 2023 09:05:27 #
Blurryeyed wrote:
I use small apertures for great DOF in landscapes and get excellent results, especially after applying Topaz sharpening in post.
In other words adding fake manipulations through software.
That was part of the question.
Feb 11, 2023 09:16:34 #
I have generally used an aperture of f16 for macro photography and have never noticed any diffraction. Yes, I have heard it can be a negative but I have not seen it OR don't know what to look for. But apparently if it was so bad I would have noticed something negative over the years.
Dennis
Dennis
Feb 11, 2023 09:28:08 #
dennis2146 wrote:
I have generally used an aperture of f16 for macro photography and have never noticed any diffraction. Yes, I have heard it can be a negative but I have not seen it OR don't know what to look for. But apparently if it was so bad I would have noticed something negative over the years.
Dennis
Dennis
Feb 11, 2023 09:32:13 #
Architect1776 wrote:
In other words adding fake manipulations through software.
That was part of the question.
That was part of the question.
Well, we all work with our cameras and I have not noticed any terribly distracting "diffusion" even when shooting at f/22, but I do use sharpening as part of my workflow probably when not even needed. Photography is more about capturing a feeling or an emotional response than it is about tac sharp images, unless you are doing Macro work. Personally I have always considered aperture settings to be one of the most creative mechanical controls in photography, from portrait to landscape I don't think that anybody should be afraid to use just about any aperture setting.
Feb 11, 2023 09:37:08 #
When you increase DOF, the extra detail that's captured is large scale. Background stuff and possibly foreground stuff that would have been blurred out is rendered clearly and accurately. In that scenario the microdetail isn't as relevant as the large scale detail so the loss of microdetail is perceived as being acceptable.
It seems to me that most of the time a loss of microdetail won't even be noticed unless there is some way to do a side-by-side comparison of the shot with and without microdetail - which won't happen most of the time. In other words most of the time we won't notice any loss of microdetail unless it's extreme. That won't happen except with very small apertures.
It seems to me that most of the time a loss of microdetail won't even be noticed unless there is some way to do a side-by-side comparison of the shot with and without microdetail - which won't happen most of the time. In other words most of the time we won't notice any loss of microdetail unless it's extreme. That won't happen except with very small apertures.
Feb 11, 2023 09:38:51 #
Feb 11, 2023 09:50:20 #
I was working on some old images just yesterday where I had found some smaller aperture (f/32) images. The novice shooting those in 2010 (me) didn't know what I was doing. The more experienced me could look at identical versions and see the loss of fine details throughout the image, as well as the need to clone-out sensor dust that was not evident in the frames from the same camera moments earlier at a more practical f/11.
Photographers everywhere would be better served by lens manufactures if they would implement a 'hard stop' at f/18 on all lenses that can be mounted to modern digital cameras. This will save those that don't (or refuse to) understand diffraction from making mistakes with their aperture selection.
Photographers everywhere would be better served by lens manufactures if they would implement a 'hard stop' at f/18 on all lenses that can be mounted to modern digital cameras. This will save those that don't (or refuse to) understand diffraction from making mistakes with their aperture selection.
Feb 11, 2023 09:57:27 #
Architect1776, you are spot on that diffraction is a function of the lens aperture setting and resulting depth of field. It is also a function of the lens magnification and the effect of the two in combination that results in the bending of the wave of light passing through the aperture. The two work together to produce what is referred to as the "effective aperture" which creates a result different than that marked on the barrel of the lens. Let's keep in mind that the bending of light waves through an aperture is obedient to the physical laws of light.
We define it this way:
DOF (measured in millimeters) = (0.0022*N*N)/(m*m), where N is the F-number and m is magnification.
Attached is a spreadsheet that equates the indicated f/stop and the effective f/stop based on the lens magnification.
It is likely that landscape and portrait lenses have quite low magnification so they are less affected by visible diffraction compared to a 5X macro lens used as the optic for the camera.
We define it this way:
DOF (measured in millimeters) = (0.0022*N*N)/(m*m), where N is the F-number and m is magnification.
Attached is a spreadsheet that equates the indicated f/stop and the effective f/stop based on the lens magnification.
It is likely that landscape and portrait lenses have quite low magnification so they are less affected by visible diffraction compared to a 5X macro lens used as the optic for the camera.
Feb 11, 2023 10:07:58 #
Strodav
Loc: Houston, Tx
There is nothing like proving it for yourself with your own gear. When I first read about using small apertures in Landscape Photography for increased DOF (Bryan Peterson's Exposure Solutions), I tried it with a sequence of shots from wide open to f/22. Guess what, for my gear I started seeing a softening around f/11. Now I focus stack using 3 to 5 shots and get a better result.
Feb 11, 2023 10:08:48 #
sippyjug104 wrote:
Architect1776, you are spot on that diffraction is... (show quote)
So doing macro, where I want max DOF, I screw up the sharpness trying to get the greater DOF.
That sucks if you know what I mean.
Thx for the chart.
Feb 11, 2023 10:23:04 #
Another point - softness due to diffraction will in most cases be easier to fix than softness due to a lack of DOF. When difficult circumstances force some kind of compromise, small apertures will give you more of what you want. It's better to have that option rather than no option.
Feb 11, 2023 10:27:03 #
CHG_CANON wrote:
I was working on some old images just yesterday wh... (show quote)
A "hard stop"??? I hope you aren't serious! Unless your definition of 'hard stop" is different from mine? I make "mistakes" with my aperture selection all the time. And will continue to do so!
Feb 11, 2023 10:33:51 #
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