Diffraction versus satisfaction -

[autofocus]

Below is an email article I received about the often discussed, and somewhat controversial subject of diffraction...I thought it interesting and wanted to share with you. Remember, don't shoot the messager...lol

DIFFRACTION VERSUS SATISFACTION!

These past few months, the Q/A in many of our classrooms has been abuzz with concerns from our students about "shooting pictures at the aperture of f/16 or f/22."

Seems a couple of those "big" Photography Forum websites have unleashed some really OLD NEWS that when a lens is set to the smaller apertures, such as f/16 or f/22, lens diffraction is more noticeable; in laymen's terms, lens diffraction means a loss of contrast and sharpness.

I figured now is as good a time as any to set the record straight about 'lens diffraction' and want you to know that I am also speaking for all of the teachers here at the school. So without further ado, here is what we have to say-"Shooting at F/22 can be a GREAT IDEA!" Any worries about loss of sharpness and contrast are just as over-blown as the Y2K fears!"

In 35+ years of shooting commercially, I can't ever remember a time when a client said "Bryan, whatever you do, don't shoot at F/22" nor can I ever remember a single instance where either Getty or Corbis called me to say, "Bryan, DON'T send us any of your pictures for our stock files if they were shot at F/22." And the reason I can't remember is because it NEVER HAPPENED and it NEVER WILL!

The aperture of F/22 produces a massive depth of field, in particular when combined with a wide-angle lens. And IF you have any ounce of creativity in your DNA, you will want to strive to use some foreground interest in your overall composition, since it will be the foreground interest that will create the illusion of depth and subsequent respective in your composition. And the only way to record sharpness from front to back when using an immediate foreground is to use F/22, the smallest lens opening which in turn produces the greatest depth of field a.k.a. the greatest are of acceptable sharpness.

Photo 1: F22

Photo 2: F8

Both of these images were shot with the same lens, Nikkor 12-24mm at the 16mm focal length and they are both shot at the same exact exposure in terms of its quantitative value, but oh my, is there ever a noticeable in their overall sharpness. The first image was shot at the "dreaded" aperture of F/22 and the second image was shot at the "highly recommended aperture" of F/8.

I don't know about you, but we here at the school prefer the image taken at F/22 because it shows the overall area of acceptable sharpness that we really need to convey here-FRONT TO BACK! In the image taken at F/8 clearly, we don't have sharpness front to back! So, with the proof staring at you right on your screen, what do you think? Are you going to begin to embrace the use of F/22? You will if you have any intention of being a creative photographer, because quite simply, you will NEVER record the great foreground to background landscape shots unless you choose f/22!

Photo 3: F22

Photo 4: F8

And just for the record; these next two examples are the same shot of this very scene but at a 200% magnification. The difference between the sharpness in either shot is nil but I will be the first to admit that there is a wee bit more contrast in the bark of the tree with the shot taken at f/8, BUT again this is at a 200% magnification. This wee bit loss in contrast is also something that I and so many other discerning photographers can live with!

The long and the short of it; the question of using F/22 was NEVER an issue during the days when we all shot film and it should NOT be an issue today. Diffraction is a real event, but it should never get in your way of shooting those compositions that demand extreme depth of field. Satisfaction is your reward, so get out there and get creative at f/22!

[OsmosisStudios]

Sorry, but no.

I'll admit, there is alot of DoF available at f/22, but the testing method is flawed. For one, he uses 200% magnification as a standard: that's not at all the best way.

He's also comparing front-to-back changes, which are affected by DoF more than diffraction. In this case, the camera was likely focused to about 1/3 of the way into the scene to achieve maximum impact. The thing is, he then compares the item farthest away for detail. Of course the F/22 shot and f/8 shot are going to be similar: at f/22 the lens is in focus but diffraction makes it soft, and at f/8 the DoF makes the tree soft.

I'm calling shenanigans: terrible test.

[kencaleno]

First of all what focal length lens was used? Then we can work out the Hyperfocal distance to get everything in the frame sharp at each aperture-For instance if a 18-55mm kit lens was used, at the widest focal length (18mm),

At f22 the hyperfocal distance would be 0.754.3 meters,and depth of field would be from 0.375 meters to infinity.

At f8 the hyperfocal distance would be 2.04 meters-depth of field would be 1 meter to infinity. If we aren't told these specific details-the explanation is worthless crap

Regards, Ken

[FoG]

Like the Thirds rule .... it is more a guideline if it works use it if you wanna try something do so ... one thing I hate is people who think they can dictate what and what does not work in photography as it is an artform and therefore someone's taste is different to others.

Simply if it works for you in certain situatons USE it ! if not find something that does but why state it as a NOT to ?? silly (no offence to OP) as I know this was not their comment I just think some people seem to think they can dictate rules in art and we all know that is rubbish

[fletch]

Sounds like whoever wrote this is trying to stir up controvesy for its own sake where none exists. Here are the facts.

Difraction is real and is worse at very small apertures, this affects the sharpness of photos. DoF is greater at very small apertures which is usefull for capturing foreground detail.

Nobody worth listening to ever said don't ever use f/22, more use it only when you need it. If you can get the shot at f/16 or f/11 then don't use f/22. Simple as. All this example proves is that whoever wrote the article needs some extra trafic to whatever it is they are promoting via email.

[wulf]

Has anyone got (or fancies getting) a better series of test photos?

Wulf

[kencaleno]

Originally Posted by fletch

Sounds like whoever wrote this is trying to stir up controvesy for its own sake where none exists. Here are the facts.

Difraction is real and is worse at very small apertures, this affects the sharpness of photos. DoF is greater at very small apertures which is usefull for capturing foreground detail.

Nobody worth listening to ever said don't ever use f/22, more use it only when you need it. If you can get the shot at f/16 or f/11 then don't use f/22. Simple as. All this example proves is that whoever wrote the article needs some extra trafic to whatever it is they are promoting via email.

Seems like Bryan Peterson wrote it

[rediguana]

Originally Posted by someone ranting about diffraction

... And the only way to record sharpness from front to back when using an immediate foreground is to use F/22, the smallest lens opening which in turn produces the greatest depth of field a.k.a. the greatest are of acceptable sharpness... Are you going to begin to embrace the use of F/22? You will if you have any intention of being a creative photographer, because quite simply, you will NEVER record the great foreground to background landscape shots unless you choose f/22!

If someone is really serious about getting sharpness front to back, they aren't going to be using a standard lens with a plane of focus that is parallel to the sensor. They are going to be using a tilt-shift lens and they are going to lay the plane of focus right down where they want it i.e. on a plane running from the foreground to background. The fact that this photographer doesn't even mention tilt-shift lenses says something.

The real trick is making the decision as to whether shots greater than f8-f11 (depending on the size of your sensor) are worth it. If the added depth of field creates a better image even with a little diffraction then do it. But if the diffraction is going to ruin some of the fine detail, then it probably isn't worth it.

Also, good diffraction article here - TUTORIALS: DIFFRACTION & PHOTOGRAPHY

[wulf]

That is a useful tutorial - I particularly like the images (hover over the tables and watch the pictures change according to the settings).

Wulf

[vandergus]

Well, the methodology of the article may be a little flawed but the point is valid. Sometimes it's better to trade critical sharpness in part of the frame for slightly less sharpness over the entire frame. I could see why, when talking about diffraction, that some people would assume you should never stop down past the diffraction limit of the lens/sensor combo. This is just a friendy reminder that in some cases, f/22 is a better choice than f/8.