Kuzano

Beer causes diffraction of reading comprehension. Less sharp! :-P

NormanHarley Loc: Colorado

I think I've got it now! Beer for diffraction, and coffee for sharpening! :thumbup:

jeep_daddy Loc: Prescott AZ

Everybody seems a little touchy this morning. Have another cup of coffee and have a nice day.

ssymeono Loc: St. Louis, Missouri

Remembering the "64-club" of the old film days when pros used the smaller aperture for landscapes, I wonder whether "small aperture diffraction" affects both film and digital or is strictly a problem of the latter.

ballsafire Loc: Lafayette, Louisiana

Jeep Daddy - can call the faux pas! :thumbup: :thumbup: :thumbup:

Apaflo Loc: Anchorage, Alaska

It's all the same... for any given size of sensor!

And using an 8x10 or 11x14 view camera is a little different than a 36x24mm frame. My math on this may not exact, but I'd expect that if a 35mm becomes diffraction limited at f/22 an 8x10 is probably diffraction limited at about f/90.

Hence the f/64 club folks were pushing it, but were within a reasonable range.

lamiaceae Loc: San Luis Obispo County, CA

DIFFRACTION. Explained by Quantum Mechanics. There are a number of good WEB sites about it and for various lenses and sensor formats and pixel counts and pitch sizes. Technical stuff.

rehess Loc: South Bend, Indiana, USA

The math hasn't changed. However, people weren't nearly so focused on sharpness back then, and seemingly more aware of DOF.

Before I moved into digital photography, I had a pro scan some of my old 35mm Kodachrome 25 slides; after setting up my computer and a projector/screen so I could compare images to slides, I discovered that every detail visible on the slides were also visible on the (6mp) images. At one time, I wondered if that was an artifact of my lenses. However, recently I mounted my 1984 50mm lens (the one I used in taking some of the Kodachrome 25 pictures in the comparison) on my 16mp Pentax K-30, and I discovered that it was at least as sharp as the lenses I use now, so I'm becoming convinced that the comparison was valid, that the digital age has simply caused us to become addicted to more sharpness ( which is why I tend to use the term "needle sharp" instead of "razor sharp" ).

As usual, there are tradeoffs. A smaller aperture, to get more DOF, will always require slower shutter speed and/or higher ISO setting; beyond some point, getting that greater DOF will cause some detectable diffraction. Fortunately, with digital photography, experimenting costs nothing monetarily (but will of course cost time), and feedback is very fast, so the best course is probably to experiment with the photo equipment you have and then decide for yourself which combination of settings is most pleasing to you, taking your style of photography and your way of looking at pictures into account.

NormanHarley Loc: Colorado

I have reduced my flash power now and am back to f/8. Much happier with the quality of the images in spite of the loss of depth of field. I guess I will quit trying to use my flashes as a bug zapper! :thumbup:

(Download)

lamiaceae Loc: San Luis Obispo County, CA

Yes, seriously. Photography is only a tiny aspect of what is and is affected by diffraction. And to really understand it you have to step back and look at the history of physics and quantum mechanics especially. True, in the practical sense diffraction can be a major problem in macro-photography, after realizing how much it affects digital photography and macro especially, I started laying off using f/16, f/22, and f/32. I plan to try using image stacking in the future. Seems it was less an issue with film, but still a limiting factor. But to understand what diffraction is, you have to step way outside of photography.

rehess Loc: South Bend, Indiana, USA

Reduced DOF is not necessarily a bad thing, since it focuses the observer's attention on the main subject of your photograph. A few years ago I took a picture of a dragon-fly on a line; the dragon-fly and line were sharp, but the trees in the background were just part of the bokeh (the trees would have been very distracting if they had been in focus).

NormanHarley Loc: Colorado

I have the free download CombineZP stacking program. Most of my subjects just don't want to pose long enough for me to get enough to stack, though. I am slowly figuring out the best settings and lighting for my camera and lens combination. Practice practice experiment and practice! :thumbup:

NormanHarley Loc: Colorado

Would love to see that dragon! Feel free to post it here if you still have it.

ssymeono Loc: St. Louis, Missouri

This is very interesting that digital made us more aware of sharpness! Is it also true that diffraction is less noticeable but still present in distant landscapes than macro-photography at f/16-22? Even when DOF is nearly perfect?

rehess Loc: South Bend, Indiana, USA

This is the best version I can find right away. It was scanned from film by the processor in the days when I was transitioning to digital.

I recognize this is not a great example. I should have gone with a smaller aperture, because even his tail is slightly out of the DOF, but between getting shutter speed that would stop his motion and not being able to switch to a faster film, this is what I was able to get.

dragonfly at Jamestow VA - 2004

(Download)