Guide to Cameras

[davidc]

I wondered if you would use that example. It's the only one I've seen you ever use For m43 it's not bad.

Still though, it's quite a compromise - that 56mm f1.2 would give the same bokeh as an 85mm f2.4, quite a difference. But as I say, for things like landscapes and still life it's not really going to affect you - I understand your decision to not be worried about it

Diffraction is a more seriouss issue though. Trying to find sources to back up the f/7 suggestion, it's a bit worse than I first feared - it actually starts at f5.6. The rule of thumb is that it becomes a problem that visibly reduces shot quality 2 stops after it manifests, meaning f8 for m43 and f16 for FF. I've obviously not tested myself but based it on numerous sites (dpreview, ming thein, steve huff were three I found tonight that had numeric answers).

Then again, maybe these two things counteract each other - you lose the ability for creamy bokeh but get correspondingly greater DOF so for your landscapes you don't need to go to f8, you can stay around f5.6.

I think we've probably covered the pros/cons ourselves of FF vs m43 several times over now.

[Mike Farley]

I wondered if you would use that example. It's the only one I've seen you ever use For m43 it's not bad.

High praise indeed.

Diffraction is a more seriouss issue though. Trying to find sources to back up the f/7 suggestion, it's a bit worse than I first feared - it actually starts at f5.6. The rule of thumb is that it becomes a problem that visibly reduces shot quality 2 stops after it manifests, meaning f8 for m43 and f16 for FF.

Since when was f/8 TWO stops slower than f/5.6? Since when was f/16 TWO stops slower than f/5.6? By your argument, the critical point is f/11.

My advice? Stop worrying about diffraction, don't stop down too much if you can and just shoot. So what if the shot is not optimally sharp? Better that than no shot at all. ("Oh no, I cannot take that shot of a lifetime because my aperture is too small." ) Didn't you say on here a while back that sharpness is a bourgeois concept?

viewtopic.php?f=2&t=1283&hilit=bourgeois#p6153

[Mike Farley]

I wondered if you would use that example. It's the only one I've seen you ever use For m43 it's not bad.

High praise indeed.

Diffraction is a more seriouss issue though. Trying to find sources to back up the f/7 suggestion, it's a bit worse than I first feared - it actually starts at f5.6. The rule of thumb is that it becomes a problem that visibly reduces shot quality 2 stops after it manifests, meaning f8 for m43 and f16 for FF.

Since when was f/8 TWO stops slower than f/5.6? Since when was f/16 TWO stops slower than f/5.6? By your argument, the critical point is f/11.

My advice? Stop worrying about diffraction, don't stop down too much if you can and just shoot. So what if the shot is not optimally sharp? Better that than no shot at all. ("Oh no, I cannot take that shot of a lifetime because my aperture is too small. Fame and fortune will elude me forever" ) Didn't you say on here a while back that sharpness is a bourgeois concept?

viewtopic.php?f=2&t=1283&hilit=bourgeois#p6153

[davidc]

Oops sorry, I crossed numbers there. f/5.6 it starts, f/8 it's visible and f/11 it's hampering image quality (and f/11 > ff/16 > f/22 for full frame, though in my experience f/22 is too far and I pull back 1/3 or 2/3 depending on the scene). I felt it important/worth highlighting that for an m43 f/2.8 lens, by way of an average, you get two stops before diffraction hits, three stops useable and after that no matter the shot it'll be noticeably blurry. For me, that's a big deal. I noticed the issues myself on the 550D where the DLA is higher than an m43, but not by much. Still, f/8 was fine and f/10 often perfectly ok depending on the scene. I really noticed it after that though.

Sharpness indeed is often overrated but there's context to consider, such as the difference between trading sharpness for usability in one camera system and never being able to get something sharp beyond f8 because of the limits of physics in a different camera system. I'd like to at least know the limits of my kit before I buy. Which was the point of highlighting it alongside other pros/cons.

I don't really feel like this ongoing debate is adding much value anymore though. I'll also be away from the forum for a while, sorry if I have offended or upset anyone.

[Mike Farley]

.... sorry if I have offended or upset anyone.

No worries here. Enjoy your break.