DP3M lens relatively soft at f11 and f16 ... with examples.

[Keith]

So obviously it's been proritized for wide open shooting which seems a little unusual for this type of camera to me.

These were shot from a tripod yesterday and aside from the crops are unaltered from the raw files. Just converted to 16 bit TIFFs then to resized jpegs for web viewing. The tower I isolated is about twenty ks away and it was a little on the hazy side when I took the pics.

I guess resolution is a realtive thing and it's not really the way I use the camera anyway ... It was purely an exercise in curiosity. The lens appears to be at it's worst at f16 and not a lot better at f11, it starts to improve considerably at f8 and to my eyes seems to be at it's best from f3.5 to f5.6. I would liked to have tried f2.8 but it was too bright for the shutter speed max of 1250.


Original

and the crops

 

[jonmanjiro]

Nice example of diffraction and how good the lens actually is! It's fairly easy to see the effect of diffraction now that we have 100% crops to scrutinize 🙂

 

[DamenS]

Nobody escapes the laws of physics ! The (supposedly amazing) lenses on the new Sigma range are probably getting fairly close to being diffraction limited.

 

[jonmanjiro]

The resolution decreasing as the lens is stopped down actually means the lens is diffraction limited i.e. diffraction is the limiting factor to resolution.

Looks like its best to shoot the camera stopped down no further than f/5.6 for best results!

 

[bonatto]

Keith, just saw your DP images on Flickr, fantastic, might have to give sigma another try!

 

[dfatty]

nice example, definitely can see a difference. the amount of detail in the f3.5 is insane considering one can barely see the tower in the full size pic.

 

[redisburning]

f8 hasnt been the sharpest resolution of a fine lens since the 1970s outside of really extreme designs.

in fact, Id rather focus stack today's lenses at f4 than use f8 if I can get away with it.