12-25-2011, 08:48 AM
[quote name='Plochmann' timestamp='1324794477' post='14086']
I am very confused by this statement post in the fourthird section by photozone. "Please note that four-thirds cameras have a different diffraction characteristic than APS-C or full format cameras. The real-world sweet spot, the point of highest resolution, is generally around f/4. Therefore it's hardly possible to improve the performance by stopping down when using (such) slow speed lenses. Remember that f/8 on a four-thirds camera is comparable to f/16 on a full format camera." (for depth of field, but also for sweet spot too?)
[/quote]
The sentence says "generally". Your are, of course, right that there is also a lens specific aspect in there. However, when looking at the MTFs of the slower lenses you may notice that the center performance is often best at max. aperture. The border performance and contrast may still improve a little when stopping down a tiny bit.
As far as the depth-of-field aspect is concerned - f/4 on MFT is f/8 on a full format camera so you may have to ask yourself whether you really need to stop down much further than this anyway.
I am very confused by this statement post in the fourthird section by photozone. "Please note that four-thirds cameras have a different diffraction characteristic than APS-C or full format cameras. The real-world sweet spot, the point of highest resolution, is generally around f/4. Therefore it's hardly possible to improve the performance by stopping down when using (such) slow speed lenses. Remember that f/8 on a four-thirds camera is comparable to f/16 on a full format camera." (for depth of field, but also for sweet spot too?)
[/quote]
The sentence says "generally". Your are, of course, right that there is also a lens specific aspect in there. However, when looking at the MTFs of the slower lenses you may notice that the center performance is often best at max. aperture. The border performance and contrast may still improve a little when stopping down a tiny bit.
As far as the depth-of-field aspect is concerned - f/4 on MFT is f/8 on a full format camera so you may have to ask yourself whether you really need to stop down much further than this anyway.