As the optical characteristics on lenses vary, there are different optimal aperture/f-number of each lens for obtaining peak performance(both contrast and resolution) on center, corner and extreme corner.
For eg, a lens with fast f/1.4 might not give peak performance at f/1.4, but stopping down to f/5.6 may give excellent center, corner and extreme corner contrast and resolution. Then further stopping down will just gradually go downhill due to diffraction.
Usually i refer to reviews on lenses, MTF charts etc. But i think it's better to get real world sample images and real world experience as taking photos isn't just about comparing charts and doing carefully-controlled tests.
In my opinion, with this knowledge we will be able to manipulate the characteristics of each lens to obtain the exact effect we want in our photographs.
So lets share our experiences on the lenses we have so that we have a simple database which both new and old pentaxians can refer to as a guide to get the maximum out of the lenses.
For eg, a lens with fast f/1.4 might not give peak performance at f/1.4, but stopping down to f/5.6 may give excellent center, corner and extreme corner contrast and resolution. Then further stopping down will just gradually go downhill due to diffraction.
Usually i refer to reviews on lenses, MTF charts etc. But i think it's better to get real world sample images and real world experience as taking photos isn't just about comparing charts and doing carefully-controlled tests.
In my opinion, with this knowledge we will be able to manipulate the characteristics of each lens to obtain the exact effect we want in our photographs.
So lets share our experiences on the lenses we have so that we have a simple database which both new and old pentaxians can refer to as a guide to get the maximum out of the lenses.