Yesterday I talked about the impediments to getting, in real world situations, all the sharpness that our best cameras and lenses can deliver. Focusing, diffraction, depth of field, internal and external camera vibration are at the top of the list, and the situation will get worse as better lenses and higher-resolution cameras hit the streets…. [Read More]
Archives for June 2015
Sharpness in the real world
A reader — thanks, Chris! — made a comment yesterday that I think raises some points worthy of attention. So what needs to change in the camera, presuming the sharpness is in the OTUS , to get it out? Physics says f4 and that’s not changing soon, unless we hear from the Large Hadron Collider…. [Read More]
(Im)Precise focusing with Nikon D810 live view
In several days of trying, I can’t focus the Nikon D810 accurately enough for the focus error standard deviations to be less than the repeated exposure standard deviations. The first thing I tried was to change the target from a Siemens star to a combination of the star and a zone plate: You can’t see… [Read More]
Testing high res camera/lens sharpness across cameras
I’ve been reporting on the results of testing sharpness, as measured by MTF50 results from slanted-edge testing with the Otus 55/1.4 on the Nikon D810 and the Sony alpha 7R (a7R). For the last few days, I’ve posted nothing. That hasn’t been because I’ve stopped working. It’s been because I haven’t been able to produce… [Read More]