Back when I was in high school physics class, the teacher taught us to analyze the dimensions involved in any problem we were trying to solve before plugging in the numbers and grinding out the calculations. If the dimensions weren’t right, you’d set up the problem wrong, and no amount of fancy calculus (this was… [Read More]
Archives for 2015
Focusing the D810
In the last few posts, I’ve been dealing with my problems in achieving precise, repeatable critical focus with the Nikon D810, which doesn’t have focus peaking. In an attempt to add focus peaking, I hooked an Atomos Shogun monitor/recorder to the HDMI output of the D810, and turned focus peaking on. Close, but no cigar…. [Read More]
Real-world sharpness — what to do?
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]
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]
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