I’m been floundering around all day trying to tease out lens sharpness from vibration-induced motion blur in my test shots. This afternoon, the answer finally came to me. Make all the exposures in an aperture series using a strobe for illumination. I set up a Nikon D4 with the Zeiss 100mm ZF macro lens. I… [Read More]

I took a Nikon D4, mounted the 105mm f/2.8 Nikon G ED lens, turned off VR, and mounted it on a RRS TVC-34L Versa Series 3 tripod and a RRS BH-55 ball head. I extended the top two leg sections, but not the bottom one. I left the column in the down position. My first… [Read More]

Well, I thought I was done with the preliminaries, but it occurs to me that the standard deviation is going to vary linearly with exposure. I wrote some code to check that and correct for it. Then I came up with a way to simultaneously correct for overall exposure variation, and exposure variation caused by… [Read More]

Before I deal with all the uncontrollable and semi-controllable variables involved in making actual test photographs, I did some simulation to make sure the target would work the way I thought it would under completely controlled, albeit unreal, conditions. I wrote this Matlab script: I ran it, and plotted the results. As expected, more low-pass… [Read More]