This is a continuation in a discussion of spatial frequency response (SFR) and modulation transfer function (MTF) testing reproduciblity. The series starts here: Towards a reproducible MTF testing protocol A reader suggested that I reconfigure my testing protocol to move the razor blade target rather than the camera. That approach has several advantages: The target… [Read More]
Archives for 2016
MTF testing & lighting
This is a continuation in a discussion of spatial frequency response (SFR) and modulation transfer function (MTF) testing reproduciblity. The series starts here: Towards a reproducible MTF testing protocol The basic lighting technique that I’ve been using for my razor blade MTF testing has been to backlight a piece of white paper with two LED… [Read More]
MTF testing & vibration
This is a continuation in a discussion of spatial frequency response (SFR) and modulation transfer function (MTF) testing reproduciblity. The series starts here: Towards a reproducible MTF testing protocol A reader brought up the subject of vibration and its effect on SFR testing. I suppose we should deal with that sooner rather than later…. [Read More]
Towards a reproducible MTF testing protocol
There has been a little interest in developing a protocol for slanted edge modulation transfer function (MTF) testing that is sufficiently standardized and reproducible that the results from various amateur practitioners can be compared fairly. There are several things that conspire to make slanted edge MTF testing irreproducible: Alignment errors Field curvature Target differences Lighting… [Read More]
Aliasing at 42 MP with a sharp lens
After seeing the aliasing and false color with the Otus 85 wide open on the Sony a7RII in yesterday’s post, it’s reasonable to ask how much the lens aberrations at f/1.4 are reducing aliasing and false color, even if it’s obvious that they are not eliminating them. To do that, we can look at a… [Read More]
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