This is a continuation of this post: Off-axis aberration testing — Sony 12-24/4 on a7RII If you got here without reading the previous post, you should go back and do so now. Here is the full frame at 18 mm:   Here’s our magnified tight crop of the center, with the same pixel dimensions as before:… [Read More]

This is a continuation of the development of a simple, relatively foolproof, astigmatism, field curvature, and field tilt test for lens screening. The first post is here. I’m trying to refine my off-axis test procedures with the idea of getting them posted in a single document and inviting users to try them out. I’m sure… [Read More]

Yesterday I posted a series of images of foliage as captured by a simulated camera with fill factors varying from 1% to 100%. The aliasing artifacts of the low-fill-factor images were remarkably hard to spot. Today I’m going to do the same thing with a more demanding subject. Here it is, downsampled for the web:… [Read More]

I’m going to set aside the development of the lens test using the SIemens Star target to explore something that came up in the last few days while I was messing around with the camera simulator: the effect of fill factor on sharpness and aliasing. The reason why this is topical is the Fujifilm GFX… [Read More]

This is a continuation of  —  and a sidebar to — the development of a simple, relatively foolproof, astigmatism, field curvature, and field tilt test for lens screening. The first post is here. I took the simulator and set it up for a camera with a 5.3 um pitch, 60% fill factor, and a diffraction-limited lens…. [Read More]