Archives for August 2017

This morning I dropped by the Hartnell College Gallery to see the installation for my exhibition, This Green Growing Land. It’s a wonderful space, and I’m happy to have the unexpected opportunity to show this work again, about 15 years after its first showing in the same space.    Here’s a shot with the lights on, which… [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 getting ready to wrap all these posts on lens screening up into a paper that describes an entire lens test procedure, but there are a few things… [Read More]

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]