Lenses and Optics
We all know that aberrations affect points of light off-center, making them blurred. We all know that some aberrations are worse the farther away from center we go. And we know that some aberrations are improved when we reduce the aperture. Some of us even know the various rules-of-thumb for what makes an aberration […]
Equipment
This is a Geek Article, with very little practical information. But there are pretty pictures that non-Geeks might like. (Not the construction pictures, the ones further down.) First, I should explain why I haven’t posted much lately. Lensrentals was able to expand into some adjacent space, which was desperately needed. But the testing and repair […]
Equipment
First and foremost, if you aren’t at least a little Geeky, this post is not for you. Unless you’re one of those people who thinks ‘just take some pictures, dammit’ when I write some article about resolution testing. In that case, you might like this article because we’re taking pictures to test lenses. Sort of. […]
Lenses and Optics
Sigma has been releasing one great lens after another for a while now. Some, like the 35mm f/1.4 and 18-35mm f/1.8 zoom, have created feeding frenzies soon after (or even before) their release. Others, like the 24-105 f/4 OS, haven’t created a whole lot of fuss. So I thought we would do a little optical […]
Lenses and Optics
OK, I’ve done a couple of posts about critical focus for testing, and setting up an optical testing station. This post will provide some demonstrations about actually using it. I’m going to use lenses that we optically adjusted back into proper alignment as examples. I’m doing this because it’s a great opportunity to show you […]
