Archives for June 2025

Here are the aberrations in the same strength as in the last post applied to a different base image.                

In the last post, I showed you the result of several common lens aberrations taken one at a time. In this post, I’ll do the same for a photographic image. See the previous post for explanation and definitions.              

I’ve written a program to simulate lens aberrations, singly and in combination. For some of the limitations of the program, see the preceding post on this blog. In this post, I’ll use a grid of sinusoidal Siemens stars as the target. Later on, I’ll show results on real-world images. This post presents the main aberrations… [Read More]

For the past couple of weeks, I’ve been working on a simulator to assist in visualizing the effects of lens aberrations. In the interest of computing speed and programming effort, I’ve had to make a lot of compromises, but I hope it will be useful. I’ll be presenting results soon, but first I’d like to… [Read More]

Photographers often talk about exposure. It is one of the most familiar concepts in photography. But there is another important idea that hides just behind the curtain: the total amount of light that lands on your sensor during an exposure. Understanding the difference between exposure and total light can clarify a lot of confusion about… [Read More]