I’ve been struggling with the best way to present two aberrations at a time, and I think I’ve arrived at something pretty good: The above plots the point spread functions (PSFs) at the lower right corner of the simulated frame. The rows and columns are labeled with the aberrations employed. The diagonals show the aberrations… [Read More]
Archives for July 2025
Animations of transfocal behavior with lens aberrations
This animation comes from a Lens Simulator that I wrote using Matlab. In it we see nine Siemens star renderings at nine different locations in the frame. I used 31 wavelengths for the simulation, at 10 nanometer spacing from 400 nanometers throught 700 nanometers. The focus plane is moved in 0.1 micrometer steps from -8… [Read More]
The relationship of defous and spherical aberration
Consider the following grid: What you’re looking at is point spread functions from my lens simulator on the lens axis. Defocus occurs across the rows, with the red square marking the nominally-focussed points. Spherical aberration (SA) changes from the top to the bottom, with the value of the SA for each below that row. The… [Read More]
Combining aberrations — defocus
In my last post, I showed how individual optical aberrations affect image quality by presenting simulated point spread functions and Siemens star renderings with one aberration at a time. This approach makes it easy to isolate and understand the signature of each aberration. But lenses rarely suffer from a single imperfection. More often, multiple aberrations… [Read More]
Visualizing lens aberrations, one at a time, revisited
I have now constructed a more accurate lens simulator than the one I talked about last month. The new one takes phase effects into account, and uses 31 wavelengths between 400 and 700 nanometers on 10 nanometer spacing instead of three wavelengths. This is the first post with images from the simulator. When analyzing the… [Read More]