With a lens this good, the real question is. “At what f-stops is the lens diffraction-limited.?” I thought I’d try to find out. The motivation is to get some insight into how close real photographic lenses are to being diffraction-limited, and thus learn whether or not the concept of Imaging System Q, which I’ve been… [Read More]

I processed a reduced-contrast version of the ISO 12233 target, with white point of 200 and black point of 55, through the camera simulator of the last post. To review, here are the specs of the simulated camera. Perfect, diffraction-limited lens set at f/8. 550 nm light used to calculate diffraction, even for the red… [Read More]

In the preceding few posts I explored imaging system Q, a metric for imaging system balancing. It was developed for use with monochromatic sensors and diffraction-limited optics, a luxury not enjoyed by most normal photographers. I explored the extension of the metric to cameras with Bayer color filter arrays (CFAs), with inconclusive results. In order… [Read More]