Diffraction Calculator

I explain where the idea for this calculator came from: comparing the size of the Airy disk with the sensor’s pixels, where demosaicing means a point of light can cover about three pixels before diffraction shows. Then I pick a camera, a filter, and an ƒ-stop row to show how the table shows you whether diffraction will be visible. Read the post.

Diffraction in Digital Infrared Photography

What diffraction is, and the three things that control it: ƒ-stop, wavelength, and pixel size. I compare a Fujifilm X-T2 in visible light with an X-T20 converted to 590 nm, adding 720 and 850 nm filters, from ƒ/2 to ƒ/16 with the same lens. The sharpest apertures were ƒ/5.6 to ƒ/8 in visible light, ƒ/4 to ƒ/5.6 at 720 nm, and ƒ/4 at 850 nm. Read the post with the test images.

Sharpest ƒ-stop? GFX 50S Diffraction Test

I test every aperture on a full spectrum Fujifilm GFX 50S with the GF 45 mm lens, through a hot mirror, IR Chrome, and 550 to 850 nm filters. The sharpest ƒ-stop was ƒ/11 with the hot mirror and IR Chrome, ƒ/8 from 550 to 720 nm (ƒ/5.6 to ƒ/8 with a Hoya R72), and ƒ/5.6 at 830 and 850 nm. Read the post with the full results.