I took this with my Nikon DSLR about a month ago. Today I was going through the photos and was just about to delete this otherwise unremarkable picture when I noticed a large artifact over the image of my wife's iPhone. It looks like a reflection. Is it coming from the camera, sensor, lens? What do you think?

enter image description here


Looks like a pattern created by the 2D diffraction grating. In the case of a smartphone screen, the individual pixels form the rectangular array, exactly like how the typical 2D grating is built. The effect can be more or less visible depending on the specific screen technology and pixel density.

from Plymouth Grating Laboratory: 2D diffraction pattern

  • Would it be visible to the naked eye, or is it an interaction of the grating on the phone's screen with the grid of the sensor of the camera that took the photo?
    – Michael C
    Feb 1 '19 at 14:13
  • Very cool. Interesting what conditions made it visible.
    – Blago
    Feb 1 '19 at 14:14
  • I tried several, mostly older screens and the full pattern was only visible in iPhone 6. some screens only showed 1D diffraction (a line of rainbow points) and in the others there was only a glare and nothing more.
    – szulat
    Feb 1 '19 at 17:20
  • @MichaelC yes, it is visible to the naked eye!
    – szulat
    Feb 2 '19 at 0:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.