I've noticed, especially in long-exposure city lights photos, that strong light sources are surrounded by rays. The number of rays seem to depend on the lens being used. What causes these rays and the ...
When we say a light source emits 1500 lumens of light, it does not really matter if the light source is incandescent, CFL, diode etc. Similarly, when I say f/1.8 can I assume that all lenses pass the ...
See for example this photo: From my experience, the longer the exposure the stronger can this effect be observed. Is this correct? Are there any other factors that influence the creation of these ...