Tagged Questions
15
votes
2answers
402 views
Does a specific f number across all lenses denote same amount of light?
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 ...
32
votes
4answers
6k views
Why do light sources appear as stars sometimes?
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 ...
