Why do the following two lenses provide different amount of light? In both images we have fixed focusing distance, distance to the object, ISO, shutter speed and F-number.
T-stop measures actual light transmission in a lens. Therefore, different f/2.8 lenses can have different T-stops. T-stops are usually only given for cine lenses. For photography lenses, is there any ...
Do lenses with the same f-stop but different focal length gather the same amount of light? [duplicate]
I'm taking images of a light source in a scientific labratory, and I thought I had a good grasp on all these things, but now i'm second guessing myself after some results. The most important thing is ...
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 ...