If some portion of light from the scene is diverted to the AF system, does this reduce the light to the main sensor in any meaningful way? Would cameras with AF have perceptibly more noise in low-light situations?
f16falcona46
On DSLRs, you can only autofocus while your mirror is down. When you're actually capturing the image, your mirror is up, so it doesn't take any light away (but also can't focus).
If some portion of light from the scene is diverted to the AF system, does this reduce the light to the main sensor in any meaningful way? Would cameras with AF have perceptibly more noise in low-light situations?
On DSLRs, you can only autofocus while your mirror is down. When you're actually capturing the image, your mirror is up, so it doesn't take any light away (but also can't focus).