Wait, I don't get those ISO ideas at all. If we have two lenses that are f2.8, but one is is t2.8 and the other is t4 (for sake of argument), the camera would just choose a higher ISO or longer shutter to match the same EV, the same histogram curve. So you would end up with the same image, just different metering/settings. I mean, if the lens is darker, than the metering wouldn't know whether its lens or light conditions, so it would choose the settings that would give the desired overall EV. One lens and another would only expose differently if you were in M mode and kept the same shutter, aperture, and ISO. Then t4 would produce a darker image. But it would only bring more noise if you chose to set a higher ISO, or use PP to brighten it. Neither of these is affected by lens. The only way a lens could affect noise directly is if one lens would be radioactive to the point that it would affect the sensor (unlikely, I don't think thats how physics work) or if it would block incoming noise from outside of the camera. These two are both based on the premise that outside things can affect the noise performance. Now, maybe heat can affect noise, but this is usually ambient heat and sensor-generated heat, so again the lens would have next to no effect.
I am curious about this, maybe someone can link to research or an article. I did in the past think that some lenses are a little noisier than others, but I think that was just before I understood EV and didn't know that the f4.5-5.6 lens would use a higher ISO than the f2.8 lens in the same ambient light
Originally posted by vcollerp A few of my first ones.
Wonderful! Looks like the lens is a winner, at least in good hands!