06-14-2016, 08:06 PM
Quote:Film speed and sensor speed are not the same - but there's a standard for them: https://en.wikipedia.org/wiki/Film_speed see The ISO 12232:2006 standard and Measurements and calculations.So we agree that the old film idea about speed is not valid, as we do not have sensors of same sensitivity very often, and we can set ISO settings to whatever we want. So. "speed" with digital is not what it used to be.
Btw., sensor area doesn't play a role in the formulas, if I'm not mistaken.
Now, instead of talking theoretically I wanted to see if I'm wrong. I set up the same ISO, measuring method and aperture. First was 23/1.4 (APS-C) and 35/1.4 (FF)
Both 1/200 as shutter speed - where is the equivalence? Should be 1/200 Ã— 1.5 = 1/133
Next with f/8: â…›" on both cameras
Next were 35/2 (APS-C) and 50/1.4 (FF), I don't have a 52.5 mm lens
1/40 for APS-C Ã— 1.5 = 1/26â…“ for FF - but FF shows 1/50. Equivalence?
You can remain in your thinking model and I will in mine. I just never saw a proof for your reasoning. Maybe with a better lit test scene than mine.
You took care of setting an equivalent focal length. You took care of setting an equivalent f-stop. You forgot to set an equivalent ISO setting. Why?