Originally posted by clackers D1N0, if the correct exposure on FF for a scene is 1/125s, ISO 100, f2.8, guess what?
The correct exposure on APS-C or m4/3 is 1/125s, ISO 100, f2.8.
Noise is something else, related to pixel size and body design, not sensor size.
So you get the same exposure on FF and APSC or MF or m4/3 (or a compact) with 1/125s, iso 100, f/2.8. Yes
But there an infinite number of combination with different apperture iso, shutter speed that would do the same a few example
- f/1.4, 1/2000, iso 400
- f/5.6 1/125s, iso 400
- f/16, 30s, iso 50 + ND64
I expect that one doesn't choose theses values by random but for a reason.
This suddenly mean that all theses setting are important. Apperture is for deph of field control, shutter speed is for movement control... And sensitivity is totaly abstract number that affect the noise level.
So I would hope somebody to choose the apperture and shutter speed for good reason and let the iso adapt, couting the noise is not too high.
The effect of apperture on a scene depend a lot of the focus distance and sensor size. I would expect somebody to choose different appertures on m4/3 and MF for getting the same results.
Some details like the bigger sensor perform noticably better at high iso and that lenses tend to perform noticably better stopped down a bit and that bigger sensor can keep acceptable sharpness with lenses more stopped down means:
- For long exposure bigger sensor can get less light while keeping diffraction low and get longer exposure with same ND filter.
- For shallow deph of field bigger sensor can use smaller apperture and thus higher picture quality for same deph of field.
- When shooting in low light bigger sensor can keep lower noise level at the expense of deph of field or get the same deph of field and same noise.
Of course all of this come with the issue of having quite bigger camera/lenses, higher price and difficultlies to achieve wide deph of field in some extreme conditions.
For me APSC is a great compromize. FF could with small primes. m4/3 I never tried, but why not? For now I'am invested in Pentax APSC and I'am happy with it.