Re: Would you recommend the M10?
nnowak wrote:
jwilliams wrote:
nnowak wrote:
The difference between m4/3 and APS-C isn't as great as the difference between APS-C and full frame.
APSC is 1.5x crop of FF. 1.5 squared is 2.25 so a FF sensor has 2.25 times the area of a APS-C sensor. m43 is 2x crop so a FF sensor is 4 times the area of a m43 sensor. 4 divided by 2.25 is 1.78 so APSC sensor area is 1.78 times a m43 sensor area. So you are right, but in either case it is roughly a stop difference from one format to another. A little more between APSC and FF, but not hugely different than APSC and m43.
Technically, Canon APS-C is 1.6X crop
Forgot this was the a Canon thread! I was using APSC crop everybody else uses.
The way I like to think of the different formats is in stops. Although this is an approximation it is very close to the actual numbers.
Yes, it is a close approximation, but the rounding skews in favor of APS-C. Here are the exact numbers...
FF base case
Nikon DX = 1.23 stops
APSC 1 Stop difference from FF
Canon APS-C = 1.39 stops
m43 2 Stop difference from FF
m4/3 = 1.94 stops
1" sesnor 3 stops difference from FF
Sony 1" = 2.9 stops
If comparing aperatures from different formats the above is real close to the actual differences in equivalent aperture. Also realize that if using the same image sensor technology, each format size larger will yield performance one stop better with regard to noise etc. So FF at ISO 800 is the same as ISO 400 on APSC is the same as ISO 200 on m43 is the same as ISO 100 on 1".
In a practical sense what this means is that a f2.8 lens on m43 is identical to a lens with twice the focal length and an aperture of f5.6 on FF.
Now someone is going to scream that the m43 is lens is actually an f2.8 lens and not a f5.6 lens! In case of exposure that is certainly true if ignoring the sensor behind the lens, but you can use ISO 400 with f5.6 on FF and get the same exact results as ISO 100 and f2.8 on the m43 assuming equal sensor tech in each sensor. You are using two stops smaller aperture on the FF, but the image sensor has 4x the imaging area so the same amount of light falls on the sensor either way.
Exactly, I wish more people fully understood equivalence. Compared to the M10 + 15-45mm lens, the new little G9x ties it at the wide end and is only down one stop at the tele end. The G7x and G5x beat it across the board.
Here's the fun one... my smart phone works out to a full frame equivalent of 31mm f14. That is less than one stop away from a Nikon 1 camera with the kit lens.
Thanks for taking the time to do the math more exactly. I knew it wasn't exactly one stop for each format size, but for deciding on using one format vs another it is a good easy to remember frame of reference.