Originally posted by Fogel70 But why must you get much better performance out of a larger sensor when comparing cameras?
Maybe because getting better performance is the goal of buying and using a larger sensor in the first place? If not, why would you want to buy one ?
Originally posted by Fogel70 Aperture f/2.8 do not magically get better than a slower lens. And the smaller the pixels are, the higher the requirement on the lens get, which most lens review show as Q lenses struggle to get the same resolution as lenses for larger sensors.
I can assure you that wide open, at its long end, the 06 lens fare much better than most consumer 5.6 zoom at their long end. I can tell you that my 06 on a Q7 can make a tough competion to my 55-300 on an APS-C. And I often prefer to go for the Q7+06 instead of the K500 + 55-300... I only use the 55-300 if I need the extra reach or better AF. In fact, this damned 06 makes me seriously think that I should upgrade the 55-300 for a 60-250 or 50-135... But that's another story...
Originally posted by Fogel70 Using a larger sensor you can get the same speed out of a slower lens as the larger sensor produce images with much lower noise so higher ISO can be used.
Say you get acceptable result from 1/500s f/2.8 ISO800 on Q. You would get just a good image from m43 at 1/500s f/5.6 ISO3200 or on APS-C with 1/500s f/8 ISO6400.
m43 has more than 4x the sensor size of Q, so you can expect 2 stops better noise performance on m43.
APS-C has more than 8x the sensor size of Q, so you can expect 3 stops better noise performance on APS-C.
Yes, but what's the point of getting a pricier, bigger, camera body to only get you to the same point of a smaller cheaper one only because you don't want to put a fast lens on it ? Sure, you can decide to use 5.6 lens on a m43 or a APS-C and crank up the ISO to compensate, but what's the point if in the end you don't get a significantly better IQ ? What is the point of getting a larger sensor body if only to tie it with lenses 2-3 stops slower ? What are you trying to demonstrate by showing that you could get results that are only as good as a small sensor with bigger ones ? I hope they do! It's the least they can do, but I expect them to be significantly better, not just the same.
And that's the point of comparing 2.8 lenses between these system. Because it's what will allow you to get a significantly better IQ with what is supposed to be the better sensor. If you only get "as good as" and want a compact system, you just take the smaller one... Because, it only make sense to get the larger one if you can get something better out of it, meaning using a lens that is at least as good.