how many MP do you really need?
 

I know that MP count comes up a lot, it seems that many casual shooters hold to the belief that more is better, but those who shoot more aren't so bothered by it. It seems that unless you are shooting for huge print sizes then a 6mp camera should hold up just fine. I have recently had some 20"x30" prints done of photos taken on 8mp and 10mp cameras and they all look great, even when viewed close up. There is also a lot of talk that higher mp cameras perform less well at high ISOs, so why have I just bought a 15mp 1.6x crop camera...?

My main camera is a 16mp full frame which I love and the second body is an 8mp cropper (a EOS 30D). Last week I was offered a used 50D at a reasonable price and as I had some cash in my camera fund I went for it. It arrived yesterday and has some improvements on the 30D from a usability point of view so it looks like a good choice. So I decided to take a test shot to try and see how much use the extra 7mp (almost double that of the 30D) is likely to be. Attached are unsharpened test shots from each camera, first is just resized and second is a 100% crop to show how much detail each has captured. Shots were taken at f8, 1/50th, ISO400 on a tripod through a 180 macro lens.

To my eyes the shot out of the 50D looks slightly sharper in the full version (though the slightly different exposures may have effected this impression), on the crops it is clear that the 50D is recording slightly more fine detail as would be expected. The advantage of the extra 7mp isn't huge, I reckon that a 8mp camera will do the job fine the vast majority of the time.

I couldn't really tell the difference between the first two pixel-peeping ay 500% with FastStone. Both camera pretty impressive - especially given the ISO400 setting. Any Chance of a comparrison at higher ISOs - 800 and 1600?

This was discussed in some detail here:
http://www.worldphotographyforum.com...ead.php?t=2495

'How many megapixels do you need?' always reminds me of my children: 'Dad, I need an icecream!' The point being that most of us most of the time dont need huge pixel counts for our usual outputs. 'Want' though is another matter ;)
I would love to upgrade to the 1DsIII, but I really dont need the extra resolution, even though the newer processing engine, better high ISO performance and built-in sensor cleaning would be nice. (I can always find excuses for more kit, if only the money were as easy!)

When I get the chance I'll do a three way comparison between the 30D, 40D and 50D at a range of ISOs... but it might have to wait until the school holidays are over!