5D MarkII VS 50D

[raff]

I have a Canon EOS 20D. Now I wish to change it.
My doubt is this:
I like the tele-lenses more than the wide. I like the possibility with my 20D to have a 480mm. using the 300mm.
Now: the new 50D has the same sensor dimension of the 20D, and it could be good for me.

My doubt is about the quality of the image that I can obtain with the 50D compared with the 5DMII.

If I shot a photo with the same lens (for example 300mm.) with the 50D and with the 5DMII, and I crop the shot made with the 5DMII to obtain the same ratio (1.6 enlargement) of the 50D, is the 5DMII sensor better than the 50D to have the same or a better image?

The 5DMII has a more extension of ISO, and more functions.
The video is not essential for me, but it could be usefull in some cases.

What's your opinion about my doubt?
Thanks for your help.
Ciao
Raff

[KeithB]

Well, a 1.6x sensor does not change your 300 mm lens into a 480 lens, it just changes the field of view.  If you just crop to the center of the FF frame, you can get the same effect.

If money is not an issue, I think that FF would be better, you leave your options open as to whether to crop or not.  I haven't done the math, but you might actually get higher pixel resolution with a cropped 5DMkII than with the 1.6x sensor - that would be the telling number.

[Bob Atkins]

The 50D gives you higher resolution than the 5D MkII. The pixel density of the 50D is such that you'd need a full frame sensor with 38.4MP to equal it.

So if you intend to crop your full frame inages down to the same size as would be recorded by an APS-C sensor, the 50D will outresolve the 5D MkII, assuming that sensor resolution is limiting (i.e. you have a good lens).

I discuss this in more detail for the 5D vs 20D case in this article: http://www.bobatkins.com/photography/digital/full_frame_vs_aps-c.html

I also discuss the sensor size issue in detail at http://www.bobatkins.com/photography/digital/size_matters.html

[raff]

Thanks Keith and Bob for you replies.
Bob, I readed your articles, I have only a doubt too...
About the QUALITY of the sensors in the 5DMII and in the 50D.
There are the same "serie" of sensors? Or the sensor of the 5DMII is new and better?
My doubt is (for example) about the high ISO extension. I've seen some photos made with the 50D in high ISO, and the results are... not so good: full of grain and pixel-errors. ( http://www.imaging-resource.com/PRODS/E50D/FULLRES/E50DFARI06400.HTM )
And this is a 6400 ISO shot, not a 12800 ISO!

Do You have tested the 5DMII and the 50D? Or, do You will test them?

Thanks again
Raff

[Bob Atkins]

I'm testing a 50D right now. At this point the 5D MkII is unavailable to mere mortals like me!

The 5D MkII, based on industry reports and advanced testing of pre-production models, appears to have the best high ISO performance of any Canon DSLR. This is to be expected since it is the most recent model and the pixels are larger than those in the 50D. Larger pixels, all else being equal, give lower high ISO noise.