rhys216 wrote in post #13181181
I still think the 5D2 would be clearly sharper in terms on MTF figures even without a mega pixel advantage (the lens is clearly the limiting factor), as even with an extremely sharp lens at it's sharpest setting the 5Dii is producing 40ish% better MTF numbers with only a 15% mega pixel advantage.
Look, dpreview.com posts up 100% crops of the resolution test images they use to determine the resolution of the cameras. You can look at them yourself. They show you exactly what the potential of the camera is. They're not using some special, magic, unobtainable lens, they're using the Canon 50 f/1.4 on the 7D and, I think, the 85 f/1.8 on the 5D. Or, at least, that's what they used to use as I recall.
However, I'm not saying there will be as much of an appreciable difference between the two in the real world in such a case, as the image will be very sharp in both cases and probably difficult to tell the two apart, but it would make a noticeable difference if your shooting a lens or using an aperture that isn't extremely sharp.
And that's the point!! The claim has been that full frame gives you a very visible improvement in sharpness and detail retention, even after you eliminate the resolution difference. And for that, I call BS. Yes, you're right, if the glass you're using on the crop camera isn't up to the task then clearly the full frame camera will have an obvious advantage, and it'll be easy to see. I have never disputed that. The crop camera is going to be more demanding of the resolving power of the glass. I have always said this.
But if you put good glass on the crop camera, it will perform, and it'll do so in such a way that it'll be difficult to tell the resulting images apart. Ben Jacobsen illustrated this quite nicely in his 7D vs 5D2 landscape comparison thread here.
You people who claim there's such a major difference between the two and who claim that the only people who don't see it are people who don't have extensive experience with both are refusing to listen, plain and simple. People like Ben Jacobsen have the very experience you claim is necessary, and they say that there is precious little difference between the two. They've posted like versus like examples illustrating just how close the results really are.
Glass matters, a lot. There's no question about that. That's not the point. The point is that if you have good glass on your crop camera then you will get results that come surprisingly close to the results you'll get from full frame. The only major exceptions are depth of field and noise. For those, full frame unquestionably has the advantage. For high ISO, where you're willing to use the lens wide open, full frame also unquestionably has the advantage, but only if you're willing to open your lens up all the way. For everything else, the full frame advantage is minor. It's there, yes, but it's not substantial unless you're not using sharp glass on the crop side of the equation.
One more thing: you must keep in mind that the 7D has a green channel imbalance that most RAW processors deal with by averaging the green channels together. This results in loss of detail. If you're going to properly compare the potential of the camera, you have to use a RAW processor that does not do this. Lightroom is apparently one such RAW processor (and, by extension, ACR 6.x). The T2i, T3i, and 60D are, as far as I know, free from that defect (Daniel Browning would be able to answer that question more adequately), but I don't know if most RAW processors treat them any differently than they do the 7D.
