Hi Colin. I agree, I like Bryan's tests. They do give you a more real world flavor. But one of the things that Bryan does that is great is gives us the ISO 12233 charts with the same camera, usually the 1DIIIs or 60D, and then multiple cameras (every camera body can be compared with the EF 200 f/2.0). Generally it is not recommended to compare lenses based upon shots taken with different camera systems. It is a great tool to compare camera bodies based on the same lens.Originally Posted by Colin500
In discussing the resolving power of a lens vs a sensor and comparing a crop sensor and FF sensor there is a second factor to consider in addtion to pixel density when assessing Byran's charts, and that is distance from the subject. The combination of pixel density and the distance from the subject are what determine how many pixels are "on target" or how many pixels are used to define each inch of a subject. The way Bryan does his tests, the full 21 MP of the 1DIIIs and the 18 MP of the 60D are being used to define the subject, which is a more "real world" comparison. While the 60D has a higher pixel density, it is not 100 percent comparable because the 60D is actually using less pixels on target than the 1DIIIs.
That said, I do think that Busted/Mike is on to something. I don't think the difference seen in the comparison is exclusively due to the 3 MP difference in resolving power. I suspect there are some limitations in the resolution due to the lens. Which does indicate that there will be diminishing returns in higher MP due to the resolving power of even the best of lenses. I say diminishing returns because the counter to this point that I've read essentially amounts to even if you are better defining lens blur, it is still better definition. But, needless to say, it is diminishing returns on the higher and higher MP you have.
Somewhat on the same topic, I ran a poll a while ago asking the ideal number of MPs would be in a body. At least for those of us here at TDP, ~77 percent said 20-30 MP.
Reply With Quote