APS-C vs Full frame – Conclusion
As this investigation has shown, new developments in sensor technology mean that the APS-C-format EOS 7D is capable of resolving almost as much detail as the full-frame EOS 5D Mark II and the results have a similar level of noise.
However, the D3S and D300S demonstrate the positive impact that larger photosites can have upon the level of noise in image. Meanwhile, the Sony Alpha 850 and Alpha 550 show how increasing the pixel count of a camera allows it to capture more detail.
When Canon eventually replaces the EOS 5D Mark II, it is reasonable to expect the new camera to have technology that is at least on a par with, if not ahead of, that found in the EOS 7D, and the pixel count could go up. This is purely speculation, but it would mean that the full-frame camera could jump ahead of the EOS 7D.
While manufacturers now offer very short focal length lenses to counter the negative aspects of the focal-length magnification factor experienced with APS-C-format cameras, the optics specifically designed for the smaller format don’t tend to have as large a maximum aperture as their full-frame counterparts. This isn’t a problem for photographers concerned with capturing images with extensive depth of field, but those who like to shoot with limited depth of field may struggle to achieve the degree of blur they want.
On the plus side, wildlife and sports photographers are able to frame their subjects more closely with smaller, less costly lenses when they shoot with an APS-C-format camera than when they use a full-frame camera.
Differences in size and weight have in the past been a deciding factor for photographers choosing between a full-frame and an APS-C-format camera, but the EOS 7D and EOS 5D Mark II indicate this may not always be the case.
Given that the EOS 7D and EOS 5D Mark II are both capable of producing images that make good A2 prints, perhaps we have reached the point where photographers can choose between full-frame and APS-C-format cameras on the basis of the type of photography they prefer, rather than because of significant differences in the quality of the images they produce.
