Our exclusive affiliate partner now has stock of the brand new Canon RF 15-35mm f/2.8L IS USM.
- RF-Mount Lens/Full-Frame Format
- Aperture Range: f/2.8 to f/22
- Three Aspherical Elements
- Two Ultra-Low Dispersion Elements
Canon RF 15-35mm f/2.8L IS USM at Adorama
They let you choose which camera to use in combination with the lens for the comparison, however, they don't necessarily have all camera and lens combinations in their archive. If they were to run through the tests with every single camera and every single lens for each release, it would take them an extraordinary amount of time.
In this case, the EF lens was actually never tested on the 5Div (which would be the same sensor and AA filter as the EOS R), so unfortunately they don't have a useful tool for comparison at the moment.
It's important to note, that The Digital Picture did not themselves indicate this was an appropriate comparison to make. KirkD simply selected these settings using their available comparison tool on the website, and came to a misleading conclusion.
But really you shouldn't be commenting on lens performance if you don't have even the faintest of clues about what you're looking at.
It doesn't quite work that way, and if you extrapolate out you'll quickly see why. In other words, would an image taken on a 10Mp sensor look the best? How about a 1Mp sensor?
The reality is that perceived sharpness is a combined result of sensor resolution (the higher the Mp count, the more individual data points to build the image from) and the resolving power of the lens (the more precisely the optics can focus light, the more distinct the reading from each photo-site on the sensor will be).
And in the case of these two cameras, there is also the issue of the Anti-Aliasing filter on the EOS R. AA filters very slightly blur an image in a way that is designed to reduce moire. The 5DsR has no AA filter (that's why is has the "R" in the name, for increased Resolution).
The disadvantages of higher Mp sensors (given the same sensor size) is in the additional noise that results from having a smaller photo-site per pixel, as well as a higher data rate to handle which can slow down shooting. But at low ISOs, such as in the test conditions used by TDP, the 5DsR simply has a superior sensor to the EOS R, and will produce much more detailed images.
Increased sensor resolution does not simply “magnify” the image. If the image consists of black on white lines, any further sensor resolution would definitely show increased detail.