Over at SONYALPHARUMORS Andrea published a link that compared the new Zeiss Otus 85mm f/1.4 on a Sony A7r to the first generation Sony RX100 and came to this conclusion.
'So there you have it. Incredible resolution from the Otus, but that didn’t surprise me. Pretty damn good show by the RX100, but that didn’t surprise me either. What I find astonishing is how little difference there is between the two, considering the vast difference in size, weight, sensors and price. Sure, the A7R/Otus combination wins, but not by that much.'
Hmmm, I thought.
But then I realised that I've got an A7r, I've got the Sigma 50mm f/1.4 ART lens and I've got the Sony 1'' sensor (latest version) in my RX10, so why not have a look, see how they compare and decide for myself.
So I set up a test with both cameras tripod mounted at a variety of ISO settings. I selected apertures on each lens to even up the DOF a bit. f/4 on the RX10, and around f/8 on the Sigma / A7r combination, though with the adapter that's pretty much guesswork.
Here is what I got.
Now I'm a fan of the RX10, it's a great camera and that 1" sensor lets me do all kinds of wonderful things. But the results aren't even close. Now I've never tried a Zeiss Otus 85mm f/1.4 but I can't believe that it's worse than the Sigma 50mm in terms of image quality, in fact it's supposed to be the best lens ever made or something like that.
Now I've written lot's of posts about how different sensor sizes aren't that much different. I've also written the same about lenses. But this is one of the most extreme tests that I'm able to do and that was the thrust of the article I've linked to above. Now I'm not going to make any further comment on that because we all have to decide what's important to us, aside from saying that I know which I prefer.
And I also know just what I think of the difference between the two and how important that is to me. Now that doesn't mean I won't use the RX10, because in many situations it's the right camera for me. But I'm certainly not going to ascribe it magic powers that it doesn't have and I'm also not going to talk it up when it's clear that there is a significant difference.
For the speed, convenience and silence of the RX10 there are times when I'm prepared to compromise somewhat on image quality, because that's what it is, a compromise. But I have no need or desire to pretend otherwise and I find it strange that others may feel differently. Because ultimately what's the point?