2nd lens vs 2nd camera

If I bought a 2nd camera, say Sony A7R 36MP, which has 15 megapixels more than my old camera, the Canon 5D Mark II 21 MP, would the 15M additional pixels make up for the loss in resolution caused by enlarging a RAW file that was shot with a 24mm lens to the size equivalent to a 35mm lens file?

The Sony A7 is the first mirrorless FF sensor. There is no frame difference for both the A7 and the 5DmkII. 21MP is still plenty for most occasions...certainly start collecting lenses. The initial reviews I've seen of the A7 is that it's convenient for a small FF camera, but it's somewhat limited compared to DSLRs in some functions, lack of variety of native lenses.

Do you mean "can I effectively crop to the equivalent of a longer lens because of the higher res?"

nellyle wrote in post #16999321
Do you mean "can I effectively crop to the equivalent of a longer lens because of the higher res?"

yes, which gives better sharpness...
1. cropping a file shot with a 24mm lens down to the size of a 35mm lens-equivalent file, using a 36MP camera, or
2. shooting with a 35mm lens with a 21 MP camera, no cropping

texshooter wrote in post #16999338
yes, which gives better sharpness...
1. cropping a file shot with a 24mm lens down to the size of a 35mm lens-equivalent file, using a 36MP camera, or
2. shooting with a 35mm lens with a 21 MP camera, no cropping

There's a lot more to shooting with different FL lenses than just the FOV, what you're describing is not the same thing.

texshooter wrote in post #16999338
yes, which gives better sharpness...
1. cropping a file shot with a 24mm lens down to the size of a 35mm lens-equivalent file, using a 36MP camera, or
2. shooting with a 35mm lens with a 21 MP camera, no cropping

option 2 would be considerably better.

Use option 1 when you're in a pinch and dont have the correct lens, it wont match.

21mp is pushing the limit of what most lenses can resolve. 36mp can help get every bit of the sharpness, but by no means is that amount linear.

Watch Tony Northrup's video first where he talks about and shows image samples of FF VS Crop sensors - http://blog.planet5d.c​om …their-lenses/?hvid=1LVxFW