Some very interesting points, thanks .


Quote Originally Posted by Daniel Browning


Quote Originally Posted by Feanor
Back in the days of the 30D when you were looking at 8MP sensors then pixelation would probably have been an issue before light degredation. But on a 21MP FF camera like the 5D2 I strongly suspect it's either roughly 50-50 or the other way round, possibly by a significant margin.

But the 8MP on 30D is *exactly* the same as 21MP on the 5D2. If the lens is good enough to use TC on the 30D, then it is good enough to use TC on the 5D2.
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I must have started writing my reply when you posted your original reply, I only just noticed it, sorry. I don't understand though what you mean by the 8MP on hte 30D being the same as the 21MP on the 5D2? 8MP x 1.6 gives 12.8MP, so the 5DII has another 1.6 times the pixel density as the 30D by my rough calculations. Surely that means you can make a 1.6x crop from the 5D2 twice over and still get the same resolution as the 30D? (one of the crops taking you from FF to APS-C equivalent)


And I see your point about ISO100 vs ISO400, but what about ISO800 vs ISO3200 for example? Surely at that threshold the read noise increase will be greater?