Quote Originally Posted by Feanor
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?

At ISO 3200 vs. 800, the comparison will still favor the TC. Furthermore, the difference will be visible in midtones instead of just the deep shadows. This is one test that anyone with a TC can do.


Quote Originally Posted by Jon Ruyle
To reduce read noise, I think, you would have to use a *higher* iso, not a lower one. The problem would be blown highlights, not quantization.

Agreed.