SX50HS nature photography ebook

Steen Bay wrote:

It's easy enough to check. If the SX50 sensor can 'handle' a higher exposure (a longer/slower shutterspeed) at ISO 80 than at ISO 100 without clipping, then ISO 80 is actually a lower ISO than ISO 100. But even if the lower ISO can't handle a higher exposure (more light/photons), then that doesn't mean that the lower ISO is inferiour. Take for example the old 5D. ISO 50 on the 5D is actually the same as ISO 100. The two ISOs can both handle the same amount of light/exposure, and are therefore equally good. It's just that different tone curves are used for the two ISOs, with a different amount of highlight headroom above metered middle gray.

Anyway, my guess is that the SX50 has the same 12mp Sony BSI-CMOS sensor as the pentax Q (or maybe a slightly improved version), and according to DxOmark.com the 'measured' base ISO of the Pentax Q is ISO 92. Hope (and expect) that we'll see a DxO test of the SX50 before long.