Hey All -


I've read a number of conflicting opinions / theories about using in-between ISOs, the 320, 500, etc. - and I'm hoping someone here is able to share "just the facts ma'am." (!)


I'm curious if those 1/3 increment ISOs are good to use, or should be avoided. In various photo mags I see ISO 500 or 320 etc. but more often I see 100, 200, 800, etc.


Is it true that camera CPUs arrive at those 1/3 ISOs by interpolation? That would mean they're not "native" to the capture system, but does that make them (by definition) inferior?


I've used my 40D at various ISOs and don't see anything unexpected at the 1/3 ISOs...


I'd like to learn the "best practice" ways to shoot - is avoiding in-between ISOs part of it?


Thank you for any thoughts you can share.