Originally posted by rangercarp The argument is that the intermediate ISO's are not true ISO's but the processor simply manipulates the exposure to achieve the intermediate setting.
Yeah, I heard that before. I'm not sure if this still applies with modern cameras, or if anyone has done tests to prove/disprove it.
Originally posted by Sandy Hancock I'm too lazy to turn the dial three times as far to go from 200 to 400.
For me this was a bigger deal than possible IQ issues. At the ISOs that I usually shoot, the noise levels are so low it doesn't matter much if I bump EV by 1/3 in post, or even if its done in-camera.
I think this would only show up if you shoot at relatively high ISO and apply a good amount of PP (added contrast, EV, without applying special NR). I think this is the answer for OP. Do whichever is more convenient for you, unless you shoot ISO 1600+ and need to do a lot of PP.
---------- Post added 24th May 2016 at 18:43 ----------
Originally posted by robthebloke I use 1/3 stops on the k-1. To my eyes there is a difference between ISO 3200/4000/5000/6400/8000.
Yeah, but the question is whether shooting ISO 3200 and adding 1/3 EV in Lightroom or Faststone would bring out less noise than selecting ISO 4000 in-camera to begin with (shutter speed and aperture being equal).