> On Jan 26, 2017, at 10:19 AM, Mark Roberts <[email protected]> wrote: > > In the early days of digital it was standard practice to apply some > amplification to the signal from the sensor prior to analog-to-digital > conversion. This was how one increased the ISO setting. It's still > used in some sensors today but other sensors change ISO setting > strictly through software. These are said to be "ISO Invariant". (Most > Sony sensors are ISO Invariant and all the ones used in recent Pentax > cameras. > > What this means is that if you set the camera to, say, ISO 800 and > have a scene that meters at 1/100 sec. at f/5.6 you can, using manual > exposure, turn the ISO setting down to ISO 100 while keeping the > shutter speed and aperture at 1/100 f/5.6 even though the meter will > tell you you're 3 stops underexposed. If you just compensate later in > Lightroom or Photoshop the results will be the same as you'd have if > you'd shot at ISO 800 in camera. (This assumes one is shooting raw > format, of course.)
Thanks, Mark. That helps. It also raises something else I’ve been wondering about. Can I set ISO to a low value, use whatever aperture and shutting settings I want for depth of field and capturing motion, not bother about underexposure, adjust exposure in post processing, and retain the advantages of low ISO, i.e, a less grainy/noisy image? ------------------------------------------------------------------------------------------ Eric Weir Decatur, GA USA [email protected] (I)t is important that awake people be awake... the darkness around us is deep. - William Stafford -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
