On 8/30/2019 3:23 PM, Mike Gordon via olympus wrote:
<<<If one uses ACR (LR or PS), distortion correction is not optional.
Yes, no option using ACR to turn off use of metadata corrections. I haven't
reviewed this in a couple years. Some corrections in metadata also include CA
and vignetting. Starting 2014 or slightly before, Panny lenses on Panny bodies
began including the CA correction metadata. DXO does NR on the RAW data
pre-conversion, but that is fully user controlled. Not clear how clarity could
be applied pre-conversion though some other aspects of the image are baked into
the RAW files:
While this essay is a great resource, the title is a little misleading. Raw is indeed Raw, but useless until converted
into something else. The point is, I think, that the process is more interpretation than conversion. This is rather
obvious if one uses different converters on the same Raw file. I can see people wanting to know which conversion is the
CORRECT one, but the answer is both none, as there is no inherent converted result in the Raw file, and all.
The interesting thing that's happened since this essay is improvements in sensor systems such that some cameras may be
said to be ISO Invariant (over some range of ISOs). That is to say, the result of shooting at ISO 1600 is identical in
shadows/noise to shooting at ISO 200 and increasing luminosity by three stops in processing.
Quite remarkable is that this is true of some 1" sensor systems, such as the
Sony RX100 and Panny ZS200:
"The ZS200's sensor is essentially ISO invariant, so you can (in most instances) shoot at base ISO and increase the
brightness several stops while processing the Raw image, with a minimal noise penalty. By keeping the ISO low the camera
captures additional highlight data instead of 'throwing it away' at higher sensitivities by amplifying the signal. You
can see similar results from the Sony RX100 IV, which has a more modern CMOS sensor. In turn, this gives some scope for
underexposing a low ISO setting to protect highlights, then brightening later."
They don't mention it, but this also means it will generally be possible to
underexpose to maintain usable shutter speeds.
This change makes some of the conclusions of Ctein's tests rather moot, as one may choose exposure arbitrarily and
adjust "exposure point" and curve later, with no IQ penalty.
What if the Hokey Pokey *IS* what it's all about?
Themed Olympus Photo Exhibition: http://www.tope.nl/