Sony A7R V: Strictly Avoid The Lossless Comp (M) and Lossless Comp (S) Formats
Related: Adobe, Adobe Camera Raw, baseline exposure, Expose Somewhat To Right, Expose To The Right, exposure, histogram, LibRaw, post processing, RawDigger, Sony, Sony A7R, Sony A7R II, Sony A7R III, Sony A7R IV, Sony A7R V, Sony mirrorless
re: post processing and Adobe Camera Raw
re: ETTR
ETTR = Expose To The Right: increasing exposure for RAW capture so as to minimize sensor noise, maximize dynamic range. The term refers to a histogram pushed right.
ESTR = Expose Somewhat To Right: increase exposure but don’t get greedy!
re: Color Shift when Using Optimal ETTR (Birch Trees in Winter)
ETTR Too Much of a Good Thing? HARD to Get it Right
“Baseline Exposure” Boost in RAW Converters can Whack Color
Evaluating ETTR, I was fooled by Sony’s Lossless Comp (M) format, having inadvertantly set the camera to that (not sure when how).
Not only do the Sony Lossless Comp (M) and (S) formats downsample from 60MP to lower-res, the overall behavior is radically different from full-res RAW files, flattening colors and squashing things in general well before overexposure. Or, the best way to turn your world-class camera/sensor into a 3rd-rate dumpster fire.
Terms and words matter: to call highly processed data "RAW" is ridiculous and misleading at best.
As pointed out by Alex Tutubalin of LibRaw:
Sony Small/Medium RAWs are not RAW but compressed YCC format.
Compression is lossless, while RAW to YCC conversion is definitely not (white balance applied, out-of range values clipped, etc). In addition, color channels are subsampled.
Generally, it is JPEG on steroids: no lossy DCT-based transform, higher bit range, but closer to JPEG, not RAW).
The good news
ETTR behavior with full-res 60MP Lossles Comp (or Uncompressed) is radically better, indeed spectacularly good.
But matrix metering is spectacularly bad.
Sony A7R V Metering Throws Away as Much as 2.33 Stops of Dynamic Range.
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