a6k Loc: Detroit & Sanibel

This article by Mr. Borg, one of the experts behind RawDigger may help explain. Some key points IMO:
1. There is no ISO standard applicable to raw
2. It is common for camera makers to apply different standards to raw vs JPG "middle gray".
3. The result of the different standard is that the raw middle gray leaves more room from middle gray to fully saturated than JPG.

The PDF is downloadable. The two screenshots from FastRawViewer are from the same picture using "raw+jpg". The files were not edited at all. For those who don't know, FastRawViewer uses the same technology as RawDigger. The exposure was of my monitor's screen. The screen was displaying a background I created which is 255,255,255 or as white as possible. The camera, of course, tries to render it middle gray. You can see both in the part of the image that is showing and in the histogram, the significant difference. This merely demonstrates the understanding from the article.

Using FastRawViewer's ability to increase exposure in the display in 1/3 stop increments and its ability to show over exposure I demonstrated that the distance from the raw image's middle gray to maximum is 3.33 stop but the distance for the JPG is less, perhaps only 3.0 stops.

You can tell from the filenames which is which. Also by the caption on the histogram. BTW, using Mac's Preview does not show this. Like most viewers, it interprets a raw file according to the embedded JPG. But FastRawViewer does it right.

Downloadable PDF
Attached file:
(Download)

a6k Loc: Detroit & Sanibel

I should have added this mathematical tidbit:
12.5% is 3 stops and 18% is 2.47 stops.