Normal for RawDigger to have much higher value for blown highlights?

[l_d_allan]

With my 6d at ISO 100, RawDigger treats values of 13,236 and above as that channel being blown.

With Dual-ISO and 100/800, RawDigger treats values of 57,539 and above as blown.

Values in a "black trap" go as low as (0,0,0,0).

Is this "as expected"? My impression is "yes", but I wanted to check for sure.

[Audionut]

The DNG output from cr2hdr is 16bits.

[dyfid]

The DNG output from cr2hdr is 16bits.

So is the output from cr2hdr no longer raw then? Demosaiced and scaled to 16bit and not that the dual iso holds two exposures and therefore raw channel levels are higher? Like BMD raw channels are up in the 50,000 range.

Don't bother pointing me to a thread to explain as I'm starting to try dualiso and capable of own research.

[Audionut]

Don't bother pointing me to a thread to explain as I'm starting to try dualiso and capable of own research.

Start by understanding bitdepth.

http://www.cambridgeincolour.com/tutorials/bit-depth.htm
http://www.cambridgeincolour.com/tutorials/dynamic-range.htm

[Iliah Borg]

With my 6d at ISO 100, RawDigger treats values of 13,236 and above as that channel being blown.

With Dual-ISO and 100/800, RawDigger treats values of 57,539 and above as blown.

Values in a "black trap" go as low as (0,0,0,0).

Is this "as expected"? My impression is "yes", but I wanted to check for sure.

Dear Allan,
Have you looked at http://www.rawdigger.com/howtouse/rawdigger-histograms-overexposure-shapes ?
To determine the clipping point, you can shoot a curved shiny surface, like a bell, a spoon, a ball from a bearing (I happen to like DATACube, as it also contains a useful light trap for black point) and study the histogram of the rough selection around the specular highlight in RD.

[l_d_allan]

Have you looked at http://www.rawdigger.com/howtouse/rawdigger-histograms-overexposure-shapes ?
To determine the clipping point, you can shoot a curved shiny surface, like a bell, a spoon, a ball from a bearing (I happen to like DATACube, as it also contains a useful light trap for black point) and study the histogram of the rough selection around the specular highlight in RD.

I'll read the entire three series of articles, and expect to learn a lot. Thanks.

I used to have a Datacolor SpyderCube, and found it very useful. I did manage to misplace it, and came up with a do-it-yourself substitute with "black trap" and a stainless steel spoon for spectral highlights.
http://www.dpreview.com/forums/post/54142816