Why does C1 ignore ISO of my .dng files?

[lowep]

How can it be that two different images of the same subject in the same light taken within seconds of each other at different iso (ie 100, 200, 400 iso otherwise same MFDB settings) both look the same and present the same histogram in C1?

The files were downloaded and converted to .dng from Sinar eMotion75 MFDB with Sinar Captureshop.

When I open the .dng files in Captureshop or Photoshop they are fine (as I expect there is a considerable difference in the histogram due to the difference in iso).

Maybe the problem is that C1 does not support Sinar - though I thought this would not be an issue once the files were converted to .dng. Maybe not all .dngs are the same?

I thought there could be a bug in C1 5.2 until I tried the trial version of C1 Pro 6.2 that did not solve the problem.

Could this be because removing the old version then installing a newer version of C1 does not remove old C1 user data such as preview files stored on the computer by earlier versions. Hence the problem is caused by a bug in the old version but continues to rear its ugly head when I install the new version?

I posted this question elsewhere a while back but nobody replied so try again hoping somebody on this forum can shed some light on this weird phenomena that BTW I have tested and found out has nothing to do with excessive caffeine intake.

 

[lowep]

Here is the gist of the prompt reply I received from Phase One technical support after I wrote to them about this yesterday:

in regards to DNG files the format is only supported when shot with a camera and then imported directly into Capture One. Converted DNg files from other applications are not supported

 

[lowep]

So either forget about C1 or find a work around, right.

Would it be totally out of the ballpark to guess that one reason for the problem I am encountering is that iso is not an inherent characteristic of a raw .dng file but metadata that is wrapped with the file by the camera when the photo is taken then read and applied by whatever software program is used to process the raw .dng file?

This could explain why C1 can see the different iso data of the 2 files but does not have the right muscles in place to access and apply this information. If this were the case then maybe all I need to do is to use the C1 exposure slider to manually boost the exposure of the raw .dng +1 stop (difference between 100 and 200iso) to get the same result as if C1 automatically dialled in the difference in iso...

when I do this the resulting difference in the histogram looks quite similar to the difference in the histograms of the "same" image at 2 different iso's automatically produced by other raw processing programs

maybe I am barking up the wrong tree? :loco: