from Ai to HDR; Negafix not matched?

[Gregory C]

hi.

I tried this. it didn't work.

SF Ai Studio ME (Nikon);
scanned negatives using ME and non-ME in Positive scan mode.
output scans as both 48-bit Color and 48-bit HDR saved in JPEG2000 lossless.

SF HDR Studio;
in Negative scan mode.
opened the JPEG2000 files.

if I select the same Negafix profile in Ai and HDR, the results are very different. images opened and converted in HDR are greener than images converted directly via Negafix in Ai Studio.

have I missed something? shouldn't HDR be able to equally use Negafix to convert images scanned in via SF Ai ?

regards,
Gregory

[LSI_Muenier]

Dear Gregory,

please scan your film strip in negative (!) HDR mode.
This activates a special color match, so that you will get the same results when working in HDR/HDRStudio as directly in NikonMaid.

Best regards
Martin

[medikoo]

Other thing worth to mention is that in Ai all correction calculations are based on preview scan not full resolution scan (as in HDR) this also leads to different results - what's worse sometimes better results are from preview scans in AI :/

You should have nearly exact results between Ai and HDR Studio when you setup highest possible resolution for preview scans in Ai.

It would be nice if it would be somehow possible to emulate preview scan results from Ai in HDR

[LSI_Muenier]

Dear medikoo,

if you have your scan frame visible in Ai and HDR by the same (pixel) size,
then both applications will act almost identically.

Best regards,
Martin

[medikoo]

What I was referring to is not effect of different frame size.
I'll put it in example:
I make 48bit HDR full frame scan and open it in HDR Studio and I prescan again same film frame in Ai Studio for full scan (exactly same frame size - as for HDR scan).
In Ai Studio when I work on "High resolution prescan" set to "x1" I get sometimes very different effects than in HDR studio.. but the higher prescan resolution I set in settings the results are closer to what I have in HDR Studio. So yes.. if I work on "High resolution prescan" set to "x8".. results are identical as in HDR Studio.. however on "x1" setting they are different (I noticed that on ISO 800 negative.. I didn't spot noticeable difference when scanning positives).
I believe that it's the cause of different amount of information that silverfast got in both cases. HDR makes corrections on full frame scans while Ai on what it got from preview scan - and it may make difference. Do I got it right?

[LSI_Muenier]

Dear medikoo,

what kinds of difference do you observe?

Best regards
Martin