Keeping RAW 48bit HDR Files Unchanged

[nicolasb]

Although SilverFast software has made it pretty straightforward to scan a film negative and produce a RAW file using 48 bit HDR settings in Ai Studio, it is less clear how to proceed with that RAW file from that point on. I am using SilverFast HDR Studio (6.6.1r2) to process my RAW scans from Ai Studio and wish to keep them as RAW as possible for later processing in PhotoShop RAW (basically LightRoom). Everything I have been finding about SF HDR Studio (including Ian Lyons’ “Digitize Your Analogue Images”) assumes that I want to do numerous adjustments in HDR Studio before I process for PS. I just want to convert my scanner RAW HDR neg images to positives, apply some resizing, apply some slight auto histogram adjustments (with no CCR or color adjustments) to make sure the shadow and highlight information is not lost and save as a tiff as close to my original RAW file as possible.

The processing stages (modifications and loss to my original RAW file?) start as soon as I drag my files from VTL to the JobManager window and must choose “keep original resolution” “process as neg” and “adjust images automatically”. After I set my parameters for auto under General/Options and exit I must choose again to save changes which appears to change the histogram either way. If I don’t click the lens icon button for auto adjust, the same icon remains on my Job Manager file and I guess the processing happens later? If I don’t do the auto adjustments, a curve icon (w/ red dot) appears in the JM file and adjusts later? Even when I select “48 Bit HDR in the Frame window and the control buttons dim, my image still appears to change.

How can I convert my RAW 48bit HDR scans to positives, do minimum highlight and shadow tweaking and convert to tif with the LEAST possible change (and loss) to the file information? All the information I find on this topic either doesn’t address keeping your files as RAW or show outdated versions of SF with controls and choices that do not appear when I am trying to use them.

Thank You, Nicolas B

[LSI_Morales]

Dear nicolasb,

When you create a RAW file with SilverFast Ai you actually create unmodified files. That file will actually be used as starting point during the post-process for further editing and manipulation but the idea is that the file will remain unmodified.

This means that you will open the file in HDR Studio, apply changes as in your case:

convert my RAW 48bit HDR scans to positives, do minimum highlight and shadow tweaking and convert to tif

During this step you will apply a gamma curve and invert every file as well as find and eliminate the orange mask of the negative film.
All that will change the file. This changes will be reflected in the end file which you will export by pressing the "Process" button.

At this point what you will do is to save this as a separate file which will be the one file used for further edition while leaving the original RAW file untouched.

Cheers

[nicolasb]

Alejandro,
Thanks for your reply. I understand that the original scanned file is not changed when using 48 bit files in HDR Studio, but since the file is not usable in Photoshop I need to process (reverse) it. What I was trying to ask was: how can I do the minimum changes (data loss) to the processed file coming from HDR Studio? It seems to me that changes are taking place when I drag files to Job Manager, when I select Frame options, when I set General Options, when I select Auto Options and finally when I "Process". Am I wrong about all these changes, is it just the screen image updating? I want to do the least amount of changing to the original scan, but still convert the file to a positive TIFF.
Thanks, NicolasB

[LSI_Morales]

Dear Nicolasb,

I understand that the original scanned file is not changed when using 48 bit files in HDR Studio, but since the file is not usable in Photoshop I need to process (reverse) it.

Of course you can use the file in photoshop, the advantage of doing it in SilverFast are the NegaFix profiles.

It seems to me that changes are taking place when I drag files to Job Manager

No, simply dragging the files to the JobManager does not have any effects, it does not apply any change to the image. On the other hand the options and corrections assumed within the JobManager are changes to the image which will be applied when processing the entire job.

...when I select Frame options, when I set General Options, when I select Auto Options and finally when I "Process". Am I wrong about all these changes, is it just the screen image updating? I want to do the least amount of changing to the original scan, but still convert the file to a positive TIFF.

The changes you see are just screen updates, the changes you have applied are all actually made only after you press the "Process" button, but essentially any correction you make to the file is a change that will be applied in the end.