Revesre DNG image

[zagorchinov]

Dear SilverFast developers,

Currently, a scan from a negative film produces a negative DNG. This is understandable, since theoretically a DNG contains raw data and thus it is the raw representation of the negative film.

Unfortunately, besides its theoretical accuracy, this workflow doesn't provide any simplicity in the post editing workflow. The DNG format doesn't describe negative or positive data - all data is always positive. The result is that the programs used for DNG editing can't reverse the negative image. (For example Lightroom lacks this option, since it assumes DNGs as positive photos) The work around is to reverse the curves, but then all the image controls are also reversed. This means a darkening brush actually lightens the image. The editing of a DNG scanned with SilverFast becomes complicated.

It could have been much simpler if you provide an option for a reversed DNG file during the scan. It will actually conform to the DNG standard.

Keep up the good work,
Best,
Zagorchinov

[LSI_Ketelhohn]

Dear Zagorchinov,

unfortunately allowing modified DNGs would compromise our Archive Suite workflow.
So currently it is not planned to change this.

Kind regards,
Arne

[mjh1709muc]

I also support this request. I don't see a problem with the workflow there. Just set a exif/iptc tag (i.e Exif.Image.DNGPrivateData) that indicates if it is pos or neg so that silverfast HDR can handle it appropriate. I would even go one step further and would like to have a hdr dng with isrd already done on it.

[LSI_Ketelhohn]

Dear user,

The issue is that the DNGs should not be modified and converting them would be a change to the image content.
I am sorry but we can not change this at the moment.

Kind regards,
Arne.