32bit HDRi .dng files have two parts - don't open in PS

[leolyons]

I am batch scanning 35mm BW negatives using Silverfast SE Plus 8.2. If I scan a strip of six negatives three or four of them will be saved as single .dng files and I can open them in Photoshop and invert them. The remaining frames will be saved as .dng files but will also have .dngnnnn files with them - the n's representing a four digit number eg 6096. These .dng files will not open in Photoshop giving the error message 'Could not complete your request because it is not the right sort of document'.

Any ideas? If I rescan the same frames immediately they often save fine with a single .dng file.

If I save them as .tif files instead will there be any disadvantage to the output?

[LSI_Ketelhohn]

Dear customer,

Is the target folder open during scanning?
If so please close it.
What you describe happens when Windows tries to build thumbnails from the images while SilverFast is still working on them.
But you can simply delete the number from the file ending and the file should be fine.
In case there are two files (one with and one without number) the one with the number is a temporary file which could not be deleted.

Kind regards,
Arne Ketelhohn.

[leolyons]

Dear Arne

Thank you for your reply and indeed you have identified the problem - I had the folder open in Adobe Bridge so that I could process the files in Photoshop whilst the next neg was being scanned.

One minor point with your reply in case others find it useful. The way to recover from the situation is to delete the file with only the dng extension. This will be the file that shows up as a thumbnail in explorer or Adobe Bridge etc. Once this has been done you can change the extension on the file with the dng plus number extension. Remove the number so that the extension is just dng. The file will then appear with a thumbnail and can be opened in a suitable editing program eg Photoshop.

I think one other thing that sometimes confuses people is that if you save a negative file as a dng it is a raw file and has had no form of processing applied therefore it will appear as a negative thumbnail. You can use the Invert command (Ctrl + i) to change it to a positive.

Regards

Leo

[LSI_Ketelhohn]

Dear Leo,

DNG (Digital Negative) files are supposed to contain unprocessed (raw) data.
That is their main purpose.
For processed data you will have to use a different format.

Kind regards,
Arne Ketelhohn.