Cropping a 64bit HDRi file

[michaelwe]

On scan, I cropped my 64-bit HDRi files a bit big, with many slight black borders, because the auto frame wasn't working well (dark images, auto frames cropped too small).

I will leave these files as my raw source files, but before I do that I would like to add metadata and crop the files without affecting the infrared dust detail.

PhotoMechanic can add metadata without stripping any of the infrared dust and dirt information.

But, my main question is: how can I crop these images and keep them in the 64-bit HDRi format? I noticed that Photoshop, PhotoMechanic, and Graphic Converter all lose the infrared data, even if you same them as TIFF after the crop.

SilverFast HDR can make a crop when you process a file, but you can't process a file back to 64-bit HDRi format, so you have to apply dust removal at that stage (and therefore cannot apply it again or differently in future) and end up, at best, with a 48-bit file.

Is there a way to crop a 64-bit HDRi file without losing any information?

[LSI_Morales]

Dear michaelwe,

The idea behind the HDR and HDRi files is to create a raw file which will be used as a starting point to create or edit your images but the file itself should not be changed because it comes with a quality loss implicitly.

If you want to spend time adjusting the frame during the postproduction, wouldn't it be better to spend that time before creating the file during the prescan stage so it has an even better quality?

Cheers

[michaelwe]

If you want to spend time adjusting the frame during the postproduction, wouldn't it be better to spend that time before creating the file during the prescan stage so it has an even better quality?

Elsewhere in this forum it has been noted that zooming into every prescan of, say, eight slides, to arrange and set the frame, is time consuming. It was suggested that a user make a bigger frame and crop after the scan.

Many of my originals are dark (mostly depicting museum gallery installations with high-key spotlit subjects) and the frame is hard to determine on a small 'prescan' scale.

For me, cropping the 'raw' file would be OK, no violation of the sanctity of the 'master' version I intend to archive. Likewise, I would also like to be able to add metadata to the raw file (which I can, thankfully, with PhotoMechanic).

With the workflow you are suggesting, I need to reframe the image now every time I make a derivative version. I regard that as a time-wasting nuisance, and something which could be accidentally omitted or incompetently done. SilverFast's batch processing of raw HDRi files to JPEGs, with dust reduction, is good enough that for many images it is all I need.

Also, with the workflow you are suggesting, if I want to avoid re-cropping the image each time I make a derivative, I need to keep the original raw TIFF as well as a high-bit cropped TIFF with dust information stripped out. In both cases we are talking of file sizes of 20 – 50 MB, consuming unnecessary (to my opinion) storage.

[LSI_Morales]

Dear michaelwe,

Elsewhere in this forum it has been noted that zooming into every prescan of, say, eight slides, to arrange and set the frame, is time consuming. It was suggested that a user make a bigger frame and crop after the scan.

You are right, zooming into every picture of the holder is indeed time consuming. At this time SilverFast HDR does not have the possibility to crop and save into 64 bit HDRi format.

One possibility would be to make the necessary dust and scratch correction as well as the reframing and crop in SilverFast HDR then save the file into 48 bit HDR. Which makes for a corrected raw file without the infrared channel. (you won't need the ir. channel after all, if your picture has been corrected. will you?)

Cheers

[michaelwe]

Thank you, and that is possibly what I will choose to do. Of course, if I then delete the 64-bit HDRi file to save space, that does not allow me to reprocess for dust/scratches if either SilverFast HDR as a program, or myself as an operator of the program, get better at removing dust/scratches in future. If HDR could save back to HDRi format, I would not have to make that choice now.

[LSI_Morales]

Dear Michaelelwe,

Right, as I explained, SilverFast HDR does not have that possibility. I will create a feature request for future consideration.

Thanks for your cooperation.

Cheers

[michaelwe]

Thank you.