Export to HEIC/lossless

I am currently digitizing my 10,000 negatives from several decades of film photography.
To use my conversions outside Lightroom I export to TIFF.
Typical file size is well over 100MB.
When I export these TIFF files to HEIC/lossless (Using macOS Preview ) I get 15 MB files.
What gives? Is there any negative aspect to this approach? (pun not intended)
Would it make sense to have NLP provide this export feature?
Thanks!
Ami


!

Hi,

I see that your HEIC file is being export at 8 bits/channel. Your TIFF file is likely at 16 bits/channel. Which probably accounts for at least some of the difference you are seeing in file size.

-Nate

Thanks for your response. It is indeed 8 bits/channel depth, because MacOS does not support 16 bit (it’s grayed-out in the converter). I couldn’t find a decent converter to 16 bit heic.

Still, any thoughts on this format as alternative to tif?

One issue is that you would be locking yourself into a proprietary file format (which would make Apple happy!).

More generally, using a lossy file format (whether HEIC or JPG) clearly saves significant storage space. Lossy formats usually allow the degree of compression to be chosen, and of course they’re designed to minimize the visibility of any compression (i.e., you may be unable to see any difference between a TIF and a compressed format except perhaps at the 100% pixel-peeping level). The biggest downside of compressed formats would be if you repeatedly reprocess and resave them, which would lead to progressive image quality loss. But that can be prevented by properly setting up your workflow.

Thanks for responding. Two comments:

  1. HEIC is not proprietary. From Wikipedia: it was developed by the Moving Picture Experts Group [MPEG]… was adopted by Apple in 2017 with the introduction of iOS 11, and support on other platforms is growing.
  2. HEIC allows for different compression rates. At the extreme (see my image I attached) it is lossless.
    ~Ami

HEIC is subject to licensing requirements: Could someone expand on this? What are HEVC, AVIF, and HEIC licensing and why a... | Hacker News

So although in the strictest sense it may not be proprietary, it’s certainly not open source or license-free. This is probably why you couldn’t find a decent converter to 16 bit heic.

I would use compressed TIf. When exporting from Light Room Classic set your Compression to ZIP. It’s lossless compression and will be supported for a long while to come. I’ve saved 300 mb images down to 100 - 80 mb.