DNG Compression in Lightroom

I’m new to mirrorless camera scanning and I’m having trouble with file sizes.

I’m using a Fuji X-T3, and the infamous Fuji “wormy” effect was the first real issue I had. Really bad at only 50% magnification.
After trying Irridient, the clear winner is Lightroom’s ‘Enhance Details’. Though it’s extremely slow it yields the sharpest detail with absolutely none of the worms (which film grain seems to really accentuate). Iridient seemed to create it own version of the same worm pattern without the same level of detail. The only problem is a slight grid pattern effect at extreme magnification, something I don’t think would be noticeable in any real world situation like a print.
I’ve got a lot of negatives, and while I know another external drive isn’t a huge investment, the DNG files that result from Enhance Details are huge. A Fuji Raw is about 30-40 MB while the DNGs average around 140 MB! These are just 35mm scans, btw.

Has anyone found a better demosaicing option, or is there a lossless way to compress the lightroom-created DNGs? They can be a huge drag on my computer if I’m editing a whole roll at a time.

As a bonus I would love a “positive” version. I used to reverse the negative and then export as a TIFF for more detailed editing, but I now understand there are limitations to editing with a TIFF file versus a Raw or DNG…


DNGs created by Lightroom are already losslessly compressed. The only way to save additional space is to export them as DNGs with lossy compression enabled, and then re-import those smaller DNGs.

If Develop performance is your priority, not space savings, try editing with smart previews. See below.


Edit Smart Previews instead of Originals to improve performance

Introduced in Lightroom CC 2015.7/Lightroom 6.7

To increase Lightroom’s performance while editing your photos in the Develop module, Lightroom Classic provides you a preference option to edit Smart Previews of your photos even when Originals are available. Although this may display a decreased quality of your photo while editing, however, the final output remains full size/quality.

To set this preference:

  1. Choose Edit > Preferences .

  2. In the Preferences dialog, select the Performance tab.

  3. In the Develop section, select Use Smart Previews Instead Of Originals For Image Editing.

  4. Click OK and then restart Lightroom Classic.