Editing LR Classic image in PS CC creates huge image file

[wayneh92496952]

I have a brand new iMac Pro. Newly installed LR Classic. New Catalogue. Just downloaded a new PS application, all because of multiple problems with LR.

My issue is that before having installed all this new system I had problems with editing a LR image (whether an iPhone 8 HEIC image, a LR camera DNG image, etc) in PS the image size was huge in PS. For example, in LR Classic the image would be about 1 MB. But when opened in PS (either as a copy, the original or with LR edits) the PS image would be a TIFF file and was 69 MB. Once edited in PS and saved it would return to LR as a huge 69 MB file.

I worked with Adobe Tech Support including sending them my LR image and testing it on their end. They said it opened in PS as the same size as in LR. That is, about a MB. I was told to uninstall LR, sign out of LR, re install LR, etc.

Not only did I do that but as I mentioned I also had a new Mac OS X system and computer.

But I am still having this huge file in PS. All my Preferences in PS are without alteration from the stock settings of a newly installed PS application

Thank you

[wayneh92496952]

Also tried unchecking Use Graphic Processor and relaunching LR, editing in PS, etc. No change

Then I went to 8 bytes from 16 in LR preferences. All that happens is the Photoshop image is 34 MB.

[JohanElzenga]

wayneh92496952  wrote

Also tried unchecking Use Graphic Processor and relaunching LR, editing in PS, etc. No change

Then I went to 8 bytes from 16 in LR preferences. All that happens is the Photoshop image is 34 MB.

That is normal. The file saved from Photoshop is a TIFF file, and TIFF is not (lossy) compressed. If you started from a 1 MB file in Lightroom, then you probably started from a JPEG file, not a raw file. JPEG is a lossy compression, so the file size can be very small (at the expense of image quality).

[D Fosse · Accepted solution]

Yes, that's how jpeg works. It can shrink a file to around 2-5 % of uncompressed size. But the jpeg compression is not only lossy and destructive, it is also irreversible and cumulative. You should never resave a jpeg if it can be avoided.

Even raw files will grow. A raw file is a single channel at 14 bit depth. Demosaiced and processed into an RGB file it is three channels at 16 bit depth. A raw file of, say 40MB will save out to a TIFF of around 240MB uncompressed.

[wayneh92496952]

Thank you. Is there any reason that the window dialogue box asking if I want to edit in PS as a copy, original or edited LR image is no longer appearing?

[JohanElzenga]

wayneh92496952  wrote

Thank you. Is there any reason that the window dialogue box asking if I want to edit in PS as a copy, original or edited LR image is no longer appearing?

That dialog does not appear if you edit a raw file (because that will always create a copy). I’m not sure about HEIC images, but it is probably the same for those images too.