Small jpegs

Report · Mar 24, 2022

Hello!

I just bought the trial version of LR Classic to work with on my new MAC with M1 chip.

Now, when I develop a RAW file of, let's say, 30 MB and hardly make any changes, the exported Jpeg is no bigger than 3 MB!
When I was using LR 6, for example, the Jpegs were between 10 and 20 MB.

What do I do wrong?

Thank you!

Report · Mar 24, 2022

What resolution did you use in LR6 and what are you using now? Are they identical?

What JPG quality did you use in LR6 and what are you using now? Are they identical?

I use always JPG quality of 75%, I don't see any degraded files quality.

Do you still have LR6 on your computer, best case you export the same file and check the picture quality and resolution of both outputfiles.

Ralf

Report · Mar 24, 2022

Hi Ralf,

Thank you very much for your answer! I checked the resolution and LR 6 was set to 100%, while LR Classic was set to 60%. That explains the difference!

Kind regards,

Marcel

Report · Mar 28, 2022

Hello Marcel,

I did once a small study.

I took 100 photos, different subjects and exported them from Lightroom Classic 11.x

Base photos were DNG, converted from CR2 (Canon 5D Mark IV).

All other settings were identical, I only changed JPG quality.

The result: The JPG quality does not correlate 1:1 to the final filesize of the exported JPGs.

My recommendation would be:

1. Check what resulution you really need. I view most of my pictures on my laptop, therefor I went with 2700x1800px. If you use a 4k screen you should use higher resolution.

If I need them in higher resulution / quality I can still export them for this special purpose, because I still have originals in LrC.

2. Export a few examples of your pictures in 100% and 75%, change there names during the export in 100P_001, 100P_002 ... 075P_001, 075P_002. Renaming will ensure that you know the settings and that Lightroom will import then, without rejection.

Then import these JPGs back in Lightroom and compare them side by side at magnification 100%, 200% & 300%. As soon as you don't see any fragmentation in the JPGs you found your limit.

If 75% is not OK go higher, if OK go lower.

Based on this limit you can then define your export setting.

Let me know at what level you saw the first fragmentation, that is no longer OK for you.

Ralf

Report · Mar 24, 2022

A relatively small file size is not necessarily a bad thing. A large file size is not necessarily a good thing. It depends on your functional requirements, which may or may not have anything to do with file size.

There are several factors that affect file size for JPG. Exporting cannot be done 'right' or 'wrong' in itself - either so far as file size, or so far as other attributes - it can only be done suitably or unsuitably, towards some usage requirement.

Do you even want a JPG or is a lossless format such as TIFF more suitable - e.g. if this will be further edited in another application.
Containing more or less picture detail (technically as to focus or camera shake - or as a subject, say if it's a very foggy landscape or shows lots of complex fine pattern) affects JPG file size, other factors being equal, with more detail tending to make a bigger file - sharpening can affect this also.
Being more or less noisy affects JPG file size, other factors being equal, with more use of noise-reduction tending to make a much smaller file from the same capture.
Pixel dimensions are the most important aspect affecting file size. Specific requirements for that - it is possible to have too many pixels for a purpose, just as it's possible to have too few for that purpose. Say the usage is viewing in a website: if you supply the appropriate number of pixels for that rather than aiming for the maximum possible, then your image will not need to be heavily scaled-down by the website - which often produces a less attractive final presentation on screen, than when Lightroom Classic has done the needed downsizing itself.
JPG saving quality is really secondary in importance IMO - it does affect file size but it cannot work miracles so far as image quality, whatever that may even mean in a given context. First get the pixel dimensions suitable, get the image processing including detail panel settings suitable, set suitable output sharpening, try a reasonable saving quality (say 80%; higher than this has minimal effect for image quality but disproportionally makes the file larger) and see what the emergent file size is. If you need to set a very low saving quality in order to meet required file size limit, likely you would be better off resizing to fewer pixels, and then using a more normal JPG saving quality.

Even 3MB is relatively large for JPG: if it looks visually as you want, and suits the usage OK, then I suggest: be glad it is not 10MB or more!

Report · Mar 24, 2022

Hi Richard,

Thanks so much for your extensive answer! I checked the resolutions and in LR Classic it was set to 60%. I changed this to a higher percentage and everything is fine.

Kind regards,

Marcel

Report · Mar 24, 2022

Resolution is different than the % JPG saving quality.

If you are not resizing the image at all, changing the Resolution figure (Pixels per inch or pixels per centimetre) does not affect the pixel dimensions and therefore does not affect the file size. And if you are resizing the image to stated overall pixel dimensions, then the Resolution figure also does not affect the file size.

It is worth making a visual check to see whether increasing JPG % saving quality is actually beneficial. Typically there will be a slight improvement visible when moving from 60% to 80%, and almost no further improvement beyond that - and that, only when viewing the image at 100% zoom. If the image is going to be viewed "scale-to-fit" on screen, then perhaps an export that is resized to the right number of pixels to suit this usage, would be better. Even then, 80% is IMO the "sweet spot" so far as economy of file size, while still giving a very good reproduction of the photo, meeting all usual expectations.

Report · Mar 28, 2022

Dear Richard,

Thank you for your answer! This has been very helpful. I will see how it goes if I export the images with 80% file size.

Thanks,

Marcel