12
Replies
It looks like my jpgs exporting from Lightroom Classic are getting compressed... I don't think that I changed any settings but the exported files are much smaller than the originals and I'm not sure that the quality will be as good for printing.
JPG file size is not an indicator of quality. How can you determine the quality of an image that is needed for printing? You need to have the proper number of pixels per inch when you print; again this has nothing to do with file size. For a 4x6 or 5x7 print, you might need 300 pixels per inch. For larger prints, you can get away with fewer pixels per inch. (In addition, JPG is a compression technology, JPGs are supposed to be a lot smaller than the original)
I want to export my jpgs as high quality as possible and I''m having a nightmare having designed a photobook with Blurb which contains hundreds of photos - I don't know which ones were exported at high resolution so it looks like I will have to go through every photo at this rate and replace them with newly exported versions...
If you are creating the Blurb book from within Lightroom Classic (are you?) then LrC takes care of all of the quality business, you don't have to set any settings. But you don't have to export a JPG first for LrC to create the book, you can select the original (edited perhaps) from within LrC, no exporting needed.
To evaluate image quality, export full size jpgs, import them back to Lightroom, and compare with the original at 100%.
By @Per Berntsen
Assuming there is no Develop preset applied at Import, and the default settings of all sliders are at zero, then yes this will work. If there is a develop preset applied at Import, or even non-zero default settings for the sliders, then this does not work.
As I said before, the purpose of the jpg format is to produce smaller files.
And the file size of a jpg does not tell you anything about image quality.
There are three factors that influence the file size of a jpg:
Pixel dimensions, quality setting when exporting, and image content.
Image content can have huge influence on file size. Images with lots of busy, sharp detail (or noise) will have a much larger file size than images with predominantly flat, smooth, or out of focus areas.
See the two images below, which have the same pixel dimensions, and are exported with the same quality setting.
One is almost 6 times larger than the other.
"The weird thing is that the files are now exporting from Lightroom bigger than the originals..."
This can happen if your original is a jpg, and you sharpen it in Develop, and/or use Output sharpening.
If the image is noisy, and you sharpen the noise, or if you use a high Clarity or Texture setting, this will also contribute to a larger file size.
2.72 MB
447 KB
I've tried this - there is no difference that I can see between the images by eye... But there is a big difference in size - e.g. 8.54MB vs 1.43MB
By @sallyd70179725
No difference seen by a human eye! Sounds like there is NO noticeable quality problem.
AdChoices