We all know the conundrum. Be it saving your image for your website, or sending a set of images through the internet or even just for archiving your photographs. Just how much can we compress a jpeg file and the file is still useable for viewing on big screens or for printing.
Today we take a scientific look at exactly what you can get away with. For this experiment I used the latest version of Darktable (5.6.0). I first edited the raw file, and then I saved it at 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10% and finally 5% compression.
You can see the jpegs from this compression comparison in all their glory here
Here are the images for you to compare.
Here is a comparison of 100% vs 5% (The best and the worse)
Here is a comparison of 100% vs 70% (The best and a standard save for many)
Here is 90% vs 40%
As you can see from these examples, 70% seems to be the point where the jpeg is most useable, although of course 80%-100% are better again. You have to ask yourself how much people are going to notice this difference.
Typical File Sizes
Based on a modern, full frame camera and 24.5mp image files, the file sizes are as follows.
100% (Uncompressed) = 10.3MB, 90% = 1.49MB, 80% = 876KB, 60% = 656KB, 40% = 392KB, 20% = 272KB, 5% = 192KB. As you can see, there is quite a difference between the uncompressed and compressed files!
Conclusion
I usually save jpegs at between 70-90%. For client work with weddings and portraits I almost always save the jpegs at 90%. I rarely, if ever save a jpeg at 100%, just because when you are saving thousands of images, it is surprising the savings in space than 90% can make.
You can see the jpegs from this compression comparison in all their glory here
My name is Mark G Adams and I run Photography By Mark G Adams. I am a professional photographer from South Wales, shooting weddings, events and portraits as well as running meets and workshops. For fun I like to shoot landscapes, wildlife and occasionally do street photography. Enjoy my website as I share my knowledge learned over decades of working and having fun in photography – This Is My Personal Website
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Interesting comparison. For web use, image dimensions often have a bigger impact on file size than JPEG quality alone. It would be interesting to compare both variables together, since the reported file sizes are difficult for your readers to interpret without knowing the image dimensions.
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Thanks Marc. It’s more a look at how compression affects the image (regardless of the image dimensions). The file sizes are just to give an idea on an image that never changes size. They can all be downloaded from the link to scrutinise.
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A good post Mark. I compress to about 40% (I post too many pix, I know). It seems to be decent quality on a 16:9 screen. Have a great day. Allan
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Thanks Allan. Have a great week.
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