“Photographer Jamie Gillies recently went down the deep, dark rabbit hole known as “JPEG quality.” Now that he’s emerged on the other side, he’s sharing the knowledge that he’s gained so that you too can understand how JPEG quality works, and what export settings to use for the best possible results.”
Read the rest at PetaPixel: A Deep Dive on JPEG Quality and What Export Settings You Should Use
Let me forewarn you, I found the beginning of Gillies presentation a tad annoying (maybe even a little creepy), but stick with it as it does get infinitely more interesting. View it in full screen either on PetaPixel or on YouTube and in High Definition if you can. On the YouTube page you’ll also find a written summary of his recommended export settings. And at the start let me say it was not my intention to replicate what Gillies did, but I did use 80% as the target for the full-size, 6000 x 4000 pixel image I used.
First an update on JPEGmini. You can download the trial and buy it, but it’s no longer possible to convert images directly on their site. If you are a professional photographer looking to reduce the amount of storage your thousands and thousands of full size images take up, like Gillies, then it’s probably worth the investment. Not that US$89 is going to break the bank (particularly if your camera equipment cost you thousands of dollars), but for me it’s not a worthwhile investment. Retired hobbyist photographer, remember?
In my previous post I mentioned that I wanted to see how well my newly acquired Affinity Photo could compress an image and see what file size I ended up with compared to the other two image editing programs I currently have, PSE2018 and PSP2018. The full size 6000 x 4000 pixel image weighs in at 10.6MB.
As WordPress.com doesn’t keep or display image XMP or IPTC information in the image, please note:
All the images in this post are Copyright © 2020
Jen Tocker, All Rights Reserved
Onward! The full size JPG can be seen here for comparison (PW: name of this site, all lowercase with no spaces and the year this was published). Click it a second time to view the full-size image in your browser. FWIW – You can also follow this post without viewing the full-size image.
The content column on this site’s theme, AltoFocus, is 770 pixels wide and each image was inserted in this post at “full size”. All images are 6000 pixels wide, so in order to see that, please click on each image which will open it in another tab and then click again to view it full sized. These images were saved at 80% from the same 66MB PSD file.
The MB sizes mentioned in each caption are as they appear on my computer. When looking at the images in my Media Library, WordPress.com has rounded those figures up or down (1, 2, 1 respectively).
For those interested in the image EXIF info:
At 80% I can’t discern much difference between them or even between them and the original 10 MB photo. There’s a bit of graininess overall but given that this photo was taken handheld at 6:15 PM in waning light, it’s pretty reasonable at 400 ISO. (That’s another thing I need to overcome when I take photos in low light; my analog camera brain says 400 ISO is pretty high, but the camera can take it up to 12800.)
Now 1.8 MB, 1.5 MB and 1.3 MB are still too darn heavy if your purpose is to display it on a website, especially if you are viewing on a mobile device. Every image of that size you insert in your site increases your site loading time and that’s something you want to avoid. By contrast the header image in this post is 1500 pixels by 1000 pixels and weighs in at 163 KB. Here it is again, inserted at “full size” and clicking on it will open the image in a new tab:
Here then are my conclusions: Affinity Photo didn’t produce the smallest file size when exported at 80% (1.5 MB) and didn’t show noticeable degradation of image quality, but PSE 2018 still produced the smallest file size of the three programs I have. Additionally, if I want to save on storage space and improve loading time on my website, I’d resize images to double my theme’s content column width and optimize them in an external image editing program before uploading them to my WordPress.com website. However, ultimately it comes down to the image size you want to display on your website, keeping in mind both your theme’s content column and that more people than ever use mobile devices for browsing.
It’s also possible that my aging eyesight sees everything with rose-colored glasses, so if you see something very different while looking at these images, please leave a comment and let me know what you see!