Jpeg Comrpression

[David Eichler]

This isn't strictly a Lightroom question. However, I mostly use Lightroom for creating jpegs from Tiff or Raw files. My website provider suggests that I limit the file size of horizontal images to 120kb, and vertical images to 70kb. The constraints of the images are 920 pixels wide by 560 pixels high.  I use a Canon 5dII, so the files are big. I find that with some images I can't get anywhere near to the recommended file sizes without serious jpeg compression artifacts, which, to me, are unacceptable for high quality work. So, I go ahead and use much larger file sizes, sometimes as much as 400 to 500kb, using a Lightroom quality setting of maybe 80 to 90. This doesn't seem to create slow loading of my website with my medium fast cable internet connection, but I am concerned about what other viewers, who may be on slower connections, are experiencing. I have tried a dual step downsizing process in Photoshop, advocated by someone who works with medium format digital images, but that didn't seem to offer any significant benefit for the extra work involved. Any other suggestions for creating acceptable quality jpegs for websites at the specified image and file sizes?

[Josh-H]

This isn't strictly a Lightroom question. However, I mostly use Lightroom for creating jpegs from Tiff or Raw files. My website provider suggests that I limit the file size of horizontal images to 120kb, and vertical images to 70kb. The constraints of the images are 920 pixels wide by 560 pixels high.  I use a Canon 5dII, so the files are big. I find that with some images I can't get anywhere near to the recommended file sizes without serious jpeg compression artifacts, which, to me, are unacceptable for high quality work. So, I go ahead and use much larger file sizes, sometimes as much as 400 to 500kb, using a Lightroom quality setting of maybe 80 to 90. This doesn't seem to create slow loading of my website with my medium fast cable internet connection, but I am concerned about what other viewers, who may be on slower connections, are experiencing. I have tried a dual step downsizing process in Photoshop, advocated by someone who works with medium format digital images, but that didn't seem to offer any significant benefit for the extra work involved. Any other suggestions for creating acceptable quality jpegs for websites at the specified image and file sizes?

David, I have come across this myself whereby my website provider recommends similar sized jpegs for my own site. Problem as you point out is that they are full of artifacts at those levels of compression. Like you I go with much higher quality and sized be damned. I cant offer you a solution (I actually dont think there is one - but I am all ears if someone has a golden bullet to this problem). I just thought you would like to know you are not alone 

[feppe]

This isn't strictly a Lightroom question. However, I mostly use Lightroom for creating jpegs from Tiff or Raw files. My website provider suggests that I limit the file size of horizontal images to 120kb, and vertical images to 70kb. The constraints of the images are 920 pixels wide by 560 pixels high.  I use a Canon 5dII, so the files are big. I find that with some images I can't get anywhere near to the recommended file sizes without serious jpeg compression artifacts, which, to me, are unacceptable for high quality work. So, I go ahead and use much larger file sizes, sometimes as much as 400 to 500kb, using a Lightroom quality setting of maybe 80 to 90. This doesn't seem to create slow loading of my website with my medium fast cable internet connection, but I am concerned about what other viewers, who may be on slower connections, are experiencing. I have tried a dual step downsizing process in Photoshop, advocated by someone who works with medium format digital images, but that didn't seem to offer any significant benefit for the extra work involved. Any other suggestions for creating acceptable quality jpegs for websites at the specified image and file sizes?

You need to find a compromise between quality and size. I go for 75 since higher than that shows diminishing returns, becoming pointless after 80. I double-check each image in case there's a need to increase it.

[jrsforums]

Jeffrey Friedl did a great piece on LR jpeg compression:

"An Analysis of Lightroom JPEG Export Quality Settings"
http://regex.info/blog/lightroom-goodies/jpeg-quality

John

[feppe]

Jeffrey Friedl did a great piece on LR jpeg compression:

"An Analysis of Lightroom JPEG Export Quality Settings"
http://regex.info/blog/lightroom-goodies/jpeg-quality

Incidentally the same link as in my post.