Originally posted by BrianR It is indeed. As a heavy LR user, I really needed that.
Some cameras output crazy huge JPEG files that are effectively lossless. For example, they have settings like NORMAL, FINE, SUPERFINE, and if you set it to super then the files become enormous. And yet, the only possible way to see any difference between fine and super is by taking a shot that's all noise and then pixel-peeping it. Super can capture the noise accurately, pixel-for-pixel, but for any other kind of subject matter it's indistinguishable.
It's been rumored that some cameras are designed to produce huge JPEGs simply because people now associate bigger = better, so the superfine option would be a way to appease that belief, even though it has little-if-any practical value.
I'm a believer in JPEGmini. I've been habitually exporting images from Lightroom at 85% -- which, according to the article I just looked at, that's the second-highest level on LR's 12-step scale. Then I've been running them through JPEGmini. It cuts them down to sometimes half the size, while the visual change is very minimal. I've tried pixel-peeping the files, and sometimes it's just barely possible to pick out some difference at that level. (Maybe I should just export at 100%, if I'm going to use JPEGmini on them anyhow.)