Compression Raw to Jpeg

[Allan Monteiro]

Guys, I have a doubt about compression. I'm editing a Raw file of 21MB in 240 ppi in Lr and Ps and when I'm going to save it to Jpeg (using the quality option to 12) it goes to about 5/6MB. Is it shrinking too much or that's about what it should be? Because I edited other Raw files with the same size and when saved to Jpeg it got to 11MB.

I don't know if I unchecked something in Photoshop to help the compression or whatever. Can anyone help me out?

[D Fosse]

It's perfectly normal. Jpeg file size varies with actual image content. Flat areas compress much more effectively than busy high-frequency detail.

An argument could be made that quality 12 jpeg sort of defeats the whole purpose of jpeg. With jpeg, "max quality" is not actually max quality! There is still degradation, and it's still non-reversible. So considering that this is a destructive process in any case, you might as well get real payoff in file size. Going down from 12 to 8 dramatically reduces file size - but usually with minimal visual impact.

Jpegs are not suitable for archiving in any case. It's only used for derivative copies where bandwidth is an overriding issue.