Is this normal?

[Glenda]

Using Photoshop CC, I was resizing an image for posting and found it says the size of quality 6 is larger than quality 7. I tested on a few other images and had the same result.

Screen Shot 2019-10-05 at 8.37.20 am.png

Screen Shot 2019-10-05 at 8.37.35 am.png

[ameerat42]

It sure seems odd! I'd suggest saving a version at each setting and then
checking with File Manager.

- - - Updated - - -

---Having achieved the status of a dead cat, I got these results, too
NOTE that the differences in respective file sizes between Photoshop and File Manager
is due to how much actual disk space (because of unfilled parts of disk sector) each
file takes up. So the actual 151.6 KB of file size (scrawled over with the red line )
takes up 168 KB of sectors, etc.

But that doesn't explain "why" for the unexpected result...
DSC_3993aclrsave--test.jpg

[Glenda]

Certainly seems strange when going from 10 > 9 > 8 etc reduces the size each step.

[fillum]

I've noticed this in the past as well. It never bothered me - I've assumed there is some change in the compression algorithm that results in this 'quirk'. (Perhaps at higher quality the algorithm is a little 'harder' to keep file sizes down? Quality 6 -> 7 is also the halfway point so that might have something to do with why the change happens here?)


Cheers.

[farmmax]

My photoshop CS5.1 doesn't do that. It behaves normally, and 6 is smaller than 7. But, my format option is "Progressive". Do you want to try that instead of Baseline (Standard) and see if that gives the result you expect? It probably doesn't matter all that much

[Glenda]

Thanks fillum and farmmax.

Fillum - it doesn't particularly worry me. I did have to go down to 5 to get under the 400k but the IQ seemed OK.

Farmmax - I just tried changing this to progressive and the same thing happened although with progressive the file size was slightly higher.