Bill Tuthill added these comments in the current discussion du
jour ...

I never revisited the lower quality, i.e., higher
compression, option on my Rebel because I could easily see
JPEG compression artifacts at a large enough percentage that
I didn't want to risk blowing otherwise good pictures. As you
and others have so correctly pointed out, memory is so cheap,
that it really doesn't matter if the image is 500KB or one
meg.

Could you please post an impage where you can easily see JPEG
artifacts at the highest quality your Rebel produces? Thanks!

The reason I ask is, it's hard for me to see JPEG artifacts at
Q 95 and 1x1 or 2x1 chroma subsampling, and I'm good at
seeing JPEG artifacts.

This isn't a binary NG so I can't post here, but I also do not
keep an accurate inventory of those images I may see artifacts in
out of my camera. And, by the time I have finished with an image,
I have taken the technical steps I think are prudent to eliminate
all but the most minor defects by always re-opening a just-saved
image to check for the two biggies: artifacts as in streaks,
blobs, and blotches, or aliasing, aka jaggies.

Incidently, I don't think I ever said I've seen an artifact in my
Rebel's higher of its two available quality settings. What I said
was that some significant percentage at the lower setting DID
exhibit artifacts. There are many factors involved other than
just pure over compression, but I would hazard a guess that at
the lower quality level I see at least 5% that have damage,
sometimes 10% or more. And, since I cannot predict at the time I
am shooting which 5 or 10% will be damaged, I go for the quality.
Memory is cheap, my time is not.

As to Chroma subsampling, my normal setting is 1x2. I will lower
the compression number and/or change to 1x1 (none) until I can
eliminate the damage as described above.

--
HP, aka Jerry