David J Taylor added these comments in the current discussion du
jour ...

Both ordinary JPEG and TIFF are both 8-bit. I only mentioned
TIFF, either the uncompressed kind or LZW, as an alternative
to the OP or any lurkers who want a simpler lossless file
system than RAW,

OK, I appreciate that.

David, occasionally, I save to simple Windows BMP or maybe PNG,
and on rare occasions, I will save to PSP's proprietary pspimage
format. Which goes to my constand wonder if the OP ever gets much
out of a thread when it suddenly gets quite technical, well into
theory and away from pragmatics, and we all have fun but I think
they shake their head and slink away. Can't prove that, I just
"feel" it.

Yes, David, as recently as this spring as I was getting ready
for the summer car show season. It isn't that I dispute you
at all, you're much more skilled and knowledgeable than me,
it is that MY experience shows that the amount of work
necessary to get an 8 MP image down to my 1.5 MP finished
size without introducing aliasing and other undesirable
non-compression artifacts just isn't worth my time and
effort.

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.

Yes, I would expect that when using less than the native
resolution of the camera, the images will be slightly sharper
(meaning that there are fewer pixels covering a black-white
transition), and therefore more likely to show JPEG artefacts
at a particular compression (quality) level. So when using
lower resolution, stick with the highest JPEG quality. Makes
sense to me, anyhow!

Again, not for you David because you understand what I try to do
and why, but for them lurkers, about 99 44/100% of my images are
only displayed with a screensaver or slide show in Windows and/or
posted to Usenet. That is why I seldom save larger than 1400 x
1050 and never larger than 1600 x 1200. That said, I'm well aware
of what happens with that low a PPI trying to print to borderless
8.5 x 11 glossy paper, but it does satisfy my needs. And, I have
found that Windows and common slide show programs that "pixel
resize" rather than mathematically "resample" for speed of
display totally mangles an image much larger than my current 1280
x 960 monitor. Now, I do have plans to upgrade to a 24" or 26"
LCD about the time I get my next PC built, maybe late next year,
so I will experiment with the higher resolutions images at that
time.

One other comment wrt posting to Usenet. I simply do not have the
time to save at a large size for myself but resample smaller to
post, therefore I also do not have the time and energy to "do it
right" so as to minimize inevitible aliasing of fine details on
the chrome, badgees, and character lines of my car pictures in
order to meet NG FAQs. It all boils down to this: each of us
should do what works best for us, and I believe you support that
notion. I do stray into "contrarian" mode with novices, though,
because I can tell by their meager OP that they've been snared by
the marketing hype that more mega pixels means better pictures,
without regard to the dozens of other factors involved.

Thanks for your observations and have a great week!

--
HP, aka Jerry