| But that implies it was taken as JPG.
|
| no it doesn't.
| the exif data is preserved when editing.

So RAW contains EXIF data? I didn't know that.
Personally I always save anything as TIFF or BMP
until such time as I need to transfer a small file for
online use. I don't pay much attention to EXIF data.
So it hadn't occurred to me that RAW may embed
EXIF data.

So... you have EXIF data in all of your images, and
RAW contains EXIF data? Do you take most images
in RAW and save them that way until posting them
online or printing?

| I haven't
| researched different cameras, but JPGs I see
| seem to generally show over-compression when
| viewed at full size. They look great viewed small,
| but when viewed full size it's clear that a lot of
| data is already gone in the initial save. So even if
| this image were not oversharpened, little rectangles
| would probably still be visible at full size.
|
| only if it's a low quality jpeg.
|
| Isn't the whole idea of saving as JPG outdated?
|
| of course not.

Because JPG is by definition low quality. At the
time cameras were coming out PNG was not widely
supported, and PNG doesn't compress as well. JPG
was/is supported on all major OSs. JPG was really
designed to optimize file size with "tolerable" loss of
quality. Great for the Web, but questionable
for photographs.

I got thinking about this last week because I
was testing out some image resizing code and had
some test images. They were not top quality, but
they're pretty good:

Panasonic DMC-ZS25
4608x3456 at just under 6 MB each. I expect they'd
look fine printed as postcard size, but when zooming
in, and in some cases at normal size viewing, I can
see rectangles. I doubt that any camera taking JPGs
saves the images with no loss at all. I'm not sure it's
even possible to save a JPG with zero loss, even at the
"100" quality level. (Though I'm not certain about that.)