In article , Mayayana
wrote:

| 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.

of course it does. anything coming out of a camera contains exif data
(unless it's a super-****ty camera).

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.

why would anyone use bmp?

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 shoot raw but others might not.

posting obviously must be jpg but for printing, they're directly
printed from raw.

there's nothing wrong with shooting jpeg, especially if the images are
going to not be processed all that much. for example, ebay photos.

| Isn't the whole idea of saving as JPG outdated?
|
| of course not.

Because JPG is by definition low quality.

no it isn't. high quality jpeg is indistinguishable from the original.

At the
time cameras were coming out PNG was not widely
supported, and PNG doesn't compress as well.

png still doesn't compress 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.

nonsense. jpeg is *designed* for photographs. what do you think the
second letter represents?

where jpeg doesn't work well are synthetic images, such as computer
generated graphics.

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.

then set the quality higher.

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.)

it's close enough to 0 to where it is not noticeable (assuming you
choose the highest quality).