Compression in JPEG files in digital cameras

HEMI-Powered wrote:
OK, but again, Thomas, I interpreted the OP as being a fairly new
digital owner and thus a novice on file types, so I just
mentioned TIFF as an alternative if their camera supports it.
TIFF is universally recognized, although news readers cannot
decode it in line, and about its only drawback other than large
size is that if you want to save EXIF, you cannot use LZW
compression, or at least AFAIK.


Hardly any cameras support TIFF. Yes, you can use EXIF with LZW ... the are
completely unrelated as far as TIFF is concerned.

I don't want to start yet another religious war about bit-length.
It seems to me, though, that 16-bit color - no matter where it
comes from or in what format(s) it is saved to - is a subject for
VERY advanced people who have software that can correctly
manipulated it. And, the person behind the camera and behind the
keyboard also has to be quite a bit more knowledgeable to gain
any real advantage over 8-bit.

It doesn't take VERY advanced to use 16-bit. Anybody who wants to shoot
camera RAW should understand a workflow that [potentially] uses 16-bit image
manipulation.


But, I have a question for you Thomas: everytime 16-bit color
comes up, part of the raging debate is that most/all cameras and
apps, including PS CS2, really only have 11 or 12 bits of real
information, the others being basically just noise that is
ignorned by the software. Has that improved in ANY format,
whether it be JPEG, TIFF, or RAW? i.e., is something closer to
16-bit or true 16-bit now available for them with deep pockets?
If so, could you just give me 25 words or less as a heads-up on
today's status so I can go looking? Yes, I know Google is my best
friend, but on things like this, it is like the old saying "I
don't even know enough to ask an intelligent question", and it
goes to the extreme frustration I have had for well over a year
trying to find a RAW for Dummies kind of book that isn't keyed to
PS CS2 or Elements that will at least get me started up the
learning curve.

You don't get more information by converting a 12-bit RAW file to a 16-bit
TIFF (or PSD). You would definitely lose information if you converted to an
8-bit TIFF and you would lose even more information if you converted to an
8-bit JPEG (all JPEG images are 8-bit). As far as the benefits of a 16-bit
workflow, I will leave that for another discussion which has been hashed about
here before and is available in many books and online resources.


In any event, I find these threads fascinating but always feel
bad for the poor OP who has some simple or easy question like
he does the size of the image or compression cause image
problems? I kinda doubt that level of knowledge is ready for all
of the sophisticated answers the more experienced folks have been
bantering about. Yes, /I/ learn something, but a rank novice just
gets totally snowed under and may feel so intimidated as to not
even come back for a 2nd round of questions.


The simple answer to a "simple" question is "yes". But, if you want to know
why, then you have to read.

--
Thomas T. Veldhouse

We have more to fear from the bungling of the incompetent than from the
machinations of the wicked.