[Leica] Now RAW vs JPEG

[jonathan at openhealth.org (Jonathan Borden)]

  Ted Grant wrote:

> Tina and Jonathan
>
> WOW!!!!!!!!! :-)
>
> Now I gotta tell you, you folks are beginning to scare the  
> daylights out of me with all this stuff!! Heck I may just have to  
> keep all my film cameras after all and return to Mother Nature  
> film! ;-)
>
> Well I hadn't really left it, as it's part of me and breathing! :-)  
> So I still always have a film camera in the bag and rolls of film.  
> I mean if I didn't I'd surely be struck down by a mighty sword of  
> wrath from the Great Film Father in the sky! ;-)
>
> It sure is beginning to look like film was much easier, at least I  
> knew what the heck I was doing. OK, OK most of the time. ;-)
>
> But all this stuff is near scaring me off because it works like this:
>
> "Tell me and I will forget.
> Show me and I may remember.
> Involve me and I will understand!"
>
> But I have to add... "Confuse me and I'm dead in the water!" :-(

I think I can easily explain away the confusion.

There are a bunch of manufacturer specific "RAW" formats, that store  
"full fidelity" image information.

JPEG is what is known as a "lossy compression" format, in that it  
throws out most of the bits in order to make the file smaller. In  
many cases those bits might be important (e.g. if you are printing a  
large photo) in other cases the bits aren't so important (e.g. if you  
are looking  at small image on a web browser, and particularly if you  
have a dialup internet connection).

TIFF is what is known as a "lossless" format in that it keeps all the  
bits (they might be ZIP compressed).

DNG is Adobe's latest version of TIFF in that it has a whole bunch of  
metadata tags defined specific to the needs of "digital negatives".

My issue is with proprietary RAW formats e.g. Canon's or Nikon's or  
Minolta's etc etc. because they are likely to change over time and  
there might not be software available to deal with these formats in  
the future.

DNG/TIFF is a great option for archiving digital negatives because it  
uses a very well known format for which there is abundant software.  
Suppose a new computer comes out, with a new operating system... you  
can probably just recompile the TIFF software for the new platform.

So basically when I say "use TIFF" it is the same as saying "Convert  
your proprietary RAW images to DNG" for long term, high quality  
archiving.

Jonathan