All overall correct but RAW is not BMP today. Could be that
there was cameras what used BMP like RAW format but what
I  have seen uncompressed format is TIFF or RAW.

Raw format today is actual data from every pixel and
 at least 12 - usually more bit per color pixel.
That allows You to do corrections after downloading
pictures to camera if You have software like Photoshop.
Usually software what comes with camera allows
to do corrections when You download/convert them
to You computer but they are less possibilities
than in Photoshop. Exception is Fuji Finepix E550.
It has RAW format but converter don't have any
control to change image.


Toomas




----- Original Message -----
From: "Don Penlington" <[log in to unmask]>


> David writes:
>
> <<BMP is the Windows image format which closely corrersponds to what most
> digital camera makers call "RAW" -- the uncompressed actual pixel values.
> Not all cameras offer this choice, but if you can afford one that does,
> that's a very good choice.>>
>
> Whilst what David says is technically correct, I beg to differ when he says
> that .bmp format is the "best" choice.
>
> That format is pretty obsolete now, for most practical purposes for most of
> us.  And, no, simply opening and closing a jpg file does not result in any
> deterioration, which I think was the question originally asked.
>
> You'd only need to resave it if you were making any alterations to it. Then
> there will be some more loss, which may soon become noticeable.
>
> Whilst it's true that you can't put back what has been lost (or was never
> there), it's amazing what the right software can actually "put back" by
> intelligent interpolation. Indeed, good software can certainly give that
> illusion by "improving" the original quite drastically, at least for
> computer screens. Perhaps less so for large prints.
>
> The reason that .bmp is now seldom used, except perhaps by professional
> photographers requiring the highest quality print material, is that the
> files are huge compared with the jpg format.  I find that compressing a bmp
> photo to around 65%-80% jpg is for most practical purposes satisfactory.
> This reduces the file size from over 2 Mb to about 50 Kb. Maybe if you have
> a huge hard drive and space is not a factor, and you don't intend sending
> your pix to anyone, then there's no reason to do so.
>
> Loss of quality?  You'd need to blow them up to many times the screen size
> to see it.  Even then you need to look hard. An 80% jpg compression is
> almost undetectable without a magnifying glass.
>
> So, unless you are into the professional stuff, for most practical purposes
> stick with jpg.  You won't notice any difference.
>
> If, on the other hand, you intend to make high quality large prints, then
> you'll need the very best resolution.
>
> Personally, I never use my camera's (modest) highest resolution, as I only
> have to downsize the photos anyway when I move them to the computer.  The
> only exception to that might be where I use optical zoom to its fullest,
> and suspect that I'm still going to have to do some severe cropping
> later.  Then you do need max resolution.
>
> But then, my requirements are clearly much different from Davids.  It all
> gets down to what your expectations are.  I doubt that many of us are, to
> quote David: "serious digital photographer(s)".
>
> To test all this once again, I've now experimented with a  .bmp photo I
> downloaded yesterday from a "serious digital professional photographer". It
> is a file 1.37 Mb in size, about 600x750.  Working with a copy, I reduced
> the copy to 65% .jpg compression. This gives me a file 40 kb in
> size.  Looking at both side by side in fullscreen, I can detect absolutely
> no difference in fine detail (it's a portrait photo taken with oblique
> light, with much fine detail).  Blowing each photo up to 6x screen size, I
> can still detect no difference in quality, though each is now becoming
> rather pixellated. At that size, the pixellations are very slightly
> different, though it's impossible to say which is "better".
>
> Working with high quality prints probably is a completely different
> ballgame.
>
> Don Penlington
>
>
>
>
>
>
>
> From the Beach at Surfers Paradise in sunny Queensland.
> Computer tutorials, local scenery,  and other things at my website:
> http://users.tpg.com.au/deepend/index1.html
>
>      "Hold No Punches.." Rode brings you great shareware/freeware
>        programs with his honest opinions in this weekly column.
>                       http://freepctech.com/rode
>

      "Hold No Punches.." Rode brings you great shareware/freeware
        programs with his honest opinions in this weekly column.
                       http://freepctech.com/rode