What benefit .png over .jpg?

[Matt Graham]

From: James Dugger <james.dugger at gmail.com>
> GIF and PNG are as others have mentioned more for internet uses where 256
> colors or web corrected colors are adequate.

PNG is capable of storing 8 bits/channel and 4 channels, giving it a much
larger than 256-color palette.

> That said a best practice is always to shoot in raw. Raw saves all of the
> shot information (EXIF data) in the image for further manipulation later.
> If you shoot in jpeg this info not available to you.

Er... the relatively cheap digicam I bought in 2002 saved date/time, effective
f-stop, shutter speed, effective ISO, and various other things in an EXIF
block within the JPEGs it produced.  The slightly better digicam I have now
does the same thing, and it can't produce anything but JPEGs.  Did you mean
"raw format has no JPEG artifacts and can have more than 8 bits per channel"? 
Because that's true, and can have advantages if you're doing a lot of editing
in post.  Especially if you're shooting where the lighting is
terrible/inconsistent.

> I would consider the shooting and storing of images in raw the
> equivalent to [negatives in glass].

This is also true.  It just depends on how much disk space you'd like to
devote to storing stuff.  Since I'm not a professional photographer, I find
that 3500x2600 JPEGs at 90+ quality (about 2.2M per JPEG) seem to work great
for what I need.

> If you need a lossless compressible file format save a copy as a
> TIFF.

Or PNG.  

-- 
Matt G / Dances With Crows
The Crow202 Blog:  http://crow202.org/wordpress/
There is no Darkness in Eternity/But only Light too dim for us to see