Digital BW, The Print

> From: Clayton Price
> 
> One question though --since you're saving your edited images as  
> quality 12  jpg's,
> what would you do if, for example, you had a saved final image which  
> you printed
> out at 16 x 20, and later you decided to print it as a 30 x 
> 40?  As I  
> see it, you'd have
> two choices - 1) interpolate upward your 8 bit jpg, which not only  
> will be problematic
> by uprezing a compressed format image (even at 12, it's compressed)  
> and the additional
> potential problem with lossy formats, of additional data loss each  
> time you make changes.
> Or - 2) going back to the RAW or DNG (saved variations in (I think  
> you meant?-- .XMP sidecar
> files) and basically, starting all over again.
> 
> Why not simply save as tiff or psd  16 bit files, which will cause  
> far fewer problems, even
> though the file size is larger, and save you a lot of time?

Because I don't believe that quality 12 JPEG _does_ cause any problems. I've
done A/B comparisons, pixel peeping at 1000%, and I've never been able to
see any meaningful difference between the JPEG and the original uncompressed
data.

I also don't up-size in Photoshop according to the size I want to print.
That is, I don't explicitly interpolate the image up to a larger number of
pixels and then print. I just print, and let the driver map the image pixels
to the dots on the page. I've never had a problem with that. (I mentioned
the moire exception earlier, but that's a very rare occurrence.)

I'm also not convinced that the amount of sharpening I'd want to use would
depend upon the print size (except of course for making really tiny prints
where I have to downsize). I assume that if I print larger, it's so that
people can stand further away.

> Unless storage is a real problem, my own method is still another  
> alternative, and that's
> to retouch and optimize most of my image finals at an even larger  
> size than I think I'll ever
> want to print them. In that way, downsizing for any print size will  
> basically minimize any
> retouching that possibly could show at 100%. It's a little more  
> necessary for me to do that,
> since much of my work consists of photo collages, and sometimes  
> master images
> (with all the layers) can be upwards of two gigabytes.  I've had to  
> get external storage up into the
> terabytes range, and it's expensive, but seems to be the best  
> solution for me.

Well, if you can see a difference by doing that, go right ahead. I'm
skeptical. An image only has so much spatial high frequency content, and
up-sizing doesn't manufacture any higher components (unless you use some
algorithmic resizer, like Genuine Fractals). But perhaps you do more
complicated stuff. I've always been satisfied with the results I get from
editing at the original size.

-- 

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@...