Digital BW, The Print

glemasurier wrote:

 >Am I destroying image quality by my workflow?



.




Yes.

JPG is, and has always been, what is called a "lossy" format;  every 
time the file is re-saved, data is dropped and lost from the image.  
Permanently.  Since a JPG image is already heavily compressed, and its 
composition starts out seriously compromised, the way in which you're 
working is only making a bad situation considerably worse. 

If you insist on shooting JPG instead of RAW, the very first thing you 
should do upon opening a file is to IMMEDIATELY save it in a non-lossy 
file format, such as TIF.  Close your original JPG file without making 
ANY changes to it, and apply all editing changes to your TIF version.  
Thus, your original file remains undamaged, and you can do anything you 
like to the TIF file without it suffering data loss. 

A JPG file, by the way, is NOT a digital negative-- it is a fully 
processed image file for which any number of critical decisions have 
already been automatically made by the camera.   The closest you can 
come to a digital version of a film negative is to shoot RAW, which 
produces an unprocessed file.  This allows the photographer considerable 
latitude in its "development" and there is no need to overcome and 
correct the "decisions" that are automatically made when the camera 
created a JPG file.  Another important plus-- at least for many of us-- 
is that a RAW file can be successfully enlarged to considerably greater 
dimensions, while maintaining considerably greater quality, than can a 
JPG file.  The image has far more data with which to work, and it shows. 

If, however, you really want to stick with shooting JPGs, at the very 
least do yourself the favor of saving your image in a non-lossy format 
before doing anything to it.  I've been using Photoshop since 1992 and 
always save my working files in the native PSD format, but many people 
seem to prefer TIF.  Just never forget that everytime you re-save your 
JPG file, it's dropping data that you can't recover.

Best wishes,

Shoshanna
http://www.pbase.com/shoshanna