Quote Originally Posted by Ed Sukach The color differences
between brands of enlarging lenses, and between different lenses
of the same brand, would not surprise me much - but then after
the years I've spent, it takes quite a bit to surprise me. I
still don't understand a great deal - I'm just not surprised
that there are things I don't understand.  It's interesting that
you cycle the enlarging lamp a few times to "warm it up". I
analyze the color characteristics of the lamp in my enlarger
before every session, and randomly, during the session, and I've
never found that the ambient temperature that exists in the
optical system affects anything worth mentioning. What lamps -
halogen, incandescent - or? are you using?  Between the three
lenses I use - two Rodenstocks and one Schneider - I only see
3-4 cc difference. More would not surprise me, though (see
above). Variations in color balance of the negatives and paper,
and chemistry - are more pronounced .. and analyzing for those
would mask other variables.  I