"David Nebenzahl" wrote in message
s.com...
I'm about to revive my darkroom, which has been sitting
gathering dust now for a couple years. (That dust is gonna
be a big problem, I know.) So I'm wondering if the place I
have in mind for it is dark enough.

It's the bottom half of my live/work space which has no
windows, at the opposite end of the room which opens into
the upstairs. I sat down there for a while tonight to see
how dark it was; after a few minutes, I could just barely
make out faint lightness at the other end of the room, but
could see nothing definite.

So I'm wondering if there's a rule of thumb about how dark
is dark enough. You know, something like the "sunny 16"
rule about what can be seen with the naked eye.

Yeah, yeah, I know I could make some test exposures with
paper, but you know what? I just don't want to. I'm not
planning on making any gallery-quality prints, just want
to print the last couple of rolls of film that I shot. So
if you have any rough guidelines, I'm all ears.

My impression is that it's plenty dark enough, so long as
I work fairly efficiently and don't leave paper exposed to
ambient light for too long.

Its an impossible question to answer without testing.
As a rule of thumb if you can see _any_ light once your eyes
become dark-adapted, its too much. It takes a minimum of
half an hour of darkness for eyes to reach maximum
senstivity. Often a room which appears to be completely dark
at first will prove to be surprizingly bright once your eyes
get used to it.
Since the sensitivity of film or paper is boosted by
exposure to low-level light even small amounts can cause
slight fogging.

--
Richard Knoppow
Los Angeles, CA, USA