which 48 bit BTW is completely useless and meaningless
for b&w, which is only 8 bit...12 max.

I apologize for the multiple replies. Just wasn't
thorough enough. The claim of a 4.2 D-max is likely
based on the claim of the bit depth. Truth/reality
is, the Dmax is _pragmatically_ always based on the
signal to noise ratio of the scanner, not the bit depth.
And as I say, no CCD flat bed can achieve a 4.2 Dmax
and no inexpensive flat bed can process 48 bits.

Thank you for your reply...  I thought the scanner sounded a little too
good to be true.  On the ebay thing...  I could actually afford that -
I'm just a little weary of buying something used on ebay that I don't
know a whole lot about/never had experience with.  What brands are
good, which ones stink.  What features I really need.  Those types of
things.  Can you (or anyone here) give me some pointers on what to look
for or watch out for?  I don't need anything super professional, just
something that works and will be accurate enough for a beggining zone
system student to use on film and prints.

O.K.well I should probably clarify what I said.
I meant no such thing as a _cheap_ 48 bit scanner,
since if the scanner is cheap they likely had to
sacrifice some higher end components _somewhere_
(meaning even if it can scan a true 16 bits per
channel likely can't process/deliver 48 bits.)

In any case, looks like the i900 incorporates
a separate scan bed for film, which is good --
better than using an adapter for scanning film
on the flatbed. But I'm skeptical of the claim it
captures "more tonal information than a stand alone
film scanner." I.e., they don't actually say *which*
stand alones (low end/high end film scanners) it's
"better" than.

While the Dmax claim is clearly bogus, it's probably
fine for scanning negative film (negative films have
a low Dmax anyway, 2.8 or less.) Possibly fair for
transparencies but not high end (4.0 Dmax.) Again,
no way to know without testing. Problem is
manufacturers don't provide a true Dmax based on
s/n ratio since if they did they couldn't make
extraordinary claims about their products...

 Mr. Savage should take note. Although I've a fine Tobias
densitometer for under $80 from eBay I also have the under
$30 Ilford EM-10 enlarger meter. That and the step tablet
used for calibrating the EM-10 will allow for density
determinations.
 Search this NG for, densitometer EM-10 .             Dan

OK, as most of you know, I am not a true "Zonie" but I use some of the
techniques but without the rituals.

First:  the whole true film speed thing can be thrown out the window,
instead choose a "comfortable" EI instead, note that my film choice outside
is TX, TXP in the studio, I usually rate both at 200 and meter with a Gossen
Luna Pro F.  When I shoot flash in the studio I adjust my lighting to get a
contrast range that I know will reproduce on my normal paper.  When I shoot
available light I either use the Luna Pro in incident mode which is
essentially metering for N in Zone terminology, or since TX compresses
highlights nicely, I meter for adequate shadow detail and don't sweat the
highlight placement.  For the last 100-150 years that's been called "expose
for the shadows and process for the highlights".

Expansion and contraction are done with VC filters since you can't process
individual roll film frames, I understand that Ansel Adams used multiple
Hasselblad backs so that he could do expansion and contraction with rolls of
film.  I have heard of a guy using a 35mm Exacta (which had a film cutter
built in) and would adjust processing for each series of shots.

You could shoot a Zone series, something like this:

expose a gray card with a black X and a white X, meter for Zone 5, shoot a
frame, close down four stops, shoot a frame Zone 1 (5-4), open up one stop,
Zone 2 (5-3), etc.  when you're done process for the manufacturers
recommended time.

adjust the exposure of your contact sheet so that "Zone 5" looks the same as
medium gray, two negatives over would be "Zone 3" and "Zone 7", "Zone 3" the
gray card should be pretty black but you should still be able to see the
black X on the contact sheet.  On the contact frame for "Zone 7" negative
the gray card will be pretty light but you should still be able to see the
white X.  One refinement, check that you are printing for maximum black, the
film edges (which receive no exposure) should print to max paper black--if
you have to print lighter than this to get a medium gray from your "Zone 5"
negative you are not giving your film enough exposure.  If your "Zone 3" and
"Zone 7" negatives have no detail when printed you need to reduce your
development time if your "Zone 2" and "Zone 8" contact prints look like my
description of what 3 and 7 should look like you need to increase you
processing time.  I would not vary my processing time by more than +/- 15%
for a second test if needed.  It probably will be needed.

So you're down to one last thing:  metering, when I use a spot meter or my
Luna  (the F and SBC use a readily available 9v., not a PX-625, and have a
factory Zone scale), I will normally use one of the following:

1)place shadows with detail on Zone 3 and let other values fall where they
may

2)check my highlights and adjust exposure to keep highlights no higher than
Zone 8 (I can push them up the scale in the darkroom),

3)or use my incident metering mode for an average exposure and check the
placements as required depending on how much time I have.

BTW film densitometers are cheap, I picked up a little X-rite at an auction
for $5.00 (graphic arts but hey it measures density as well as DOT) and was
given a Sergeant Welch Densichron.

I have one :)

Worth adding to a book collection and an interesting
read.

Ha!  I love it!

Being a completely new amateur at this LF thing, and wanting to
experiment a bit, I read a couple of books (well ok, I scanned thru'
them :-) ) about the zone system, and summarised what I had read as
being exactly what is presented above or, as I interpreted.........::
1) meter the range of brightness in the scene
2) expose for detail in the dark areas
3) develop with compensation for the overexposure in the bright areas

Ok -  it's a bit simple, but then so is my knowledge and ability so far.
This has worked well for me any time I have managed to be disciplined
enough to apply it.

just my newbie $0.02 worth

cheers

Why should you avoid them? If you mess up the mid-tones to do it, the
image sucks anyway!

I already have digital, and I use it a lot too...  however, I find film
more engaging/challenging/rewarding.  I use both, but right now I'm on
a film kick. :)