Digital BW, The Print

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From: "Mark Tucker" <mark@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Saturday, October 19, 2002 3:59 PM
Subject: [Digital BW] Re: Reflective Densitometer Method


> --- In DigitalBlackandWhiteThePrint@y..., "Martin Wesley"
> <mwesley250@e...> wrote:
> So this seems like a good deal.
> > Quite a bit of X-Rite equipment on eBay at similar cost
> reductions if you
> > are interested.
>
>
> I remember going down that path years ago, when getting
> obsessed with those Ansel Adams and Fred Picker books. I
> bought my densitometer and starting doing overly-picky tests
> measuring base fog, etc, and determining my working ASA, etc.
>
> I tested and tested, then I'd get in a real job, shooting a real
> photograph, and the conditions would just never be right. I'd get
> all flustered, and just say Screw It, and just take a meter reading
> like I always did.
>
> Part of me wants to caution you about getting to hung up about
> all this tech stuff. Once you go down that road, something
> changes, or at least it did for me. But then again, I then
> remember that old Ansel Adams quote, (what was it?).
> Something like "Luck favors the prepared mind", and then I say,
> OK go ahead and buy your densitometer. Just don't get too hung
> up about it. I picture Winogrand or RobertFrank doing that, and I
> just laugh. Especially Winogrand.
>
> Sorry for the ramble. All hopped up on Frappachino Mocha this
> afternoon...

Mark,

Ymmm. Sounds good.

Actually I have already been down the densitometry road about 10+ years ago.
I was lucky enough to have access to a MacBeth color Transmission/Reflection
densitometer at a local Camera store (Bear Images in Palo Alto, CA. Great
folks.) and never had to shell out the several thousand dollars it cost. I
did a great deal of film and developer testing as well as papers and toning.
Wound up coming up with my own pyro film developer system where the ability
to measure blue density really helped. Followed the whole AA thing. In the
end I think it was time well spent, in that it gave me a much better
understanding of the whole process, scene to print. Made me think about my
exposures more carefully.

However, after a certain point, on the scene judgment becomes as important
and you have to go,  "Well I have been in a similar lighting situation
before and this will probably need a bit more exposure and a tad less
development than my testing indicates." or whatever. I think the biggest
problem for a true Zone approach to landscape photography is that even with
the best spot meters you are easily going to be off 1/3 or 1/2 stop in your
zone placements.

So I worked out my film speeds and my developments by the book, then as I
have shot over the years I have tweaked the speeds and developments to give
me negatives I liked better than what I could get by strictly following the
system. If I am shooting from a tripod with roll film, I always bracket even
though it is very rare for me to use the "+" or "-" exposures. Film is
cheap. If I am shooting sheet film I almost always expose two sheets, one
for the development I think the scene requires and one for development above
or below. I haven't measured film with a densitometer in a long time.

Mostly I got the 811 for inkjet print densities since my Spectrocam is not
accurate at densities above about 1.7. I have been shooting a bit of Ilford
SFX lately and I might do some Zone density checks but I'll probably never
get around to it. I would have killed to have an instrument like this ten
years back though. <G>

Martin

From: "Antonis Ricos" <antonisphoto@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Saturday, October 19, 2002 4:12 PM
Subject: [Digital BW] Re: Reflective Densitometer Method


>
> > Any precanned software to let you access the serial output on these
units?
>
> Have you checked with X-Rite? They may have a "utility" of sorts.
>
Antonis,

I wondered around there and I didn't find anything. Info on what pin on the
serial connection does what so you can write your own I guess but that is
probably not worth the effort in my case.

Martin

From: "Martin Wesley" <mwesley250@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Sunday, October 20, 2002 12:33 AM
Subject: Re: [Digital BW] Re: Reflective Densitometer Method


> Lloyd, Jeff, Paul, Antonis,
>
> Thank you for the feed back. I guess there is no standard for how to back
> semi-opaque samples for reading reflectance. Since almost all of our work
in
> this regard is to compare one process to another or "before & after"
> situations all that matters is that we be consistent as you say. When we
> post results we should note how the measurements were done, at least for
> paper white and the lighter tones which are the most effected.
>
> The white underneath to match mounted prints makes sense in one way but
not
> another. I speculate that the increase seen from light passing through the
> paper and being reflected back out is a result of a very intense light
> source for taking the reflected density light readings that may far exceed
> any normal level of illumination for print viewing. So using a black
backing
> for density readings might actually give a more accurate reading for
prints
> that will wind up mounted. Don't know for sure.
>
> I get the same result as Antonis, that is I get the same reading with no
> backing as I do with black backing. So I think that I will go with black
or
> no backing for my own measurements since this will be consistent to with
my
> Spectrocam which uses a black measuring plate.
>
> On the color readings the 811 has Tm for C-41 processed film, (I gather
that
> the instrument has circuits or programming to filter out the orange mask),
> Ta for E-6 processed slide film and R for prints. To answer Austin's
> question, the 810 and the 811 are identical except for the addition of the
> E-6 profile in the 811. These were designed for process monitoring for
> commercial film processing businesses. In each of the three modes you can
> measure in "VIS" or "RGB". A bit annoying that you can't get all 4 to
> display at once.
>
> Any precanned software to let you access the serial output on these units?
>
> Now that I know that R density = -C density I am wondering how you would
> calculate CMYK% and Lab values from the RGB density numbers.
>
> Did get new calibration plaques by the way and I was able to down load the
> manual from X-Rite. Just basic operational info though.
>
> For those interested I picked up the 811 on eBay for $325 including
shipping
> plus another $125 for new calibration plaques for a total of $450. The 811
> sells new for $4,250 and the 810 for $3,500. So this seems like a good
deal.
> Quite a bit of X-Rite equipment on eBay at similar cost reductions if you
> are interested.
>
> Thanks,
> Martin Wesley
>
> http://www.borderless-photos.de/guests.html

The consensus on the colorsync list was to add extra sheets of the same
paper you measure. The black at the back was only advised when there's
another print or text at the other side of the paper like it happens in the
printing industry. 'The same paper' as that will not influence the
measurements for colour readings like another white paper will do. The
amount of light doesn't influence the reflectancy, paper fibres will deflect
the rays enough to give a uniform reflectency percentage from any source.

Ernst