[Leica] Delta 3200

["Johnny Deadman" <deadman@jukebox.demon.co.uk>]

So, I'm sorry some LUGers took offence at my street shooting technique...if
you had been there you would have realised it was not a 'viscious' invasion
of privacy at all, and that I am a very inoffensive presence. Also, anyone
who wishes to 'f***ing' thump me is always welcome to do so, and should
email me privately to arrange a time.

There are some tense people on this list, aren't there?

Anyway, moving on, something else interesting emerged from that afternoon's
shooting. I shot (for the first time) on Delta 3200 after several people, on
this group and elsewhere, sang this film's praises.

Unfortunately, the negatives I took out of the can were uniformly two stops
underexposed. This worried me and didn't seem to make sense, so over the
weekend I ran a series of tests on D3200 in various developers, at various
dilutions (details below), and ultimately put it up against Tri-X to see
what the hell was going on.

In the end, I should have realised, the answer was kind of in the question.
Delta 3200 is a 'push' film. My tests revealed what is hidden in the data
sheet... its actual speed is around 1000ASA. This means that, pushed to
3200, Zone III and IV  just fall off the map, though highlights and midtones
may be okay due to the increased contrast from push processing.

In other words, for situations where you absolutely need 3200, it may be a
good choice to push, rather than Tri-X or whatever, but you *cannot*
substitute it @ 3200 for your regular film and expect good results.

I felt pretty stupid when I realised this, but then I forgave myself. After
all, it says 3200 on the box, right?

Even at 1000 (my number was 800), the extra stop comes at a very large cost.
The acutance and edge contrast is nowhere near that of Tri-X.

The only thing I did not test was its performance in Microphen. Some users
report a slight real increase in speed in this developer. However, I had
given up the will to live by this point.

The last time I posted some darkroom info a number of people emailed
privately to say they found it interesting, so here are my test results and
methodology for anyone who's interested (from a post to rec.photo.darkroom).
Apart from anyone else, for those who've never tried it, they show one way
of going about a diagnosis of an apparently inexplicable development
problem.

I would welcome observations and comments.


- ----- BEGIN TEST -----

I shot my back garden in flat light. My T90 in all modes confirmed my
Sekonic incident meter that at an EI of 3200, the exposure at 1/250 was f11.
(The spot reading of a grey card suggested 500 @ f11, but there was a lot of
deep shade in the scene which I wanted to retain some kind of texture, if
not detail).

Zone III was a garden shed door. Metered with the T90 spot it fell dead on.
This was going to be the litmus test for the 'real' speed...the first neg in
which this retained full texture would tell me what I needed to know.

I shot this at 800,1600,3200, 6400 and 12800 several times, then cut the neg
up and loaded each test onto a separate reel.

The first strip was developed in fresh D23 for 10' @ 75F (I just made this
solution up and was having difficulty cooling it down). This is, if
anything, slightly more generous than the 12' @ 68F I gave the film
yesterday.

The result: exactly the same. The first and only exposure in which Zone III
had full texture was 800 ASA. The rest were not even close. At 1600 the door
was textbook Zone II. At 3200 it disappeared.

Okay, so now I'm thinking... maybe D23 just isn't the developer for this
film. So I now develop the second strip, identical to the first, in D76
under *exactly* the conditions specified on the Ilford data sheet downloaded
today from the web. Namely, 10'30" @ 68F. (Agitation in both cases is
5s/30s). (NB -- This developer is very close to what Ilford say they derive
their film speeds on, ID11)

Result: almost exactly the same.

The D76 negs have a sliver more density, but that is all. Maybe a third of a
stop, tops. If I was being generous I would say 1000 ASA. The 800 ASA
exposure is still, absolutely, definitely, the first in which you can see
full texture in Zone III. The highlight density is somewhat greater as you
would expect, but that is not what we are testing for.

Okay, so now I am getting almost creeped out. John "Spectrum" has posted a
pic on his web page, very nice too, which is D3200 pushed to 6400 in D23. So
I decide to do exactly the same with my remaining strip.

But -- and this is where it gets interesting -- I decide that I am going to
introduce a control. I mean, maybe I meter in a really odd way. Maybe my 800
is everyone else's 3200. Who knows?

So I expose a strip of TX on the same scene (the light remained exactly the
same - I remetered throughout) at my normal working EI, 320 - and then at
every EI from 100 asa right up to 6400 asa.

Then, I developed *exactly* as John "Spectrum" suggested. Namely, 35' in D23
1+3 at 70F, with agitation 10s/60s.

Now, you see, not only have I got the D3200, but I have tri-x developed
exactly the same way. We may not agree about D3200 but we are sure as hell
going to agree about Tri-x. They have both been pushed the same amount in
the developer, they have been exposed in exactly the same way, in the same
camera. So -- whaddya think? Did the D3200 make 6400? How did it compare to
Tri-X?

I have the negs in front of me on a light box with a high mag (Konica) lupe.

In terms of shadow detail, the D3200 negs are *identical* to the D3200 negs
which I developed in D76. They have a tad, maybe a third of a stop, more
density. The first negative which shows detail in Zone III is the one I
exposed at... 800 ASA.

Okay, what about the Tri-X? I now place the strip against the D3200.
Remember that the TX is exposed at all EIs from 100 --> 6400 and developed
in the same can.

We are looking for first full texture in Zone III, right?

400 ASA. Clear as a bell. I am not going mad after all. Clearly the extended
development has pushed the contrast, but you can't cheat Zone III. There it
is. 800 ASA -- not there. 400 ASA. There.

I can draw absolutely no other conclusion than this: For me, Delta 3200 is
an 800 ASA film, or 1000 with a following wind. That's it. And that's why my
negs were underexposed yesterday.

Actually, that's not quite it.

There is a sign at the bottom of my garden with some small writing on it.

You can read it on the Tri-X neg clearly. It is illegible on the D3200 neg,
whose acutance and edge contrast is much lower.

So what's going on here? In the end, the answer came from Ilford's data
sheet for D3200 which I went back to in case I missed something. Oh, boy, I
missed something. Here it is, on page 1. It says ... and I quote ...

"Delta 3200 has an ISO speed rating of ISO 1000/31º (1000ASA, 31 DIN) to
daylight... It should be noted that the exposure index (EI) range
recommended for Delta 3200 Professional is based on a practical evaluation
of film speed and is not based on foot speed, as is the ISO standard".

Doh!


- ---- END TEST -----



- -- Johnny Deadman

"Write without pay until somebody offers pay. If nobody offers within three
years, the candidate may look upon this circumstance with the most implicit
confidence that sawing wood is what he was intended for" - Mark Twain