Archived posting to the Leica Users Group, 2005/03/24

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Subject: [Leica] bill dilution H.
From: saganicc at (Saganich, Christopher/Medical Physics)
Date: Thu Mar 24 15:55:45 2005

Thanks Bill,

I tested some triX last year in dilution H. I found ASA 160 to be optimal 
for this dilution if you want good shadow detail, but ASA 320 was only a 
stop difference. I never finished the testing but I am about to start using 
Trix and HP5 soon, this weekend.  

Currently I'm only using FP4 ASA 100 in HC110, 1:42 dilution which is close 
to Dilution D, (I just started mixing 12ml per 500ml for convenience).  I 
generally run at 70F for 9.5 minutes light agitation, 5 seconds per minute.  
I can get a good density range for grade 2 and 3 paper with this 
combination.  I made a lot of tests based on Dan Ridings suggested that 
development time and dilution might be linear.  

Looking over my FP4 testing today after your reply I see 2 good data points 
to test Dan's suggestion.  A 1:33 dilution at 4.75 minutes and a 1:42 
dilution for 7.5 minutes gave me the same density range for FP4 (1.21 
between zone I and VIII.)  Projecting a straight line down to 1:67 (dilution 
H) gives roughly a time of 12.25 minutes.  So if dilution and development 
time is linear I should get the same density from FP4 dilution H (7.5 ml 
concentrate) at 12.25 minutes.  

The linear graph is interesting, (yes I just made a graph), because it 
approximates a slope of -1 which suggests that that Time + ml of concentrate 
must approximate the intercept for that density range.  This suggests that 
with one good data point one could project the dilution and development time 
for any contrast range assuming the slope doesn't vary too much at the 

For Example:  For FP4 I run 9.5 minutes using 12ml concentrate for a density 
range of 1.26 between Zone I and VIII.  With an assumed slope of negative 1 
the intercept is 21.5.  So any combination as long as it is close to 21.5 
should give me similar contrast range.  So if I want to use a dilution of 
7.5 ml concentrate the time would be 14 minutes.  For Dilution B at 15ml the 
time would be 6.5 minutes for the same density range. 

If you eyeball the increase in contrast range between 12.25 
minutes(range=1.14 between zones I-VIII) minutes and 14 minutes (range of 
1.26 between Zone I and VIII) it is about one stop or one zone shift to the 
left.  Just about right.  This is great is it holds experimentally.

Bill you may be my muse I'm glade you asked!

 (212) 639-7391

-----Original Message-----
[] On Behalf Of bill 
Sent: Thursday, March 24, 2005 3:59 PM
To: Leica Users Group
Subject: Re: [Leica] bill dilution H.

Hi Chris,

My approximate normal time for TriX at 800 is diultion H at 11 minutes, 75 
degrees.  I had an odd accident, though, in this processing. I did two rolls 
in one can, and a single roll of 120 from something else in another, and I 
accidentally unthinkingly mixed the HC110H at half strength, so Pedro, John 
and Bob were developed in HC110 at a dilution of one-quarter ounce syrup to 
1000cc. I wondered why they were so thin. But yet apparently not too thin (I 
have not printed them yet). Mark was developed separately later in a two 
reel can, and I had my oh-shit moment when was pouring the syrup and 
realized what I had done on the first two rolls. So I went ahead with the 11 
minute time; these negs look normal and fine.

So what does this tell me? I won't know until I print, but HC110 even wicked 
diluted seems to keep working. I won't try that again, though. Your 

bill h

----- Original Message ----- 
From: "Saganich, Christopher/Medical Physics" <>
To: "Leica Users Group" <>
Sent: Thursday, March 24, 2005 3:44 PM
Subject: RE: [Leica] bill H.

> Bill,
> What time, temp are you using for the dilution H?
> Christopher Saganich
> (212) 639-7391
> -----Original Message-----
> From: 
> [] On Behalf Of Peter 
> Dzwig
> Sent: Thursday, March 24, 2005 2:15 PM
> To: Leica Users Group
> Subject: Re: [Leica] Sound missing
> bill harting wrote:
>> Tuesdays a pickup jazz group plays at my local coffee shop --  a lot for
>> talent for the price of a cup of coffee. Here are this week's players.
>> M3 90/2.8 TriX HC110h most shot at f2.8 to f4
>> all opinions welcome
>> bill h
>> _______________________________________________
>> Leica Users Group.
>> See for more information
> Like all of them Bob. The expression on Pedro's face is great. The photo 
> of
> Mark, although blurred conveys a lot about him, his playing and his mood.
> Thanks for sharing.
> Peter Dzwig
> _______________________________________________
> Leica Users Group.
> See for more information
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