Dilute HC110 1:30 from Stock Question

[IanBarber]

Ive just been reading "The Negative" by Ansel Adams and on the compensation chapter, he says that he diluted HC110 at 1:30 from stock and developed for 18-20 minutes.

When he refers to stock, is he talking about how it arrives in the bottle i.e syrup?

I always get confused with the word stock

[Kevin Crisp]

There is another recent thread on this. "Stock" HC110 is a dilution. So he can't be talking about the yellow (back then it was brown) syrup. 1:30 from syrup would be essentially normal strength, since 1:31 gives you 32 oz of Dil. B.

[IanBarber]

There is another recent thread on this. "Stock" HC110 is a dilution. So he can't be talking about the yellow (back then it was brown) syrup. 1:30 from syrup would be essentially normal strength, since 1:31 gives you 32 oz of Dil. B.

This is what I was thinking. Thanks, i will try and track down the other thread

[Ken Lee]

It would be a lot easier if instructions read 1 + 31

[Kevin Crisp]

In case you are not familiar with this resource: http://www.covingtoninnovations.com/hc110/index.html

[Jerry Bodine]

Ian, look at the first paragraph in this (https://web.archive.org/web/20150214232847/http://www.kodak.com/global/en/professional/support/techPubs/j24/j24.pdf) Kodak link to HC-110, where it defines the stock solution as the concentrate diluted with 3 parts water (1:3); the working solution for Dil B is then made by further diluting the stock solution with 7 parts water. This is equivalent to diluting the concentrate with 31 parts water (1:31). Looking more thoroughly at The Negative, AA uses the same terminology as Kodak, stating on p.187: "I prefer to prepare the basic stock solution from the concentrate, (since it is difficult to be accurate), and I then dilute this stock solution 1:7 for normal development. I have used [the stock solution] 1:15 for contraction, and occasionally 1:30 or more for compensating effects ..." I have personally always diluted from concentrate, but it's important to make certain ALL the concentrate is rinsed well from the measuring device into the container used for preparation of the working solution, before adding the final amount of water. I think this procedure resolves the accuracy concern.

BTW, I queried Steve Anchell about the use of the colon vs. the (+) in specifying dilution; he said they mean the same thing, the colon is just an older way of saying it. I agree that the use of (+) leaves no confusion.

[Jerry Bodine]

...Thanks, i will try and track down the other thread

http://www.largeformatphotography.info/forum/showthread.php?136662-Please-Clarify-My-Poor-Maths-For-Developer-Dilutions&p=1374328#post1374328

[Greg]

I use a syringe with the stock syrup. I also increased the amount in the syringe by 10% to take in account left behind concentrate within the syringe. Initially was rinsing the syringe (measuring device) but got too messy and time consuming.

[Jerry Bodine]

I use a syringe with the stock syrup. I also increased the amount in the syringe by 10% to take in account left behind concentrate within the syringe. Initially was rinsing the syringe (measuring device) but got too messy and time consuming.

Greg, does your syringe not have a plunger that can be removed so that you can flush it with water (into the working solution container) before adding the final water to make the working solution? Just wondering how that is messy or time consuming. Would that not be more accurate than guessing at 10% or whatever.

[BetterSense]

When I use a syringe a just suck the diluted developer in and out of the syringe a few times. No need to disassemble the syringe.

I do appreciate how much easier Rodinal is to mix up compared to HC110, however, Rodinal is not as immortal as HC110.

[Vaughn]

When I use a syringe a just suck the diluted developer in and out of the syringe a few times. No need to disassemble the syringe...

I do a pretty good job of rinsing out the syrup from the graduated cylinder. The important thing is to do it the same way each time, such as BetterSense seems to be able to do with the syringe. Though for the average practioneer, I doubt they'll find it significant.

[IanBarber]

Ian, look at the first paragraph in this (https://web.archive.org/web/20150214232847/http://www.kodak.com/global/en/professional/support/techPubs/j24/j24.pdf) Kodak link to HC-110, where it defines the stock solution as the concentrate diluted with 3 parts water (1:3); the working solution for Dil B is then made by further diluting the stock solution with 7 parts water. This is equivalent to diluting the concentrate with 31 parts water (1:31). Looking more thoroughly at The Negative, AA uses the same terminology as Kodak, stating on p.187: "I prefer to prepare the basic stock solution from the concentrate, (since it is difficult to be accurate), and I then dilute this stock solution 1:7 for normal development. I have used [the stock solution] 1:15 for contraction, and occasionally 1:30 or more for compensating effects ..." I have personally always diluted from concentrate, but it's important to make certain ALL the concentrate is rinsed well from the measuring device into the container used for preparation of the working solution, before adding the final amount of water. I think this procedure resolves the accuracy concern.

BTW, I queried Steve Anchell about the use of the colon vs. the (+) in specifying dilution; he said they mean the same thing, the colon is just an older way of saying it. I agree that the use of (+) leaves no confusion.

Thanks Jerry

This has more or less answered my question now.

To arrive at AA 1+30 for compensating, I think according to my math, 1+119 direct from the syrup would be pretty close

[Jerry Bodine]

...To arrive at AA 1+30 for compensating, I think according to my math, 1+119 direct from the syrup would be pretty close

Ian, you are pretty close. There are additional factors to consider. One is testing to find the least agitation/technique that avoids mottle/uneven development. Another is to make sure the negative(s) are kept submerged and separated to avoid floating to the top during the lengthy period between agitations, noting also that the larger volume of developer will necessitate a larger tray than usual. AA suggested putting the negative(s) in hanger(s) and provided a starting point for the agitation, based on his own preliminary experiments. He recommended working with just one negative at a time. My agitation was done by keeping the hanger submerged and SLOWLY raising/lowering the hanger once at each interval. I followed his suggested agitation intervals – with some slight variations - in doing my own testing. I also found a one-stop loss of effective film speed (EI) due to the reduced agitation by exposing two sheets (one with and one without a step wedge) in camera. The non-wedge film was used to check for mottle. I put them in a four-up hanger. I submerged the hanger in water in an 11x14 tray (prior to testing) to see how much working solution would be needed to allow for agitation. I found the best agitation to be constant for the first minute, then 15 sec every 5 minutes, for a total dev time of 20 minutes.

Note AA's comment (p.228): "Remember also that a definite amount of developer energy is required for a given film area. You must therefore be sure that the highly diluted solution contains the quantity of developer stock solution used for normal development based on the number of ... square inches of sheet film." To determine how much stock solution per given film area needs to be in the working solution to prevent the solution from becoming exhausted (keeping in mind Kodak’s statement in the first paragraph that stock solution is made by diluting the concentrate 1 part + 3 parts water), look at Kodak's HC-110 link for the working solution's capacity requirement on p.7 (values are given for both U.S. and metric systems). This link (http://www.onlineconversion.com/) is useful for converting to metric. Maybe it will help if I lead you through my calcs.

CAPACITY CALCS:
For normal development, one gallon (128 oz) of Dil B (1+7) will develop 10 8x10 sheets (that's 80 sq.in. of film x 10 = 800 sq.in.). 128 oz divided by 800 sq.in. = .16 oz per sq.in. [4.7 ml per sq.in.]. So the working solution, at ANY dilution, for a single 4x5 negative (20 sq.in.) must contain at least .16x20 = 3.2 oz [95 ml] of Dil B developer. This represents the stock solution that is diluted 1+30.

DILUTION CALCS:

Kodak’s link p.2 shows a table for preparing working solution from stock solution. It only illustrates dilutions up to 1+19, but it’s clear that, for any desired dilution, the volume of stock solution is multiplied by 30 to get the volume of water to be added to 95 ml stock to arrive at the working solution volume. The volume of water is 95x30=2850 ml, then added to the 95 ml stock is 2850+95=2945 ml working solution. If you’re like me and prefer to always prepare working solution volumes directly from concentrate, then you would recall that the stock contains 1 part concentrate + 3 parts water, a total of 4 parts. So the concentrate is ¼ of the stock volume, which means that 95/4=23.75 ml concentrate is “topped up” to make 2945 ml working solution.
The dilution of concentrate would then be (2945-23.75) water volume divided by 23.75 concentrate = 1+123. So, you’re not far off, Ian.

Btw, I found that I needed 3100 ml working solution to allow for my agitation technique, so for one 4x5 sheet I would have modified the concentrate volume to 25.6 ml. Thus, 25.6x4=102.4 stock; 102.4x30=3072 diluting water; 3072+102.4=3174 working solution; concentrate dilution is 3174/25.6= 1+124.

[IanBarber]

Thanks Jerry, you have supplied quite a bit of information for me to study