Developing tube design

[Shesh]

In an e-mail thread I had started on the day the APUG server went down regarding which developer to use with Efke PL100 (being new to LF), I received a few recommendations for Pyrocat HD since it uses Pyrocatechin (given my reservations against using pyrogallol, if I could help it).

Since I was in the process of reading the responses when the outage happened, I may not have imbibed the messages correctly. I had mentioned that I intended to tray develop and somebody (possibly Jorge) recommended to try developing tubes. I would like to go that route.

The negative size is 3x4 and I bought a schedule 40 tube (gray electrical tube) of 1.25" diameter with end caps and couplers. The BTZS book mentions a ratio of approximately 1:3 for cap:film container parts of the developing tubes and also recommends constant agitation during development by rolling the tubes in a water bath to maintain temperature and provide even development. My question is what if I use a 1:1 ratio and just use inversion as the agitation method and keep the tubes vertical instead of horizontal in a water bath. This way I can agitate for 30 seconds the first minute and 10 seconds every minute thereafter, instead of providing constant agitation. Is this methodology OK, especially with Pyrocat HD?
Thanks in advance.

 

[Francesco]

In the minimal agitation procedure I use the tube is filled with enough Pyrocat working solution to completely cover (and some) the negative while the tube is in an upright position. The initial "roll" of 1 minute is critical to even development. After which I roll the tubes in water for 15 seconds every 3 or 5 mins until the end of the cycle. As long as your tubes can satisfy these criteria then it will be fine.

 

[roy]

In the minimal agitation procedure I use the tube is filled with enough Pyrocat working solution to completely cover (and some) the negative while the tube is in an upright position.

Francis, is this the way they work or your particular method ? I have never used the tubes but shall try in the not too distant future. I thought they were used somewhat like the Jobo system where a much smaller quantity of chemicals was used. I do not find fault with what you say as your results speak for themselves and I am on a learning curve. I suppose, on reflection though, that with either minimal agitation or stand development, you have got to ensure that the film is adequately covered at all times. Certainly something to bear in mind whatever system I use.

 

[Francesco]

Roy, this is the way it should be using tubes and minimal, semi-stand or stand procedures. When I use gentle but continuous agitation (either manually spinning the tubes in water, like I do, or using a motorised rolling base) the amount of solution used is about the volume of the cap or thereabouts. Of course with gentle agitation the dilution is stronger.

 

[juan]

There are generally a couple of ways to use tubes - and they are quite different, so it's easy to lose track of who uses which method.

One method lays the tubes horizontally and agitates by turning the tubes - either by hand in a water bath (BTZS) or on some type of motor base. With this method a relatively small amount of developer is used.

The other general method (and there are variations) is what Francesco uses - the tubes are left vertical and they are filled with enough developer to completely cover the negative. With this method agitation is much less frequent, the developer is usually more dilute, and development times are usually longer.

(Then there's my method, which is the one, true, correct method of film development with tubes.)

It's a matter of what you want to achieve, and experimentation.
juan

 

[Shesh]

Out of curiosity, why don't you want to agitate by rotation?

It has more to do with familiarity than anything else - While developing 35mm and 6x6 sizes, I use the more common method of keeping the whole negative spool dunked in the developer at all times (except while doing the inversion agitation).

I would guess that it is more difficult to achieve consistency while constantly rolling all the tubes manually, then by using the method that
Francesco describes above. If I make the size of the cap atleast equal to the part of the tube which will contain the film, then I should be able to ensure that 100% of the film is dunked when the tube is left standing vertical.

The only downside I can see at this point is the quantity of developer required. Which brings me to Pyrocat HD. Given that it is used at 1:1:100, would I be correct in assuming I need a larger quantity of the developer than I would if I were using say - FX 39 (which I use for 35mm and 6x6) or XTol?

 

[Francesco]

Shesh, one of the nice things about Pyrocat is how little of the actual stock solution is used as working solution. For example, when I develop 1 sheet of 8x10 I use only 12ml of stock Pyrocat HD (i.e. 12ml:12ml:1440ml - this covers the negative quite nicely indeed). If you are going to try minimal, stand or semi-stand agitation with your negatives measuring 3x4 then even less is required. I would not use 1:1:100 for minimal agitation - try 1:1:120 or 1:1:150.

 

[Shesh]

Folks,
Just wanted to thank you all for the recommendations. I completed making the developing tubes during the week and just got done developing my first LF negative using the tubes. I forgot to order Pyrocatechin in time and so developed this negative in FX-39 just as a "proof of concept" and it worked, no scratches from inserting/removing the negative from the tube, no light leaks from the end caps (I had to use Schedule 40 - white plumbing end caps and had to cover it with duct tape.), no fluid leaks, easy to use.
If anybody wants information about the pipes, just ask. Each tube (the part into which the film is inserted and the part which gets the developer) are of equal size. Each tube takes 120ml of developer.