Simple Agitation Question

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Hi,

Please help me by answering this simple question in regards to agitation when processing film.

A person processes two identical rolls of film using identical developers. For the first roll (A) he agitates slightly and every minute. For the second roll (B) he agitates vigoursly and at every 20 seconds. However he reduces the total developing time for (B) so that both the rolls have identical densities.

When comparing the negatives from A and B he will notice:-

1) That A has lower contrast than B.

2) That A has higher contrast than B.

3) Both A and B are identical in terms of contrast.

Please pick 1, 2 or 3! Thank you!!!

In case you are wondering why I am asking this question, the answer is that I am desperately trying to reduce the contrast Kodak Tech Pan. I just love the grain and sharpness of this film. But the contrast is just too much!

The developer I am using to process this film is Agfa's Rodinal mixed with a solution of water and sodium sulfite. I have tried all sorts of dilutions and 1:200 is the best so far. But still too contrasty...

Thanks!

-- Mike Foster (mike567@acgecorp.com), June 03, 2001

Answers

3 if time has been adjusted properly.

Note: Above based on films I've tested (not many). Phil Davies did report somewhere that dilution did not seem to change curve shape appreciably. Have you looked at other kinds of developers - POTA, D23 at 1:3, FX2 with A and B solutions in 1:2 ratio? Good luck, DJ.

-- N Dhananjay (ndhanu@umich.edu), June 03, 2001.


Well, while you're fiddling around, try Ethol TEC (follow label instructions for a starting point) and C-41 developer. Use the C-41 developer (developer only, not the entire process) for around 9'/68F giving ordinary intermittent inversion agitation of two inversions every 30 seconds, EI 16.

Also, you might try eliminating the sodium sulfite from the Rodinal working solution. Sodium sulfite is an accelerator, which you probably don't want.

Tech Pan is pretty contrasty stuff. I've tried a variety of developers with it; the curve shape is always basically the same, with pretty much the same CI, the primary difference being the D-Max obtained, or iow at what point highlights block up into detailless density. For TP that point is rather low.

-- John Hicks (jbh@magicnet.net), June 03, 2001.


Why not use Technidol?

-- Patric (jenspatric@mail.bip.net), June 03, 2001.

Mike, I used TechPan (135mm format) couple of months ago with good results. Shot at ISO speed 10 (ten). For any case I did bracketing for some frames +/- 1 stop. Developed in XTOL 1+5 (one plus five), 21 deg. Celsius. The agitation: first 180 sec -- vigorous, then repeatedly 40 sec no agitation, 60 sec -- moderate agitation. Negatives are normal, even slightly soft, quite printable, no excessive contrast. A note: the marking on the edges of the film (KODAK etc) is SLIGHTLY visible; it means that from point of view of intended use of this film (high contrast negatives) the film is severely underdeveloped. But for "pictorial" purposes it is ok.

Best wishes Andrey

-- Andrey Vorobyov (AndreyVorobyov@mail.ru), June 04, 2001.


I would say A AND reduce the developing time. I have shot ALOT of TP and you really have to be careful with this stuff and heavy agitation. You will find that you get chemical drag from the sprocket holes. Reducing the agitation will inherently reduce the contrast but if you want to reduce the highlight density, you will have to "pull" the film. If it is really bad, try reducing the developing time by 15% to start. Cheers

-- Scott Walton (scotlynn@shore.net), June 04, 2001.


I'm very sorry, in my post above I didn't tell the whole development time. It was 13 min. The bracketing was redundant, not compensated negatives are ok.

Andrey

-- Andrey Vorobyov (AndreyVorobyov@mail.ru), June 05, 2001.


I apologize for my error. My answer above refers to changes in dilution and not agitation - I should drink some coffee. In my experience, agitation does change the shape of the characteristic curve although this is probably qualified by film-developer interactions. Tech Pan (and document/lith films in general) are pretty much designed to deliver high contrast results and getting pictorial gradation, leave alone changing the shape of the curve can be extremely hard. I doubt changes in agitation alone will cure your ills. The typical pattern I've seen with agitation changes (as long as time is adjusted to compensate) is that reducing agitation can put a shoulder on the curve (this assumes, of course that time changes have been made to ensure that Zone whatever develops to the same density). The ease with which a shoulder can be produced seems a function of film-developer combination. For example, FP4 and D23 produces a shoulder very easily, FP4 and HC110 with more difficulty (i.e., greater reduction in agitation). With Tech Pan, I think producing a shoulder is going to be very hard because the emulsion was not designed to be a flexible one. So, I would still think that the answer would be 3 above. I would suggest trying a couple of other developers based on the recommendations above.

-- N Dhananjay (ndhanu@umich.edu), June 05, 2001.

Hi,

Thanks for all the replies. I tried rating it at 12 ASA and processing it in XTOL+4 and same darn contrast.

I think I will go back to Technidol. Nothing comes close to reducing the contrast and with Technidol I can shoot it at 25 ASA too.

So there!

Thanks again.

-- Mike Foster (mike567@acgecorp.com), June 06, 2001.


Mike, I've used Tech Pan @ ISO 50 in Photographer's Formulary TD-3 developer with very satisfying results. Mix as per instructions and use 100ml A + 100ml B + 800ml distilled water; develop for 14 minutes, agitating for one minute at the start (1 inversion/2 sec), then 10 sec/min, thereafter. If you find you want even less contrast, reduce the "B" solution to 50ml and develop for about 18 minutes.

Incidentally, this developer is based on catechol and so if you are unable to find TD-3 developer (you can order it directly from their website), you can make your own easily enough. I don't have my reference materials handy, but if you start with 5g catechol + 20g sodium sulfite in 1000ml for A, and 100g / 1000ml of potassium carbonate, you'll be pretty close to their formula. Catechol has wonderful compensating properties, and is ideal for Tech Pan. Ted Kaufman

-- Ted Kaufman (writercrmp@aol.com), June 07, 2001.


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