Diluting Rodinal

[willscarlett]

<p>I have a question or two about diluting Rodinal. I'm familiar in general with how to make up the dilutions. I generally use a 500 mL tank with water and then add the necessary amount of concentrate to make a 1:25, 1:50, 1:100, etc dilution, but I've only ever developed one roll at a time when using Rodinal. Is it possible to develop two rolls of 35mm at the same time in a 500 mL tank, or would i need a tank that can handle four stainless steel rolls at a time, much like you need when developing two rolls of 35mm at the same time in D-76 1:1?<br>

<br />Also, for using Rodinal to develop 120 film in a 500 mL tank, can I mix things up the same way I do for 35mm - 500 mL water and 20 mL concentrate (1:25), 10 mL concentrate (1:50) or 5mL concentrate (1:100)? Or will I need more concentrate?<br>

<br />I think I remember reading somewhere that the minimum amount of Rodinal concentrate needed per roll is 10 mL, but you can get away with 5 mL if necessary.<br>

<br />Oh, and one last question. I'm taking large format this semester and we're developing using hangers. How do you dilute Rodinal for 4x5? Would it be worth finding one of those old stainless steel tanks for developing 4x5?</p>

[Fotohuis RoVo]

<p>Rodinal can be diluted from 1+10 (for photo PAPER) development to 1+25 - 1+200 (film development).<br>

The minimum concentrate for one 135-36 or 120 roll film (same area) is about 10 ml according Agfa specs but the real minimum is about 5-6ml per film. Under this minimum concentrate your success will depend on the amount black and white area in the negative hence you can not speak of reproducible results anymore.<br>

So 1+100 dilution: 5ml + 500 ml is able to develop one film.<br>

1+50 dilution 10ml + 500 ml is able to develop two 135-36 or two 120 roll films or one 220 roll film. A regular Jobo 1510 tank is 250ml, a 1520 Jobo tank 485 ml (500 ml) content so this is rather an easy calculation and practical point.<br>

For doing 4x5" sheet film you can use the 2509 sheet film reel. (6 sheets 4x5"). Inverse processing or rotating is both a possibility.<br>

For more content in the 1500 series you can use the 1530 extending module:<br>

1530 + 1510 = 1540 or use a 1520 tank + 1530 extension.<br>

The first combination is able to do 2x220 or 4x120 roll films (975ml content ( 1 Ltr.) ) for inverse processing and then it is also possible to do more films in a high dilution (1+100). The Jobo reel is equipped with a red clip to put two 120 roll films after each other without overlap crisis.<br>

Higher dilution = more sharpness but you need less agitation to compensate the growing grain. High speed films are less suitable in Rodinal due to the grain and higher dilutions means a too long developing time.<br>

Very high dilutions Rodinal are not working anymore over 30:00 minutes developing time.<br>

The advantage for stand processing in 35mm or roll film is neglectible so it's better to practice on slow agitation and a practical dilution from 1+25 till 1+100 in Rodinal indeed a very special Para-Amino Phenol developer.</p>

 

[derek_kennedy]

<p>RObert:</p>

<p>I can use Rodinal for paper as well?? When I read the label it indicated for film. It would be nice if I could use it for paper thought, cut down on the expenses a bit. 1:10? Amount of agitation? Is there a minimum of Rodinal I need to use when diluting for use on paper?</p>

<p>I'm waiting for my shipment of paper and chemicals (be a couple weeks or three still) - I have not actually used my enlarger yet.</p>

[frank.schifano]

<p>You won't save anything by using Rodinal for paper. Do the math. Robert's recommended dilution for paper strength Rodinal is 1+10. Figure you need at least 1L of total solution to have a decent enough amount to work with in a tray. That works out to roughly 90 ml. of Rodinal to 910 ml. of water. How much does a 500 ml. bottle of Rodinal cost these days? At B&H the price is around $16US, and they won't ship. That's enough for a bit over 5L of working solution at a price of about $3 / liter. To make matters worse, the developer is very short lived in the tray. After a couple of hours at most, it will be shot. </p>

<p>A dedicated paper developer like Dektol is much cheaper to use and will work better. Tray life is about 12 hours and a single liter of working strength Dektol will process at least 20 8x10's. If you don't exhaust it in one session, bottle it up and it will keep for another couple of days. $6.50 US will buy you enough powder to make a gallon of stock solution which is then diluted 1+2 or 1+3 to make a working solution. Cost per liter of working solution works out to about $0.60 for a 1+2 dilution and $0.43 at 1+3.</p>

[derek_kennedy]

<p>Thanks for that info Frank.</p>

<p>I was thinking of the Rodinal if I didnt have anything else handy. I did in fact order some Dektol but the shipment is delayed due to some of the paper I also ordered was not in stock so a delay of 1-3 weeks they figured.</p>

<p>Sigh.</p>

<p>Finally get a darkroom set up and I cant play with it :P</p>

[profhlynnjones]

<p>Hi John,</p>

<p>With Rodinal, as long as you have the film fully immersed, it will develop as advertized, there is always adequate developing agents for that purpose. If you wish to develop a second batch of film in the same solution, simply increase the developing time by 10 per cent. Dump it after that.</p>

<p>Regarding the dilutions, the principal reason is to get a convenient developing time. Some workers believe that higher dilutions will give finer grain or whatever, with my testing that is seldom the case, but possibly in a few instances.</p>

<p>Lynn</p>

[leicaglow]

<p>I routinely use Rodinal for stand development at 3.3 ml per liter. That's around half to a third of what is recommended as a minimum, but it always works for me. I've used it down to 2.5ml/l without problems as well.</p>

[willscarlett]

<p>Thanks for the replies, guys. So if I am developing something in a 1:300 dilution, I don't need to worry about keeping a minimum of 5 or 10 mL of concentrate per roll?</p>

[leicaglow]

<p>No; you don't. And actually, that 10 ml minimum is also listed as a 7 ml minimum. So it's suspect to begin with.</p>

[christer_almqvist2]

<p>Robert said: "Very high dilutions Rodinal are not working anymore over 30:00 minutes developing time.".<br>

<br>

I beg to disagree. I tested different development times for stand development using 5ml Rodinal per film (HP5+) with a dilution of 1+100. Each test included making ten shots of a grey card with zones from 1 to 10 and measuring the densities with a densiometer. Initial tests were with developing times of one and two hours. There were substantial differences between the high zone densities for these developing times, and none was what I wanted. A subsequent test showed 75 minutes to be about right, with the high zone densities being more or less in the middle of the two previous tests. </p>

<p>BTW, the ONLY advantage of stand development is that you need not invert the tank so many times.</p>

[willscarlett]

<p>So how many mL's of Rodinal concentrate might I need per sheet of 4x5 film?</p>

[User_502260]

<p>The exact amount of concentrate you will need will depend in part on what type of equipment you are using and what format. If you are developing 4X5 film in a deep tank and you intend to develop several sheets at a time or several sheets now and more later then you will have many more calculations to make. The Nikor type tank and reel set for 4X5 film will allow normal inversion just like you would use for roll film. If I had to use any kind of deep tank for 4X5 film I would rather use undiluted D-76 or undiluted Microphen with shorter times. The developer will then be exhausted much more slowly and there are several systems for calculating the time you add for each new sheet or set of sheets based on your volume. I don't know how many people are using Rodinal for 4X5 film<strong>.</strong><br>

A 36 exposure roll of 35mm film might have about 42,000 square mm of area while a 4X5 sheet will have about 12,500. Based on this you should be able to develop 3 sheets of 4X5 film with the same amount of concentrate which would be needed for a 36 exp. roll of 35mm film. If you prefer stand development and can calculate the correct dilution and time then using a deep tank will be fine because there will be no inversion. For more traditional developing and if you can get the hang of it, loading a Nikor reel with the sheets and using regular inversion for agitation is easier and a lot faster. The only disadvantage is that the old Nikor tank and reel sets can be expensive. If you intend to invert, don't buy one which s missing the cap.<br>

<strong> </strong></p>

[willscarlett]

<p>The last Nikor tank I saw on eBay went for $165. I just thought it would be cool to develop my 4x5 film in Rodinal since large format could easily handle the acutance of Rodinal, even at higher ISO's. But I may just stick with normal developer. We use the Sprint system at school, but I wonder how much is left since they went bankrupt.</p>

[User_502260]

<p>John-Paul, I'm sure I have some developer to spare if your school darkroom runs low. </p>

[willscarlett]

<p>Thanks, Jeff!</p>