High Dilutions in Small Tanks

When using very diluted developers you have to make sure that you have at least

a minimum amount of concentrate in the tank. For instance, you need at least

10ml of Rodinal for one roll of film, or 6ml of HC-110, and so on.<br>

This can be a problem if your tank is too small. If you want to develop one roll

of film in Rodinal 1+100, you must have at least 1l of solution, which is more

than a small tank can hold. Rodinal 1+200 would be even worse.<br>

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So I was thinking: what if I divide the total amount of solution into smaller

parts and use them sequentially? Let's say my tank's capacity is 500ml and I

want to use Rodinal 1+100 for 30 minutes. I pour the first 500ml in the tank,

and after 15 minutes I empty the tank and pour in the other 500ml and continue

the development as usual. <br>

Do you think it will work? Has anybody tried this?

Get a bigger tank. Plastic tanks are not expensive and can be very handy to have around for those times when you want to use highly diluted developers.

Actually, I have tried this in my early darkroom days and it will work. However, it takes consistency which means one practices. It also is way more work than Frank's suggestion, :-)! One other method I have offered to others is get a large, graduated beaker/pitcher/container and make a large batch of your favorite ratio and pour the mixture from that into the small tank. Rodinal at 1:100 is dirt cheap and can be discarded if not used, or do a few rolls at a time. When doing my Minox rolls in the small tanks, I make a larger batch and do a few rolls in multiple tanks.

Indeed, use a larger volume tank. All other solutions are a bit crappy.

You can also cut your film in two ends, then you need the half amount of concentrate for half a film area but this is also a crappy solution.....

I have used Rodinal at 1:50 in an 8 oz. stainless steel tank. I make up 255ml of working solution by mixing 5ml of Rodinal into 250ml of water. So far I haven't run into a problem this way. Getting exact measurements at 1:100 or 1:200 or 1:300 for use with an 8 oz. tank can be too tricky. This is one reason some people use much larger tanks for stand develpment with one roll. Rodinal isn't really my favorite developer anyway and I am not convinced that stand development gives any meaningful benefit over standard development.

Like Jeff, I have had no problems with 5 ml or 6ml of Rodinal, at a 1:50 dilution (250 ml or 300 ml of total solution).

Howdy, I've been using Rodinal with APX 100. I rate the film 50 for sunlight and average contrast. I mix the Rod 100:1 with 600ml of water at 68. I use the Paterson two reel tank. I shake for the first min., then I invert once every 10 min for an overall time of about 40 min. I've been doing this for a couple of years, and it works for me.

Rodinal users have traditionally used precisely marked hypodermics or small (eg 1") diameter graduates for small amounts. Works fine.

Thank you all for your answers.<br>

David, that's precisely what I want to do. 1+100 with one inversion every ten minutes. I've read about this method, but have never tried it myself.

I have done this- separated the developer into two quantities to be sequentially used on the same film due to the dilution being too high for all the solution to fit in the container. I was doing it with sheet film in a Unicolor drum. Not fun, but doable if you are consistent. At high dilutions the few seconds of time during which you pour one out and pour the other in doesn't make that much difference.