View Full Version : combi plan tanks

colin smith
17-Mar-2004, 12:32
just processed my first sheet films in a combi plan tank. it must have taken me the best part of 5 mins to get all the developer in, and the same to get it out (and with stop and fix). is this normal ?

this tank was recommended as a great option, though if the above is normal, then doesn't it blow holes in the intricacies of the zone system ?

should i have developed my negs in trays and saved myself unnecessary expense ?

thanks in anticipation

Larry Gebhardt
17-Mar-2004, 12:44
To fill the tank you must turn the top valve a full turn to open the air vent. This will let the fluid push the air out of the tank. When full you then close the valve. This should reduce your fill time to about 25 seconds. Practice with no film in the tank.

Gem Singer
17-Mar-2004, 12:55
Hi Colin,

Take a look at the article I wrote for the Large Format Photography Home Page on this website. Scroll down to Processing and Printing, then click on "Developing 4X5 Sheet Film an Alternative Method".

If you are going to only use one tank, it's a good idea to fill the tank with developer, load the film on the rack (in total darkness), then dip the rack (containing the film) into the developer, place the top on the tank, and then turn on the lights. Begin pouring the developer out about thirty seconds before the end of the development cycle. Pour in the stop bath (with the lights on). When the stop bath cycle ends, pour out the stop bath and pour in the fixer.

I like being able to use the Combi Plan tank as a film washer, leaving the films on the rack until they are ready to hang and dry (see the picture included with my article).

Leonard Evens
17-Mar-2004, 13:25
I have a Combi tank, but I use it just as a film washer. Instead I use a Beseler drum on a motor base. Many others use Unicolor tanks similarly. Unicolor and Beseler drums may be found regularly at ebay. This method lets you develop up to 4 sheets of 4 x 5 film using as little as 6 ounces of solution. You will find a discussion of how to go about it elsewhere on this website.

17-Mar-2004, 14:32
It should take 25-30 seconds to fill the tank with the valve open. Practice in the light until you have the system down.

John Cook
17-Mar-2004, 14:45
I also recommend Eugene's article. Highly. I have been using his method almost every day (commercially) since 1967. Never had the slightest problem. I've also done exactly the same thing with roll and 35mm film in a row of dedicated stainless tanks. "Daylight" tank developing is frought with contamination and agitation problems. It's really not very good technique.

Bob Salomon
17-Mar-2004, 16:14
Did you buy a new or used tank? If new did it have the instructions in the box? Do you need a copy of the instructions?

17-Mar-2004, 18:44
Colin, beware of photographers promoting the one "good" or "true" technique. Speaking for myself, I have never had a contamination or agitation problem with the Combi-Plan. Try what works for you consistently, and avoid the fundamentalists.

Gem Singer
17-Mar-2004, 21:15

I totally agree with your statement. However, Colin posted his question because he has not yet been able to obtain consistent results with the Combi Plan tank. John Cook and I are attempting to help him, not belittle his efforts.

I, for one, am far from being a fundamentalist. After many years of struggling, I switched from tray development to Combi Plan tank development, because I found that it was very difficult to obtain the consistent results I was seeking, using tray development. Please read my article.

Nobody mentioned a "good", or "true" technique. We all realize that there is no such thing, when it comes to photography

colin smith
18-Mar-2004, 12:21
thank you all. i did open the valve but only half a turn. Thanks bob, but i do have the instructions. But as ever, operating in splendid isolation with only an instuction leaflet is often not the ideal. It does illustrate however what an invaluable resource this site is. Eugene i look forward to reading your article, thank you. All that remains is a bit of practise ! colin

Leonard Metcalf
19-Mar-2004, 18:19
I was quite scared of consistent results with the combi, and tried to learn tray processing - scratched some nice shots, ended up processing one at a time- then read Barry Thornton's notes which helped alot (described in his first book) and now have a repetable procedure.

Now I am getting good & consistent results...

I fill from the top and drain from the top. This way each bit of film gets roughly the same developing time. I also have found that it takes 25/30 seconds to fill and drain. Open the bottom dran to let air in as you empty. I pre soak the film too. I start the timer at the moment I start filling.

I also put two sheets of film in each slot (back to back - emulsion out) - then re fix a second time to clear the back of the films. This way I get 12 shots per run.

I did tests to work out a time, and as long as I am consistent with my procedure the films come out the same every time.

Charlie Skelton
22-Mar-2004, 03:19
I use a combi tank, 2 things may help. Use a bigger funnel than the one supplied. I use dilute development, with dev. times of typically 20 mins + an uncertainty of 30 sec becomes marginal.


22-Aug-2013, 00:08
Thanks Bob, but i do have the instructions.

Bob says HP Marketing no longer has copies of the instructions available. Colin, could you scan the instructions and put them up here for everyone to have access to? That would be great, thanks.