CombiPlan and R5 Monobath in lit room, best practices.

[Lenrick]

I have those numbers, Bob, and I must confess that the differences are small enough to give you right concerning the time it takes to add the liquid. I'll probably compare the standard vertical method with Scheinfluger_77's hose method using R5 Monobath and Atomic-X. Since the Monobath is so unforgiving, any "flaws" in either method should be quite visible on the negatives.

The time it takes to fill the tank through the lid-port (the tank in standard vertical potion):
With air path in closed position: 1 min and 15 s
With the air path opened by half a turn: 27 s
With the air path opened by two turns: 27 s

The time it takes to fill the tank through the side-port (the tank laying in horizontal potion)
With air path in closed position (but no plug): 24 s

Are these numbers similar to your experience Bob?

[Bob Salomon]

I have those numbers, Bob, and I must confess that the differences are small enough to give you right concerning the time it takes to add the liquid. I'll probably compare the standard vertical method with Scheinfluger_77's hose method using R5 Monobath and Atomic-X. Since the Monobath is so unforgiving, any "flaws" in either method should be quite visible on the negatives.

The time it takes to fill the tank through the lid-port (the tank in standard vertical potion):
With air path in closed position: 1 min and 15 s
With the air path opened by half a turn: 27 s
With the air path opened by two turns: 27 s

The time it takes to fill the tank through the side-port (the tank laying in horizontal potion)
With air path in closed position (but no plug): 24 s

Are these numbers similar to your experience Bob?

I have never timed the fill time without opening an air path as stated in the instructions which were printed in English, Swedish, German, French and Spanish. So I can not confirm that. I also never tried filling from the side as that lets the chemistry randomly fall on the film while you can't cause that from top filling.

27 seconds sounds about right. You should also be aware that all Combi tanks, those for roll film as well as the 45 daylight versions were designed to leave an air space in the tank so that when the tank was inverted the chemistry could flow over the film rather then just stay in constant contact with the film. So don't overfill the tank.

[Tobias Key]

I have a combiplan tank. One of the things I have found is that if you load the tank upright it is best to stick to only opening the airway half a turn as recommended in the instructions. If you open it wider you may get faster filling times but you increase the risk of splashing on the negatives creating spots of uneven development. For me this totally counteracts any benefit you might get from faster filling. The most successful method for me is to make sure the developer fills at an even pace, no stops and starts caused by overfilling the funnel. I only use quite dilute developer so that development times are around 10 mins or longer, R5 monobath seems to me to be totally unsuited to the combiplan tank if you use the daylight fill, it is way too active. What you could do is buy a calumet dark tent like this one


https://www.calphoto.co.uk/product/Calumet-Changing-Room/RM1000

and then work out some way of splash proofing the bottom. That would give you a way of immersing the film instantly.

[barnacle]

On the filling times: with the air port closed, filling the combiplan from the top takes me over a minute; with it open, thirty seconds 'give or take' depending how high up the funnel I let the fluid get.

Which confirms some of the numbers given above. It's the main reason I've stopped using the combiplan; the drain takes the same time so, to my mind, the top of the film gets a minute less than the bottom in the soup, graduated over the height - assuming everything is done in the vertical position. I used development times of eight minutes, so that wasn't a serious issue, but I wouldn't have wanted to use a time much smaller.

Neil

[Lenrick]

I developed some Atomic-X in R5Monobath using the CombiPlan following their instruction (vertical tank, filling through the lid-port, air way opened half a turn). The images turned out fine...making the first post in this thread a bit...well...unnecessary.

I did not see any differences between the parts of negative in the lower parts of the tank (longer time in contact with the liquid) and the parts of negative in the upper parts of the tank (shorter time in contact with the liquid). If there is a difference, it is by no means obvious.

The image below is made from two 4x5" negatives. One very simply pasted on top of the other in Photoshop followed by a very simple (about 10 pixel wide) blurring of the line where one negative ended. The two negatives were placed in the tank in such a way that the left side of one negative was in the lower part and the right side of the other was in the lower part. I assume that one would see the blurred line as a fairly sharp change in tonality if the there was a significant difference between top and botton of the tank.