Paterson Super System 4 Tank Design Flaw?

[gary green]

I recently purchased a Paterson developing tank and have processed 4 rolls of 120 b&w film in it (from various cameras).  1 roll was processed using the spinner and the rest were processed using inversion.  For all rolls, I gave a 5 minute presoak in tap water with the lid off (light-tight funnel was locked in place).

For all rolls, I have observed a light leak on the edge of the film that is towards the bottom of the tank.  Here is an example.

The other edge of the film, on the top side of the reel as it sits in the tank, is clean/clear.  As you can see, some of the light leak bleeds into the picture area.

I took a closer look at the design of the tank and noticed that the center tube does not rest flush on the bottom of the tank but rests on slightly raised platforms.  I assume this is done to allow solution to quickly enter the tank since the tube is solid.  The flared end of the tube does rest in a shallow circular depression which I assume is there to act as a light trap.

Being curious as to how light-proof this design is, I turned off the lights and shined a penlight down the tube.

As you can see, the design is not fully light-proof and there is leakage around the bottom of the tube.  I suspect this may be the cause of the fogged edges on one side of my films.

Has anyone else observed this issue with the Paterson tank design?

Thanks,

Gary

[randy_boren1]

Do you have a bright light directly above where you develop your film? I have used the older style Paterson tanks for 40+ years and have not had any fogging. As a precaution, I make sure that there are no lights above where I process film. I also see 2 faint narrow bands of density at the center of the neg. To me, fogging is much more noticeable, spread out, veiling the image. Does the edge density run the entire length of the film? It is a mystery.

[Niels - NHSN]

I can assure you that Paterson tanks are as light tight as they need to be when used according to instructions.

The center column light trap design is carried over from their previous System 4 to Super System 4 and I have used both systems for a combined 50 years without a single incident that could be attributed to the design.

I think you need to look elsewhere for a source of your problems. I hope you find it.

A different matter: I have found Paterson reels almost impossible to load with 120 film when there is the slightest residue in the rails. Drying them separated so water can run out of the rails with the help of gravity helps. Occasional running a tooth brush in the rails when washing helps as well. 

 

Edited October 21, 2022 by NHSN

[kmac]

12 hours ago, gary green said:

Being curious as to how light-proof this design is, I turned off the lights and shined a penlight down the tube.

Perhaps a more conclusive test would be to sit the penlight in the tank with the funnel and center tube locked in place then turn the room light off and wait 5-10 minutes for your eyes to adjust and then check for light leaks around the edge of the funnel. My guess is that light won't leak past the funnel because there's two right angle shoulders the light would have to filtrate past. Which edge of the film was affected, was it the top or bottom edge? If light got past the funnel, the top edge of the film would be much more affected than the bottom edge. 

Edited October 21, 2022 by kmac

[Dustin McAmera]

Are you sure it's a light leak? The streakiness of it makes me wonder if it isn't chemical. Is it all the way along the film? If it's a light leak via the centre column, you'd expect the end of the film at the centre of the spiral to be affected worse than the other.

Even though you don't think these are the problem, it might be worth telling us what film, what developer, concentration and agitation details.

[gary green]

Thanks everyone for your input.  I am not certain that the tank design is the culprit.  That's why I posted the question to other Paterson tank users.

However, I was surprised at how much potential there is for light to leak past the filler tube at the bottom of the tank.  Also, for my tank, when the funnel is locked into position, it does not clamp down on the filler tube and there is some play.  This is necessary if one wants to develop using the spinner.  However, when pouring solution into the tank, I can imagine the flow pressure at the bottom of the tube causing it to lift slightly which would allow even more light to leak in.

I will probably need to develop a roll in complete darkness to perform a comparison.

[keith__richard_terry]

I never experienced a light leak all the time that I used Paterson equipment and I always developed film in a room lit by daylight or artificial light.

I did however notice that there was some leakage of solution occasionally which I never experienced when I changed to Jobo tanks.

[q.g._de_bakker]

My only problem with Paterson tanks too is that they leak. But liquids, and not light.

[jose_angel]

16 hours ago, gary green said:

Has anyone else observed this issue with the Paterson tank design?

Never. Paterson tanks user since... eighties? I think in the seventies-early eighties I used to use baquelite ones. Always with room lights and without the lid but with the spin driver or a thermometer in place.

2 hours ago, gary green said:

However, I was surprised at how much potential there is for light to leak past the filler tube at the bottom of the tank.  Also, for my tank, when the funnel is locked into position, it does not clamp down on the filler tube and there is some play.  This is necessary if one wants to develop using the spinner.  However, when pouring solution into the tank, I can imagine the flow pressure at the bottom of the tube causing it to lift slightly which would allow even more light to leak in.

I think you are right in your insights; there is also some play in the funnel 3 point locking that I use as indicative that it is correctly attached. But as said above, I think Paterson tanks are as light tight as they need to be.

But it is true that with all the tanks I use I try to avoid direct light over the filler... just like some kind of fear that photons could enter on the tank. Same with Jobo tanks.

2 hours ago, gary green said:

I will probably need to develop a roll in complete darkness to perform a comparison.

Or just develop a cut of unexposed film. Do not place the tank directly under the light.

BTW...

Could it be a camera light leak?

Is the filler tube Paterson original? (I have a filler tube that is Paterson style but not identical!)

Personally, the Paterson is great for spin agitation. For hand invertion I prefer the Jobo.

Edited October 21, 2022 by jose_angel

[kmac]

26 minutes ago, q.g._de_bakker said:

My only problem with Paterson tanks too is that they leak. But liquids, and not light.

The older Paterson tanks had a pliable plastic seal under the lid to prevent chemical leaks, but those seals can harden over time preventing a proper seal. Either that, or the seals came in varying hardnesses from the factory and you had to be unlucky to get a less pliable one with your new tank.

Of the three seals I have, I chose the softest one and only use that one for my two old Paterson tanks. That softer, more pliable seal stopped my tanks from leaking. Chemical leaking was also a problem with the top cap, but I found that it needed a little more downward pressure to stop that cap from leaking. As with the seals, there are hard caps, and soft caps, and again, I chose the soft cap out of the two I have of those.

[kmac]

2 hours ago, gary green said:

However, I was surprised at how much potential there is for light to leak past the filler tube at the bottom of the tank.  Also, for my tank, when the funnel is locked into position, it does not clamp down on the filler tube and there is some play.  This is necessary if one wants to develop using the spinner.  However, when pouring solution into the tank, I can imagine the flow pressure at the bottom of the tube causing it to lift slightly which would allow even more light to leak in.

I see what you mean, I just checked with my mini torch shining down through the center tube, in the tank, and I could see light at the bottom of the tube when I lifted it up about 1/4". The vertical movement of the tube seems to be less than that when the top is screwed on, about an 1/8" to 3/16", so you really wouldn't want any room light directly overhead, and never shine a torch down the tube to check the level of the chemical.

I doubt the liquid flow would lift the center tube with the loaded spiral attached, there's a 1.5mm gap at the bottom of the tube to allow the chemical to flow freely without putting upward force on the tube. I don't pour the chemicals in that fast, I pour gradually to prevent bubbling and splashing. I'm certain I've never had a light leak problem in my tanks. Only once when I developed a piece of sheet film without a spiral, and forgot to fit the center tube, durrr

[q.g._de_bakker]

All Paterton tank seals are made of not so soft plastic. A compromise, trading off sealing against durability.

It's a given. You must use these thingies on a table top that doesn't stain and cleans easily.

[maris_rusis]

I've used Paterson tanks, old style System 4 and new style Super System 4, since the 1970s and have never seen a light leak. But out of the thousands of 120 films developed over the years maybe a hundred or so show a bit of edge fogging on one or both sides. The cause for me has been the so called "fat roll" problem. Some cameras don't put enough tension on the film which means the take-up spool isn't wound tightly enough and some light can sneak past the edges of the backing paper and touch the film. The light strike happens when unloading the camera.

[Niels - NHSN]

On 10/21/2022 at 1:04 PM, gary green said:

I will probably need to develop a roll in complete darkness to perform a comparison.

Complete waste of time IMO. The culprit is elsewhere in your process.

If you do this experiment and the negs comes out fine you will have arrived at the wrong conclusion.

There are several things you can complain about re. Paterson tanks - but they are as light tight as they need to be.

[rodeo_joe1]

On 10/20/2022 at 9:22 PM, gary green said:

For all rolls, I gave a 5 minute presoak in tap water with the lid off (light-tight funnel was locked in place).

1. There's no need for a presoak. 

2. The funnel without lid is only meant to be light-tight enough to briefly pour liquids in and out of the tank. Not to stand under room lighting or daylight for a full 5 minutes.

3. "Twizzle stick" agitation is pretty inefficient and useless, and can give rise to standing wave density variations in the negatives. 

[gary green]

2 hours ago, rodeo_joe1 said:

2. The funnel without lid is only meant to be light-tight enough to briefly pour liquids in and out of the tank. Not to stand under room lighting or daylight for a full 5 minutes.

Hi Joe,

Paterson advertises the tank as suitable for either spin or inversion agitation.  The lid must be off to operate the spinner.  I don't recall anywhere in their instructions where it says to repeatedly remove/install the (liquid) leak-proof lid every 30 seconds or so when you operate the spinner.  That would be a tremendous hassle.

I believe their claim is that the tank is sufficiently light-tight with just the funnel locked in place.

Gary

[Niels - NHSN]

1 hour ago, gary green said:

I believe their claim is that the tank is sufficiently light-tight with just the funnel locked in place.

Gary

Correct, you don’t have to put the lid on between spinning cycles. You can do it under normal lighting conditions.

[rodeo_joe1]

8 hours ago, NHSN said:

Correct, you don’t have to put the lid on between spinning cycles. You can do it under normal lighting conditions.

Yes, but when you have the 'twiddle stick' inserted it blocks a lot of light from the funnel opening. 

Anyhow, I gave up on sticky-loading Paterson spirals and their crazy ball bearing rachet system years ago. Jobo spirals are much smoother to load, but neither are as friction-free as stainless steel reels. 

[jose_angel]

Yes, the little balls on the spirals need to be loosened -just before- loading the film...they tend to get stuck. With the tip of a pencil I move them to the widest side of the casing to make it work. No problem.

Edited October 24, 2022 by jose_angel

[Niels - NHSN]

12 hours ago, rodeo_joe1 said:

Anyhow, I gave up on sticky-loading Paterson spirals and their crazy ball bearing rachet system years ago. Jobo spirals are much smoother to load, but neither are as friction-free as stainless steel reels. 

I changed to Hewes and LPL steel reels when I started to do more 120.
Even the slightest residue in the Paterson rails provides sufficient resistance to make loading close to impossible with 120, less so with 35mm.
Good cleaning practice is key for problem-less use of Paterson.

[rodeo_joe1]

16 minutes ago, NHSN said:

Good cleaning practice is key for problem-less use of Paterson.

That, and the spirals have to be bone dry, so not very useful for a rapid throughput. 

There was a recommendation at one time to spray the reels with silicone furniture polish. It did seem to help when I tried it, but the effect was short-lived and just added to the tedium of using 'em. 

When I went to study photography at college there were only stainless reels available, and after I mastered loading them I never looked back - except when I later got a Jobo CPE2 to process colour film, which required using Jobo's plastic spirals and tanks. But they were much larger in diameter and several times easier to load. 

Did anyone ever successfully load a 220 film on a plastic spiral, I wonder? It was tricky enough with stainless reels. 

Edited October 24, 2022 by rodeo_joe1

[Dustin McAmera]

I blamed my trouble with Paterson spirals on humidity from my sweaty hands in the black bag, though I did ok with brand-new reels. Some became completely unusable (I may have cleaned them too vigorously, and jumped from one cause of trouble to another).

It's a special kind of panic, when your film, carrying your whole day's effort, is open in the bag, and the only way forward doesn't work.

 

[Niels - NHSN]

1 hour ago, Dustin McAmera said:

I blamed my trouble with Paterson spirals on humidity from my sweaty hands in the black bag…

Yeah. Never overestimate how much work you can do in the bag at one time. I never realized how much my hands can sweat before I started using a changing bag 😅 

Edited October 24, 2022 by NHSN

[Tony Parsons]

Acting on advice from a local camera dealer (remember them ?), I used to use very thin latex gloves in the changing bag, which mitigated the entire sticky fingers problem, and with care they could be washed and re-used. I always used talc instead of more expensive French Chalk (as I did when replacing inner tubes on my bike) - must have had the only Sandalwood-scented wheels around.

[q.g._de_bakker]

I never used gloves in 45+ years of using Paterson tanks. The only thing i noticed is that indeed, the reels need to be bone dry. So i got many, and when still not enough used a hair dryer to get them dry enough to load more film.