What's this line on my Rondinax devved shots?

[ChrisR]

A few times when I've devved a film with my Rondinax 35 tank, I've seen intermittent white streaks going partway across the frame. This happened the first time with a film from the Stratford meet (although on that film it appeared as a double streak, not since repeated), that I thought might have been a light leak in the tank or camera, or maybe a scanning artefact. It has appeared with different films from several different cameras, but not all films by any means. I'd really like to know what it is (and how to fix it), as it could easily ruin some nice shots.

This particular film was from an Ilford HP5+ Single Use Camera, and loaded sweetly onto the reel (so little danger of parts of the film coming into contact with other parts, as happened when I forced a jammed film onto the reel). There's no mechanical component of the reel that I can see that could be responsible. The streak appears in different places on different frames, but not all frames. Here are two examples:





I devved two more films yesterday, but have not yet scanned them.

Any ideas?

 

[abdoujaparov]

It'd be interesting to know if the streaks are at regular distances apart on the film - check before you cut the next one.

 

[ChrisR]

That's an interesting thought, Keith. It's not easy to see the streaks on the negs though; just faint dark lines...

 

[abdoujaparov]

That's an interesting thought, Keith. It's not easy to see the streaks on the negs though; just faint dark lines...

you could estimate it from the scans, if you can reconstruct the order they were shot in. It just occurred to me that if there was some blockage/warping, it could allow a tiny light-leak every full rotation of the reel (or similar) which means you'd see a pattern.

 

[ChrisR]

Not sure that's possible, given the nature of the Rondinax tank... but then something "impossible" is happening, so what do I know!

The reel in a Rondinax tank has a horizontal axis, and the film is fed in from canister in a separate compartment at the top. If I've remembered to bend the corners of the film down, it's a fairly quick process from closing the tank to the entire film loaded and cut from the canister (takes about a dozen or so winds). Thereafter it's semi-continuous rotation, as the chems only go half way up the tank. I usually give two partial winds a second apart, then wait two seconds and repeat. It works out at one full rotation about every 5 seconds. And of course, by its nature the earlier parts of the film are shielded by the later, outer parts of the spiral, so you'd expect light leaks to mostly occur in the outer parts.

 

[StephenM]

I've watched a YouTube video on a Rondinax tank today because this thread made me curious about how they work. I still haven't seen the spiral though; but if it is a spiral similar to Paterson et al, then I'd expect the frames nearest the centre to be closer together than those on the outside. Badly expressed, but I hope you can see what I mean.

I thought I saw other streaks on the second photo, which made me think bromide drag. But that seems also unlikely to me, given that the Rodinax seems to be continuous agitation. Although, there is agitiation and agitation - I suppose that the developer does get changed as you rotate, rather than being sloshed around? Given that it's supposed to work on half a tank of developer (as I understand it) this also seems unlikely.

It's an interesting problem.

 

[ChrisR]

Although, there is agitiation and agitation - I suppose that the developer does get changed as you rotate, rather than being sloshed around? Given that it's supposed to work on half a tank of developer (as I understand it) this also seems unlikely.

Not quite sure what you mean by "developer does get changed"? The rotation is gentle, unlikely to cause any wild sloshing, but I'd have thought there'd be plenty of mixing going on.

 

[steveo_mcg]

Is the film kinked where the line is?

 

[ChrisR]

Is the film kinked where the line is?

No, looks absolutely flat.

Two more clues occurred to me. If it was bromide drag the streak would surely be along the negs rather than across, as the frame travel longways round the spiral, in and out of the chems.

Secondly... not quite sure of this, but when I have done two or more films in one go (one after another, can only get one film in the tank at a time), I only remember streaks on the first film. I did 3 films Monday, not yet finished scanning the 3rd film, but don't remember obvious streaks on the second.

 

[StephenM]

Post 4 in this thread might be relevant.

 

[ChrisR]

Post 4 in this thread might be relevant.

That post said:

Hello,
the Rondinax 35 has 4 problems:
1) If you rotate very even and uniform it has a tendency to make stripes due to laminar flow.
2) The seals may have deteriorated and the tank may leak.
3) The rubber band from the clip may heve deteriorated.
4) The little knife for cutting the film may be not sharp.

1) I think laminar flow would go along rather than across the frame.
2) I guess I'll have to have another look at the tank to see what any seals look like, though it's not (quite) clear whether they mean light leak or chems leak; I'm certainly seeing nothing of the latter, and the fact that the other two films appear OK is confusing.
3) It's more a plastic strip, but the bit around the clip did fail. I stapled it, which is NOT a good solution...
4) The knife seems quite sharp, but I have to remember to move it several times while the tank is empty, as it seems to jam and refuse to cut, sometimes.

 

[ChrisR]

I sent an email to Malcolm Peaker, the owner of the Rondinax site and blog, and he's put it up on his blog with a link back here. But he did suggest thinking again about light leaks in camera... This was my reply:

Malcolm suggested this might possibly be a camera light leak. Because it had happened to me before using the Rondinax, I hadn't given this much consideration, but it's certainly worth thinking about. The camera in question was not the highest grade device imaginable! It was an Ilford Single Use Camera loaded with HP5+...

It's worth remembering that these cameras are loaded with the film fully wound out of the cassettes, and as you shoot the film winds back in, so that when you crack the camera open the film is in the dark inside the cassette. This makes it easier to avoid getting a shock from the capacitor for the flash!

I've been through an checked the frames with streaks. In the little table below, I try to show the frame number as I saw it (ie 1 is first), the corresponding actual frame number on the film (not sure if this is important, but hey), the position of the streak across the film, where 1% would be the extreme left and 99% the extreme right, and a rough time since the previous shot (light leaks in cameras are usually worse when there has been a delay). Sorry, this is a bit long:

No Frame Position Time
2 26 90% 2 min
5 23 20% 5 days
9 19 60% 20 min
11 17 95% 2 days
14 14 40% 30 secs
16 12 60% 20 min
20 8 80% 20 min
22 6 60% 10 min
24 4 80% 1 min
26 2 60% 5 min
27 1 90% 1 min
28 0 60% 1 min
29 00 60% 1 min

Looking at the partly-cracked-open camera, there IS a possible suspect, a seam along the left hand edge, presumably near where the film was originally wound out. It's possible that light leaks are happening onto the frame before it's exposed, so the time since previous exposure might not be relevant (you'd want the time since the exposure before that). The last half dozen were all taken within half an hour or so.

What does this mean? I don't think it confirms a light leak in camera, but it probably does make it more likely, particularly since we're struggling to explain how such a streak could otherwise be formed in the Rondinax! I guess unless I can find a better explanation I'll have to carry on as before.

BTW in case you wonder, the single use camera is for a challenge on the Talk Photography forum, not what I normally use...

End quote

 

[StephenM]

Surely if it's happened as you say with a number of different cameras, it's more likely to be the one common factor (the tank) than that several cameras have light leaks?

 

[Cuchulainn]

I had an intermittent light leak on a camera I was working on before. Turned out that the leatherette was needed to make it light tight. On frames that I took relatively close together, my hand covered the leak and those frames were OK, but ones where I put the camera down or left it for a few days were affected.

 

[ChrisR]

Surely if it's happened as you say with a number of different cameras, it's more likely to be the one common factor (the tank) than that several cameras have light leaks?

This prompted me to go back and check. A couple of films had a suspicion of streaks, but it appears that I've exaggerated previous problems in my mind. The major problem was a film taken at the Stratford meet, see for example this one (and note Andy's subsequent comment, which sent me off in this direction, perhaps). Note, the camera showed no subsequent problems (he said hastily, since it's for sale in the Classifieds!).

 

[ChrisR]

I'd more or less decided that the Ilford single use camera was responsible for the light leak. However, annoyingly, I've just devved the film from a Rollei single use camera in the Rondinax tank, and several frames have the white line on them. Looking at the negatives, one otherwise completely clear negative has the white line on it, as does the next-but-one (IIRC, will correct if wrong), 83mm away.
The Retro 400S needed over 12 minutes, so I guess there would be plenty of opportunity for the leak to take effect (although the film was not [EDIT] stationary in the tank for longer than a few seconds).

I did have a problem, in that the Rondinax cutter refused to cut the film (apparently it's a synthetic base), and I had to improvise a darkroom, lift the lid off the tank and cut it with scissors. I suppose you could blame that for the leaks, except for the fact that there are several of them, extending only part way across the frame, rather than a splodge or a flare.

This is annoying me!

 

[ChrisR]

Bother. The very slight hope that rubbish single use cameras with light leaks were the problem has been dashed. Just scanned yesterday a film devved in the Rondinax at the weekend. Two of the shots show the white streak, though a slightly different shape this time (frames 17 and 28 of 37). I've looked carefully and can't see it in any other frames.



I did look carefully at the tank before using it this time. I can see no replaceable seals at all; just a snug fit of the lid over the tank. There is of course the knob that allows turning of the spool inside. Perhaps I should dis-assemble that and see what I can see.

Thinking back to the two previous dev sessions with the single use cameras, I remember thinking at the second one that there was fairly strong sun coming in from the side (I usually do the dev sessions in the laundry/utility room, which has a side window, and do it in the morning when the wife is out). This time I left a plant in place that usually sits on the draining board, and shaded the tank. My idea was to keep the temperature stable, but it might have had the effect of reducing the light leak. But I still can't see a way for the light to get in.

 

[StephenM]

You could always develop an unexposed film and see if that has any streaks.

If the film is constantly in motion during development, it seems to me that this rules out a constant light leak. If it came about as a result of variable shading of the tank, then that shading was removed only twice during developing the last film, which seems unlikely. If there is some way that intermittently (and not very frequently) the action of turning the knob could allow light in, that might explain it (once every 100 turns or whatever). This would also seem to be a non starter though if the streaks occur on frames that are well inside the spool (and hence would be shaded by outer layers).

I've never seen a Rondinax tank other than in photos and never examined one.

Edit to add: Looking at the examples, the streak never reaches the edge of the film. Is this significant? Not that I can see how it could be.

 

[abdoujaparov]

Edit to add: Looking at the examples, the streak never reaches the edge of the film. Is this significant? Not that I can see how it could be.

If this is how Chris's Rondinax looks

http://i.ytimg.com/vi/1H-QYvVcRtg/maxresdefault.jpg

then the guide rails for the film look like a prime candidate for shielding the edges of the film. can you hear any creaking of plastic-on-plastic, Chris, that might be some tiny deformation that allows an intermittent leak between the lid and the body?

 

[steveo_mcg]

It looks to me like the film is being folded. When I mess up loading to the spiral and kink the film it looks just like this.

 

[ChrisR]

Thanks Stephen and Keith. Looking at that last picture (which I'd seen before but had forgotten, and of course don't normally see with the lid on) gave me an idea, the beginnings of a theory that might fit the facts. As it's winding onto the spool, the film travels over the slot with the knife in it (a lever under the tank pushes the knife up to cut the film when it's all wound on). It takes me a dozen or more turns of the winder to get a 36-shot film onto the spool, before cutting it away. After each turn there's a small pause while I change my grip on the knob. It's possible there is a light leak coming up through the knife slot, not enough to spoil the whole film, but enough to have an effect during the pauses. If so, it would certainly be amplified if bright light was shining onto the tank. It would explain how inner parts of the film were affected, which is something that has completely boonswaggled me so far.

I can test this by (a) getting the tank out and having a look down the slot against a bright light, and (b) next time I dev a film, covering the end of the tank where the knife slot is, and/or (c) winding film into the tank in darkness.

 

[ChrisR]

It looks to me like the film is being folded. When I mess up loading to the spiral and kink the film it looks just like this.

It's Delta 400: beautifully flat, not a sign of a fold or crease! A dream to scan, it just drops into the holder and sites there snugly.

 

[Cannyekerslike]

Hi Chris,
My instructions state that loading the film into the tank should not be carried out in bright light or direct sunlight.
These are the instruction that I got with the tank, I always did it in subdued lighting, curtains pulled in daylight etc.......

 

[steveo_mcg]

It's Delta 400: beautifully flat, not a sign of a fold or crease! A dream to scan, it just drops into the holder and sites there snugly.

Run your finger up the line on the negative , is there any hint of indentation?

 

[ChrisR]

Run your finger up the line on the negative , is there any hint of indentation?

Nothing at all, no hint of a crease when letting light fall on either side of the film either.

Hi Chris,
My instructions state that loading the film into the tank should not be carried out in bright light or direct sunlight.
These are the instruction that I got with the tank, I always did it in subdued lighting, curtains pulled in daylight etc.......

Ah! Obviously I didn't read that bit well enough. RTFM, as they say!

I've had another look at the tank, specially trying to see some light through the knife slot. Nothing visible, but I think it would be hard to get the conditions right. Since it's the only explanation so far that explains how light streaks could get onto the inner parts of the negative, I'm going with it, and will obey those instructions next time.

Thanks for your help, folks!