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Bolex H16 Jitter and shake


David Dominguez

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Hello everyone,

I recently shot a test roll on my REX 5 H16 Bolex that unfortunately came back with jitters. The surprising  thing is that that it starts to get more shaky the more the roll progresses. The beginning of the roll seems free of any unwanted shake. 

Everything was shot on a tripod, and the pressure plate was secured.

You can see some of the footage here https://vimeo.com/420907018/6bdd739096

Any ideas of what can be causing it? Thanks a ton in advance

 

 

 

 

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Since the footage was fine at the start of the roll it’s probably just dirt buildup or debris in the gate. It looks like lateral instability (side to side) rather than vertical, so first thing to check is the lateral guide - the chrome cage around the gate that has spring leafs that exert pressure on the side of the film to keep it steady. Make sure it’s not full of dirt/emulsion or that it hasn’t been deformed. Make sure the gate is clean too.

If the issue continues, probably best to send the camera to an experienced technician to check all the aspects of the film transport path.

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25 minutes ago, Dom Jaeger said:

Since the footage was fine at the start of the roll it’s probably just dirt buildup or debris in the gate. It looks like lateral instability (side to side) rather than vertical, so first thing to check is the lateral guide - the chrome cage around the gate that has spring leafs that exert pressure on the side of the film to keep it steady. Make sure it’s not full of dirt/emulsion or that it hasn’t been deformed. Make sure the gate is clean too.

If the issue continues, probably best to send the camera to an experienced technician to check all the aspects of the film transport path.

thanks for the response Dom. 

There was no dirt buildup or debris in the gate nor does it look deformed to my knowledge. I've attached a few photos HERE to get a closer look.

 

Can you tell me if you see anything that looks out of whack? I really appreciate the help! 

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I find it hard to diagnose problems without actually seeing the thing in front of me. It looks OK as far as I can tell. 

Here's a lateral guide I just removed from a camera I happen to be working on: 

IMG_0360.jpg.491f7c3e7851ba8668e0c16cb3ff1f26.jpg

You can see how much dirt and dust can accumulate where the guide fits around the gate. (Yours looks much cleaner.) At the ends of the gate and on either side, the guide leafs crimp in to clamp on the edges of the gate (which should be 16mm wide, with a small under-tolerance). 16mm film stock is typically 15.97mm plus or minus a few hundredths, so there should be a tiny amount of wiggle room between those crimped ends so that the film can smoothly slide along the gate without being squished or bowed. However you don't want too much room (or too little), which can happen if dirt gets in between the gate and the crimped in ends of the guide, or if those parts get bent out of shape.

At the point where the claw engages the film perfs (the bottom left nylon insert in the pic above) there is a long spring leaf that pushes gently on the side of the film. The gate itself narrows at this edge to allow the spring leaf to close further in than the nominal film width. Again, if dirt is stopping the spring from closing on the film it will not be able to do its job of keeping the film laterally stable. This stabilisation point is a couple of perfs below where the gate aperture is (in the picture above the bottom of the camera would be to the left), so if there is too much play at the top of the gate for example, the film may still exhibit some jitter even if held by the spring.

So all those areas where the guide cage contacts the gate need to be clean and free from dirt.

If your film is old there may be some shrinkage that could could affect lateral stability too. 

It's possible a film chip or some other piece of crap got stuck in the gate for that part of your film where it got jittery. If you've cleaned the gate and the pressure plate and feel happy nothing is gummy or seems out of place I'd shoot another test and see if the issue remains.

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From what I can see on your photos the claw is possibly bent. Load camera, disengage spring motor, pull side release to M, put on rewind crank and observe claw act on film while turning crank slowly. I use clear or white leader film for that purpose. The claw should work laterally centered in the perforation holes. If that is not the case, remove claw cover sheet, undo claw screw, and pull claw from its stud. Carefully bend back and check against film in the gate. Adjust and recheck until correct

Make sure to place everything back in the order it was. DO NOT PRESS OR PULL ON THE CLAW LIKE THAT, you could bend the stud which would demand a replacement of that part.

If you care for a trained person’s job, I’ll happily do that for you. Please send me a PM first

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A bent claw could certainly cause problems, though I don't know how it could happen in the middle of a roll. Worth checking though. 

Worth checking how the overall film transport is functioning really,  by either running dummy film through at the slowest speed or better yet manually cranking as Simon describes.

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4 minutes ago, Tyler Purcell said:

I agree with Dom and Simon, both have great ideas. 

Has the camera ever worked fine or is this a new thing? 

This is the first time I’ve shot on this particular camera. I Purchased it on eBay a few months ago. 

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1 minute ago, David Dominguez said:

This is the first time I’ve shot on this particular camera. I Purchased it on eBay a few months ago. 

Ah got ya, so it could be anything. Just double checking that this problem isn't something new. 

Ohh and also... what were your loop sizes like? Maybe you're just dealing with a slightly tight loop. 

Edited by Tyler Purcell
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10 hours ago, Tyler Purcell said:

Ah got ya, so it could be anything.

Not anything,

the film jitters mainly sideways. It’s either lack of lateral guidance that allows the strip to swerve under the claw load which acts far off the film’s center line or an active force such as the claw pushing into the hole corner rounding. Too short loops would be caught up by the lateral guide until the lower loop restorer gets into action or the upper one pulls on the pressure plate. In that case you’d have focus issues.

Rather not the loops but a geometrical thing. Too narrow film is a possibility, improbable because a color negative stock is in play that presumably was fresh. The cage could be worn, something you can’t see.

Edited by Simon Wyss
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17 hours ago, David Dominguez said:

thank you both for your help. This job seems like it's for a pro and not me.

Any recommendations on a great tech based in the US? 

I'm not from the US, but I believe Procam and Chambless were for many years the authorised US Bolex Service centres, with very experienced techs. I don't know if they are still actively servicing cameras, and they are a bit far from you in Brooklyn.

Jean-Louis Seguin (who posts here sometimes) is a very good, experienced Bolex tech in Montreal - bolextech@gmail.com

More locally you have Super16inc and Du-All who both service Bolexes I believe, or Visual Products over in Ohio. 

But maybe someone actually from the US has better recommendations. ?

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3 hours ago, Simon Wyss said:

Not anything,

What I meant was because the owner hadn't tested the camera before, there wasn't a "known good" status given to it. Thus, the list of probable causes isn't as straight forward as (it worked yesterday and now it doesn't), which is the case in most camera services. 

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So I got it repaired by a local camera tech . He said the gate was a slightly too big and caused the left to right jiggle so he replaced it. He said he's seen that problem with newer model bolexs

I'm going to run another test roll when I get her back 

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David, thanks for reporting

I wouldn’t have thought that it would happen but your camera is another proof of a conceptual awareness weakness with Paillard & Cie. I had already an H on my bench with a too wide aperture plate. Among other faults such as a nonmachined surface of the part, an insufficiently polished prism (no. 10,005) or wrong aperture dimensions in front of the focusing prism (same no.) this is one more example. Have presented the case on a German forum. https://www.filmvorfuehrer.de/topic/19563-die-paillard-bolex-h-st/#comments

Dom Jaeger was closest to the problem. The aperture plate must not be wider than 0.627" or 15,9258 mm so that film of minimal standard width is still held. The metric value given by ISO 69 is 15,925 mm. I grind plates down to 15,920.

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16 hours ago, Irene Papaefthemiou said:

David - did you run another test roll? I had the same issue and just found this thread. The repairman said the problem was that the film guides were too loose. I am really hoping he fixed it and I'm running a test soon too.

hey!

yes like i mentioned above the gate was slightly too large and gave the film a bit of a wiggle. Apparently it's not that uncommon on the REX 5. Hope that helps! 

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