Bolex Rex 5/SBM question

Jon O'Brien · October 17, 2017

On a Bolex Rex 5 and SBM, and apparently only on these models, there is a simple mechanical apparatus in the region of the loop-former lever, the purpose of which I don't understand. For instance, the Rex 4 has a different design at this point.

I'm pretty sure Rex 5/SBM Bolex users will know what I'm talking about. There is a sliding metal plate 2cm to the right of the loop-forming lever central button - the button you push to release the loop-formers after threading film. It has a slight lip that pokes up about 2mm, and you can push this plate left and right about 2mm. You can see it in this video, though the film loader never touches it or mentions it:

At 0:19, see the little black screw head to the right of the loop-former release button? To the right of that black screw head is the tiny lip that you can push left or right. It makes a slight click sound as you push it, and is clearly designed to be pushed. But what for?

I've looked at various loading videos and no one mentions it. Can anyone tell me what this sliding plate thing does, and whether I should push it to the left or to the right when loading the camera. I regret, but Bolex camera loading is, so far, not my forte. As mentioned above, the sliding plate is tightened by a black anodised screw approx. 4mm in width. The little plate bifurcates into two little prongs that seem to engage in some fashion with the loop forming mechanism. Any wisdom that anyone can impart on this mystery? As always, thank you.

Jon O'Brien · October 17, 2017

One more question, Bolex users!

This one may seem infuriatingly obvious, but bear with me - I'm trying not to ruin my first roll.

I can load a roll of 50D in subdued light, as in, enough light to see what I'm doing? Correct? Thanks for any advice.

Samuel Berger · October 17, 2017

Are you talking about the audible click selector? Or the spool ejector? Maybe if you upload a picture with something pointing to what you mean we can help.

Samuel Berger · October 17, 2017

One more question, Bolex users!

This one may seem infuriatingly obvious, but bear with me - I'm trying not to ruin my first roll.

I can load a roll of 50D in subdued light, as in, enough light to see what I'm doing? Correct? Thanks for any advice.

If it's in a daylight spool, sure. Just make sure to keep it tight around the spool because if it unravels, you'll waste a lot of the film.

Jon O'Brien · October 17, 2017

It's neither of those things, but thank you for mentioning - I was trying to figure out how to turn off the audible click and just figured it out.

Dom Jaeger · October 17, 2017

That lever lets you lock the two sprung sprocket guides open.

Simon Wyss · October 17, 2017

That lever lets you lock the two sprung sprocket guides open for inserting the film loop from a mag. You have a model with magazine saddle.

Else, you do the same mistake as many others, unfortunately it was given to the world by Paillard.

Don’t put the full spool on the spindle first but keep it in your hand, holding the film down with little finger. Pull a few inches for making the diagonal cut. Present the film to the running mechanism very shortly, so that it just holds on the first sprocket drum, stop mechanism. Now place full spool down, tighten the film lightly, and release mechanism again to complete threading. Once film leaves second drum, stop mechanism. Open loop formers, restart mechanism, check for good transport, run about a foot of film, stop. Attach film to empty spool, put spool down, hand wind up slack film, and run for another second to check whether film is taken up. Replace lid

Be so kind to your camera to not let it dangle around on a hard surface. Place it on your legs when sitting or crouching, the lenses pointing away from you. That is a good position. Reason for crouching? Everything falling will not fall far. Out in the wilderness you rather want a dusty cover lid than one with bent dogs.

Edited October 17, 2017 by Simon Wyss

Jon O'Brien · October 17, 2017

Those bent dogs sound scary, I will avoid those! :o :)

Thanks Simon and Dom.

Could you describe in some more detail what you mean by springing open the sprocket guides? When I push this to the left and to the right, about 2 or 3mm of travel, absolutely nothing seems to happen to the mechanism. Nothing locks or springs open or closed. In case there is any confusion, I'm not talking about the lever that swings down to close down the loop formers.

If we are talking about the same thing, should the "lever" (I wouldn't call it a lever, I'd call it a sliding metal piece that is held down by a black anodised screw) be pushed to the left or to the right before threading the film into the top sprocket wheel? Thank you! Sorry, I'm not too mechanically savvy in some ways.

Dom Jaeger · October 17, 2017

Try pinching the two chrome knobs together that are next to the sprockets, so that the guides open. Then push that lever towards the gate to lock them open.

Jon O'Brien · October 18, 2017

Ah-ha! Eureka. I see now Dom and Simon what you are saying. Thanks!

Simon, I didn't read carefully enough what you wrote, until just now. So this sprocket guide lock (the bifurcated sliding lever) is only used when using the 400 ft magazine? I can't figure out how on earth why, but will leave that query for another day.

So in a nutshell, to quote Austin Powers, I don't need to touch this lever lock at all if using 100 ft daylight spools - I just leave the two sprung sprocket guides unlocked and in the far right hand position and thread the film the standard way?

Simon Wyss · October 18, 2017

Jon, you should learn to read more slowly, more carefully, I have written for inserting the film loop from a mag.

Your loving mentor.

Jon O'Brien · October 18, 2017

Ah-ha yes, the penny has dropped, now I understand. Thank you Simon.

It is for threading the LOOP straight through, as if loading a Panaflex or something like that. I get it. Thank you, mon amie.

Simon Wyss · October 18, 2017

Mon ami, male. Amie is female, the e at the end makes the difference.

French from Brisbane, how comes?

Jon O'Brien · October 18, 2017

Sorry! My mistake. I typed "my friend" into a French translator and that is what came out. Merely a faux pas on my part. I'm not French and indeed of Irish stock mostly. You coming from Europe, and far away from Australia, I had a mental image of Hercule Poirot for some reason, and typed that welcoming phrase without giving it much thought. It was not meant to be offensive or to be humour at your expense, or indeed anyone else's. You see, like anyone else, Australians can put their foot in it, so to speak, when writing!

Edited October 18, 2017 by Jon O'Brien