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Bolex EL question


Philip A Borgnes

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Hi,

 

I thought this would be easy to search and find out, but no luck which is why I'm asking the experts.

 

To do time lapse with a Bolex EL, is that a function built into the camera, or is it an add-on with something like a Tobin unit? And would this be true for all ELs, or just a specific model?

 

Thanks.

 

Phil Borgnes

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Hi Phil

There are units out there I think Clive did one, but I know that Anrew Alden in UK has one that goes with EL

 

Intervalometers for the H16 EL (all models) (NEW), these are powered by an internal 9v PP3 battery, crystal controlled with ranges of seconds, minutes and hours and multipliers of 1/4, 1/2, 1, 2, 4, 8, 16, 32 and 64 - therefore the range of interval is 1/4 second up to 64 hours. Momentary closing contact output via internal reed relay, 5 pin Din plug to the camera, £95.00

 

www.bolex.co.uk

 

Regards

 

 

Don

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To do time lapse with a Bolex EL, is that a function built into the camera, or is it an add-on with something like a Tobin unit? And would this be true for all ELs, or just a specific model?

 

The EL has Single Frame option, you simply need to hook and interval switch-interuptor to the remote socket. These units can be found for a couple of bucks in most DIY electronic shops.

 

I use such a thing on my Super8, to use it on my Bolex RX1 I added some electronics plus a RC-servo, it works fine...

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Honestly the parts required are in low double figures - especially if you are ok with the division and/or multiplication series like it seems the Tobin one is made... If you want direct Period or Hz input then you need to use a microcontroller or a bit more elaborate ($$$) chips but still easily under the cost I've seen people attempt to sell them on eBay for - there was one going for $1000 a while back - absolutely ridiculous -

 

Basically its just a relay, SCR or mosfet transistor triggered by a pulse at the freq you require... with a little more electronics you can run servos of the same freq to run your wind ups the same way, switch on and off lighting, change aperture etc...

 

I make mine out of a microcontroller and the tolerances of time are well within the requirements, it ran from about 3fps (a little unstable at this speed) to whatever I wanted (i.e. well untill the battery running it would run out) - a friend wants one which he is currently speccing for its user interface - I may just post the schematic here for you if its simple enough

 

I would note that the EL mechanism isn't exaclty suited for timelapse - the stop mechanism is where a lot of the wear in the EL happens - timelapse uses this function every frame, so if you shoot a 4 sec sequence you are wearing out your EL 96 times as fast as you would have normally shooting it ... Just listen to it, all that energy is being converted into the sound you hear by two parts slamming into each other.

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...I think Clive did one, ...

No, I never did one for the EL after hearing from service people that the camera will beat itself to death if used for extended single frame filming.

 

We still have the famous TTL Tobin Time Lapse motor for clockwork Bolex cameras such as the Rex-4 and 5, M4 and M5 and S4, SB and SBM. This is not just a trigger, it is a complete motor that will run indefinitely if furnished 12 volts DC. It uses a DC servo motor to avoid the vibration problem and high current drain of stepping motors. It can be admired on the website.

 

I have heard of people attaching it to an EBM camera by wrapping a large rubber band around the pair, but this is not an official recommendation.

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the EL after hearing from service people that the camera will beat itself to death if used for extended single frame filming.

 

good to know. I was thinking about getting a EL to do timelaps and stopmotion, but if it kills the camera I'll get a Rex or SBM...

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I have heard of people attaching it to an EBM camera by wrapping a large rubber band around the pair, but this is not an official recommendation.

Having never used an EBM I always wondered what the shafts were for - So they obviously still work, but in this case your motor would be running against the EBM motor wouldn't it ? Or where is the disengage MOT/0 switch ?

 

**edit** just realized the EBM has no reverse setting - so that answers the 'what they are for' question...

 

Another question mark is the purpose of the shaft on the EL ... It is connected to the same clicky stoppy slammy whammy breaky aparty mechanism we are talking about and can only revolve backwards one frame. I'm assuming its purpose is for testing/disassembly ? In the meantime I've found good use for it as a passive 1:1 output for hall effect sensors, but would still like to know about its intended usage

 

any ideas ?

Edited by Nick Mulder
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...your motor would be running against the EBM motor wouldn't it ?...

Another question mark is the purpose of the shaft on the EL ...

 

The EBM does not have any mechanical release parts, it is started and stopped by just switching power to the built in motor, so it stops in a random position of the shutter. It can be driven through the shaft without difficulty as far as I know. The internal motor will just coast in this case.

 

The EL shaft is there, I suspect, because it is part of the usual Bolex pulldown claw and gear mechanism and it would cost more to eliminate it than to just keep it as is. I am not aware of any official Bolex accessory that would fit.

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