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Buying film for Bolex, and other questions


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#21 Simon Wyss

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Posted 05 November 2017 - 02:55 AM

Now that’s technical thinking, along what one has. Regardless of the opening angle radially straight edges cause uneven exposure times across the image line intersected by those edges. With the ARRIFLEX, CINEFLEX, and the early Arriflex 16 designs the intersection goes over the image height, with a Camerette/Caméflex Eclair and most other younger designs it goes over the image width. I do not know of a movie camera that has a simple disc shutter whose axis lies somewhere within the film’s width. The bigger the opening angle is, the smaller the difference in exposure time becomes. As you say, only towards almost closed do we have a noticeable error. One should study fades. What a cool job  . . .


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#22 Carl Looper

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Posted 05 November 2017 - 01:47 PM

If the angle of the shutter blades is such that only one blade can intersect the film frame at any given moment, then a radial design seems to me optimum. For any given moment in which one blade splits the frame in two (between shadow and exposed), one can find a reciprocal moment in which the other blade has divided the frame in the exact opposite way. It would only be when both blades are intersecting the film frame at the same time, that they can no longer act as the inverse mask of each other.

 

C


Edited by Carl Looper, 05 November 2017 - 01:50 PM.

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#23 Carl Looper

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Posted 05 November 2017 - 03:17 PM

So here's a graphic visualisation of the logic I'm using.

For any shutter orientation (left column) can be found (at some other time) a shutter orientation (right column) which exactly counter balances the exposure given by the orientation in the left column.

But if both edges of the shutter occupy the frame at the same time (third row), there is no such counter balance to be found (at any other time). This motivates an alternative to a radial design. 

 

 ShuterModel.png


Edited by Carl Looper, 05 November 2017 - 03:25 PM.

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#24 Jon O'Brien

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Posted 05 November 2017 - 08:39 PM

Just a quick question, probably a dumb one but I've looked around the internet and can't find the answer. Haven't read the preceding posts yet but will, with interest, later on. So here's my question.

 

You've just filmed a full 100' roll of film in your Bolex. Lo and behold, the film is now all on the bottom take-up reel. Before sending the film off for processing, do you have to re-wind the film back on to the top reel, in-camera (with shutter closed and lens caps on etc. and motor disengaged - I have a re-winding lever btw). Or do you simply pop out the full bottom reel, in semi-darkness of course, put it back in light-proof box, and post off for processing? I last filmed in 16mm in 1983 and can't remember what to do! Nearly everything I did was on Super 8. Thanks for your help.


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#25 Jean-Louis Seguin

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Posted 05 November 2017 - 09:09 PM

The answer is pop out the full bottom reel, in semi-darkness of course, put it back in light-proof box, and post off for processing.
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#26 Jon O'Brien

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Posted 06 November 2017 - 06:38 AM

Thank you, Jean-Louis.

 

Well, I have finally done some filming on the Bolex - my first for years. It was tough at first. You know what, I was sweating. Trying to concentrate, work out f-stop, focus, etc., all while discussing various topics with my subject, and trying to remain an affable filmmaker. At one point got so flustered trying to catch the light in time (we were in a rapidly changing light situation, with huge ominous clouds billowing across like something out of Ryan's Daughter) that I forgot in one or two shots to focus at the most open stop (at least, I think I forgot - will have to wait and see). The tripod I was using was slow to use. Anyway, on the whole it was good.

 

However ....

 

Got home, and noticed that the Sekonic L398A light meter ISO dial was now set on two clicks slower film speed than what I'd set it on when beginning filming (it was supposed to be set on 32 ASA to reflect the 2/3 stop difference when using reflex Bolexes). So at least some of the later shots are going to be 2/3 stop, or maybe a full stop, over exposed. At least that's better than under exposed. This was with Kodak 50D.

 

Realised that the ISO dial on my light meter rotates *way* too easily. I hadn't put it on a lanyard yet and was stuffing it quickly in and out of my pocket and this must have turned the dial inadvertently. Blast!

 

The dial turns too easily. It is easily moved with just the slightest sideways pressure.  Using it, I will have to check the ISO dial every single exposure. What a drag. I wonder if I should send it back.

 

Anyway, hopefully we got some nice shots.


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#27 Dom Jaeger

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Posted 06 November 2017 - 08:55 AM

Well done Jon for breaking the ice!

Don't worry about the overexposure, accidents are where you learn where the limits are! :)
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#28 Jon O'Brien

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Posted 06 November 2017 - 05:08 PM

Thanks Dom! Yes, I was on a steep learning curve, but I really did learn so that's great. By the end of the reel I was feeling I was getting my sea legs back.


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#29 Jon O'Brien

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Posted 06 November 2017 - 07:35 PM

Some initial post-event determinations.

 

Wind-up can be a drag when you are a filmmaker who likes to grab quick opportunities. Made more so by the use of a turret, requiring moving of turret or frustrating use of short wind lever. A tripod that requires levelling by adjusting the legs is another problem.

 

If I were to get more serious with this, I think I might need an electric motor and battery and a big tripod with 100mm or 150mm bowl, quick levelling, and baby legs as well. I'm thinking that rental options are looking more and more attractive. Why muck around? I'm not criticizing the Bolex, but just seeing that for best results you possibly need to think of different gear.


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#30 Simon Wyss

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Posted 07 November 2017 - 03:41 AM

A flexible shaft with a LH M5 thread at the end can help. You screw it in where the winding crank is, an assistant can take care of rewinding the spring, no matter in which position the turret is. No electricity needed, perhaps an additional Earl-of-Sandwich bread for the hand. Do invest in a tripod with bowl and bubble level on the head!


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#31 Gregg MacPherson

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Posted 07 November 2017 - 03:54 AM

Some initial post-event determinations.

 

 

 

I don't think one can get the sense of oneself, the medium or the equipment after shooting one 100' roll.  You don't need to carry the weight of this learning experience on your own. Join with some other film makers, help them in the execution of some small project, learn more quickly and make some contacts with people who will be useful later.


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#32 Doug Palmer

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Posted 07 November 2017 - 04:42 AM

A flexible shaft with a LH M5 thread at the end can help. You screw it in where the winding crank is, an assistant can take care of rewinding the spring, no matter in which position the turret is. No electricity needed, perhaps an additional Earl-of-Sandwich bread for the hand. Do invest in a tripod with bowl and bubble level on the head!

Interesting idea !  In theory perhaps one could wind up the camera even during a take ?  Assuming you don't disturb the camera. The main drawback with Bolex is the short-duration spring.  And old cameras tend to slow down after 20 seconds as well.


Edited by Doug Palmer, 07 November 2017 - 04:43 AM.

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#33 Simon Wyss

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Posted 07 November 2017 - 08:35 AM

Only with an older H camera can you rewind during run. The flexible shaft is attached to the spring core (also LH M5 thread), there is a slotted cap in the housing that you remove beforehand. I have done this, the camera had the winding key. Worked not bad. But frankly, many other cameras have a going barrel as well or a different system that allows to crank besides the spring, Bell & Howell Filmo 70s for example.

 

I have two younger H cameras here from which I have removed the spring stop intermediate gear. I can tighten the spring further and let it run all the way down, gets me around 55 seconds at sound speed. The danger of overtightening is always there.

 

The subject touches an interesting aspect of the H cameras, namely their development through time. Paillard omitted the going barrel after about 12 years. Again many years later the housing was given a big base for the weights and forces then added to the camera by zoom lenses, electric motors, and magazine. At that moment the old rewind-during-a-take feature could or should have been reintroduced. Alas, the thinking of the sixties was so different from the thirties’ groove that the half-forgotten possibilities were abandonded altogether. For the specialists as they were perceived when JFK was president the critical focuser was retained, silently. I had and still have contact with Paillard-Bolex employees, believe me, the rackover system and extended use of the spring was always smiled at by them. It’s a pity.


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#34 Jon O'Brien

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Posted 07 November 2017 - 08:32 PM

At this stage, short duration spring is fine, so definitely will see if I can find one of those flexible shaft winders - they sound just the ticket. That and a quick-level tripod would make a big difference.

 

Processing will be in Sydney (Neglab) and am sending off today.

 

Gregg, your comments are wise. I will give myself some leeway and not have my hopes up too high for my first reel. I will also look around for film people, but here, digital is king amongst those interested in filmmaking, and I've already been told by four locals and near-locals that movie film is 1. "old school", 2. "It's all digital now, film is pretty much finished", 3. "Oh ....  (confused vibe latent in the air) .. (laugh) ... you're doing things the hard way"; and " (smirk) Oh Jon, why don't you throw that old dinosaur in the bin and buy a real digital camera (or words to that effect)". Sigh.

 

It's all good. I'm not an iconoclast, or trying to be different, but am doing this because I genuinely really only want to shoot on film - and I was always like that - I always felt strongly about it. I'm enjoying being the only real film guy, that I know of anyway, around these parts. If there are any others in the Brisbane/SEQ region who would like to contact, feel free to join cinematography.com if you haven't already and send me a PM.

 

Plus, another update, the company I work for has indicated I could possibly be involved in some digital film production, so you see, looks like I might be getting acquainted with digital.


Edited by Jon O'Brien, 07 November 2017 - 08:38 PM.

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#35 Simon Wyss

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Posted 08 November 2017 - 02:35 AM

You are very much in touch with film, the rolling-loop movement was invented by Peter Ronald Wright Jones who had his shop on Beatty Road in Brisbane, Queensland. Could be an adventure to dig out his story before IMAX bought the patent from him. He collaborated with J. H. Hood of the Royal Brisbane Hospital, Herston, Department of Surgery, Sub-department of Radiology, in the early 1960s.


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