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Beaulieu 6008s Low Light Shutter Option.


Trevor Roach
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Hi there,

Just started getting into Super8 during the pandemic and bought myself a Beaulieu 6008s. Shot and got back my first roll, and was overall happy with it. Here's some stills for fun:

https://imgur.com/a/w7vM3Ft

Upon re-reading the manual, I noticed the "Normal" setting at 24fps for the shutter angle is 1/96, as opposed to the LowLight mode which is 1/60. 

Any reason why 1/96 is considered normal? I was wondering why my footage looked a little darker than I was metering (luckily I was trying to shoot a stop over when I could). Seems like for 24fps it'd be much more natural to have the shutter at the 1/60. 

Thanks.

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The 1/96th of a second shutter speed is considered "normal" on the BEAULIEU 6008S due to the design of the oscillating guillotine shutter....which moves up and down, rather than of a circular design as are most movie camera shutters.  In the circular shutter design, the shutter speed per frame is determined by the 'pie' slice wedge opening angle as well as the rotation speed (frames per second)......on the BEAULIEU, the math just works out in their design to be 1/96th per second, as that is their standard setting.  In the LL setting, the did a modification on their shutter to allow  a bit more light to enter, albeit some limitations for use as per the Instruction Manual's details, NO fading allowed at this setting!

   So, yes, in lets in more light....but a true XL (existing low light) camera it isn't, compared to other XL Super 8mm cameras.  Among those, the pie/wedge slice opening [albeit the shutter angle opening] is much larger than the normal range of 130 to 180 degree range....and is anywhere from 190 to 230 degree opening, depending on the make of camera.  Those truly allow nearly a full stop of more light to expose each frame.  Typically anywhere from 1/20th to 1/40th of a second per frame, depending on if you're shooting at either 18fps or 24fps.   Unless I need to smooth out some motion movement, I only film with Super 8mm at the original design intention of 18fps, which is fine. Filming and projecting/transferring at 24fps offers only a slight quality improvement, is harder on the film itself, eats up film faster at 2.5 minutes per cartridge versus 3min 20 sec at 18fps.

    A smaller shutter angle, either due to increased filming rate of actual shutter angle, will allow less motion blur per frame; this can be helpful or visually disturbing either way, depending on what is being filmed and how you want the 'look' to be.  BEAULIEU cameras have been known for very sharp images, due to their frame registration/transport, significantly higher shutter speed per frame due to their shutter design, and those terrific lenses.  However, this comes at a price for these cameras not really being useful for very low light conditions (unless you film at a very slow frame rate, allow a longer shutter time duration per frame....best done on their silent models or the NIZO or BAUER cameras with their special options for longer exposure per frame).

   As for your footage being darker, that shouldn't be the case just because of the shorter exposure per frame, unless you're filming in a light level too low for the film to record.  As long as the camera's exposure metering system is working correctly, and you have set the film speed on the ASA/ISO knob correctly, the exposure should be fine.  To double check, compare the camera's metering to an accurate light meter and meter several objects light and dark as well as an 18% gray reflection card.  Compare readings. If the camera is off a bit, you could just adjust the ASA/ISO knob to compensate to 'lighten' up your images. 

Hope this helps!

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Hi Martin,

Amazing. Thank you so much for the detailed response. I forgot to mention when I was metering, I was using my external light meter, rather than the one in-camera. Some of those scenes I was getting a 2 or 1.4 for my key, so I was already wide open, but wasn't aware I was nearly a stop different in camera because the shutter! 

I'm treating my Super8 shooting as a way to practice with film during the pandemic, so shooting at 24fps is my go-to. Regarding fading, I'm not currently interested in using that, though the feature is cool! I'll give the 1/60 shutter a chance next week and see if I like it better. 

Beyond the lack of fading, and additional motion blur, are there any other downsides to shooting entirely in LL mode? Is the sharpness drastically different? 

Thank you again for the detailed and timely response! 

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  • 6 months later...

Also found this in a white paper written by @Michael Lehnert

Beaulieu is known for being the only manufacturer to incorporate mirror reflex shutter systems in Super 8 cameras. Normally, Super 8 cameras use a beamsplitter or prism of varying optical quality that diverts 75% of the incoming light onto the film and 25% into the viewfinder. Obviously, that approach somewhat compromises both usages, especially under bad light conditions. Beaulieu's unique patent solution is a typically French invention: a guillotine (up and down) shutter with a 45° mirror that – as Beaulieu brochures proclaim like a mantra – lets alternatingly 100% light onto the film and 100% light into the viewfinder. Due to the required timing of the alternating phases of the guillotine shutter, the maximum exposure time at 24 fps is 1 /86 sec ( 1 /87 sec for 25 fps). As this is shorter than in most other Super 8 cameras, the shorter exposure time gives the impression of producing sharper pictures: motions do look more accentuated and static shots much crisper. In effect, the guillotine shutter leads to a higher fidelity reproduction of what is being filmed for both the viewer in presentations and the camera operator on location.

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Did some more research over the weekend and calculated the following, which could help you set your light meter:

Beaulieu X008 Cameras have the equivalent shutter angle of 100° in normal mode and 144° in LL mode.

On other cameras, once we factor in the 0.75 transmittance due to the beam splitter, the calculated shutter angle would range from 142.5° to 172.5°.

I was interested in doing this exercise to understand whether Low Light super-8 cameras could bring in more light to the film than other film cameras with a max shutter opening of 180° like my 16SR3, but it appears they don't. 

That is, if I didn't f*ck anything up in my spreadsheets, ahem. 😅

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Here's what the Beaulieu guillotine shutter looks like (this is from a 4008):

1682034522_Beaulieu4008shutter.jpg.45ea64448681b560ba15e2433c7d7683.jpg

In the camera the shutter is aligned vertically, left side of the photo is camera bottom.

The gap between the two segments of the variable shutter can be made smaller until it closes. There is a secondary shutter behind the variable segments, which ensures the sliding gap only exposes the film in one direction.  I'm not sure exactly how the 6008 low light mode works, but presumably the gap is widened to the limit of still covering the pulldown phase.

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