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Bolex H16 Newbie needs exposure help !


Rene Mühlberger

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Hello! I´m new to this forum and it´s a pleasure to be here!

I´m not a pro (sorry!) , but I film my own music videos (because I´m a pro musician, haha). Mostly shooting with my BMPCC - but recently with my serviced (and gate widened) Beaulieu 4008. 

Last week I went crazy and bought a Bolex SBM with Kern 16-100 lens. WUHU! 

Planning to shoot my first test roll (bright sunlight, Kodak 50D) - BUT, I don't have any clue HOT TO EXPOSE CORRECTLY with this camera. 

The build in lens light meter doesn't work anymore. SO, could u please please help me out here? 

 

-Is the only way to expose with the F-Stop wheel ? (Or, does changing the ISO on the lens actually do something to the aperture or shutter speed? my guess I no) 

-What kind of Lightmeter do I need? Or App? 

-On the beaulieu I basically filmed almost every scene with fully opened aperture (1.8). Also Kodak 50D. That worked so well ! Could that work here too? 

 

SO, generally speaking, I need a lot of help with getting started... please please help ! 

Any advice is extremely appreciated !!! 

(I will/can post results of the Beaulieu shooting if you want. It looks terrific imho)

 

THANKS, René from Vienna 

 

 

 

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Hi René,

congrats on your camera!

First thing would be to get hold of a manual:

http://www.vintagecameras.fr/images/MonSite/BOLEX/H16_Reflex/_Doc/H16_SBM_Manuel_en.pdf

If you have some old dummy film, practice loading and checking how the film runs through the gate. Set the eyepiece focus to your eye as described. There are lots of threads on this site about Bolex filming, google any questions with 'site:cinematography.com' in the question, or start another thread here if you can't find answers.

You'll need some sort of light meter, but I don't know about light meter apps, sorry. Your main variables are the filming speed (ie 24 fps), the film ISO and the lens aperture. You can also vary the shutter angle, but maybe leave that option for later.  If you're filming at 24 fps, the actual exposure time is 1/65 sec. But to compensate for the light that is lost to the reflex viewfinder, you need to add about a third of a stop of light, so the "adapted" exposure that you will set your meter to is 1/80 sec. So all you need to do is set your meter to the film ISO and 1/80 sec (if filming at 24 fps). There is a table of actual and adapted exposure times for different filming speeds in the manual.

If you get a meter that has 'cine mode' you can use a different method. Set the meter to your filming speed (say 24 fps) and then compensate the ISO setting. Because cine mode assumes a 180 degree shutter while your Bolex is only around 133 degrees you need to compensate another third of a stop on top of the viewfinder light loss, so a total of two stops. For 50 ISO film you would set the meter 2/3 stop slower, to 32 ISO. 

Here is a manual for the 16-100:

http://www.vintagecameras.fr/images/MonSite/BOLEX/H16_Reflex/_Doc/Vario-Switar_100-POE.pdf

It tells you how to manually set the aperture. 

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Thanks so much Dom! It´s great to get such a well written advice - especially since I became really frustrated when I got the camera - finding out that the exposure meter is broken - and the Lens is not as wide as I expected. 

Anyway, I am happy to say that all the stuff u wrote is clear to me now - since I googled and googled for days - but your summing up makes it feel like I do actually know now. 

What I still don't get: How could I stop down 1/3 or 2/3 stops on the camera? I thought stopping down 1 stop means from one figure to the next (like 5,6 to 8). There are no spots in between - so what do I get wrong here? 

I guess I´m gonna buy an sekonic l 398 light meter. Looks good and vintage - I love that!  

Would u know if a used old one is also okay? I mean, do they wear out? 

Final question could be: Is the 50D maybe so "lowlight" that I would just go out and shoot a test roll with aperture fully opened? It worked on my Beaulieu 4008 on a summer day with 3 rolls. The exposure needle was in the right zone the whole day. I know it would be kinda dumb - but I don't know if I can get a lightmeter that fast - I really should shoot the testroll in the next days... 

HEY; thanks so much! This forum kicks ass! I´m also into old VW´s and those forums are great too! I´ll keep it pre-1980 with my gear. Love vintage mechanic that much! SO reliable ! 

CIAO, René 

 

ps: if ANYONE sells a switar 10mm RX I would happily buy it. 

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AH, one more... 

Does anybody if the ASA setting on the KERN 16-100 changes the aperture / OR: what does it technically change? 

Does it only give information to the build in light meter - or does it actually do something to the lens or aperture as well in manual diaphragm mode? 

(OR: Do I have to adjust it to the film speed when I expose manually - or not?) 

THX 

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6 hours ago, Rene Mühlberger said:

What I still don't get: How could I stop down 1/3 or 2/3 stops on the camera? I thought stopping down 1 stop means from one figure to the next (like 5,6 to 8). There are no spots in between - so what do I get wrong here? 

I guess I´m gonna buy an sekonic l 398 light meter. Looks good and vintage - I love that!  

Would u know if a used old one is also okay? I mean, do they wear out? 

Final question could be: Is the 50D maybe so "lowlight" that I would just go out and shoot a test roll with aperture fully opened? It worked on my Beaulieu 4008 on a summer day with 3 rolls. The exposure needle was in the right zone the whole day. I know it would be kinda dumb - but I don't know if I can get a lightmeter that fast - I really should shoot the testroll in the next days... 

Yeah those zooms don’t have intervals between their aperture marks like most cine lenses do. I guess just use the closest whole stop, film is pretty forgiving. Maybe err on overexposing rather than under.  I think those zooms were designed to be used primarily in auto-aperture mode, where the iris can just float between stops. 

I don’t know enough about Sekonic meters to give advice, but plenty of people have used old ones. There are threads in the forums here about them, and metering in general.

Beaulieu 4008 cameras have a shutter angle of 100 degrees, so if you were filming at 24 fps the exposure time would be close to the ‘adjusted’ Bolex exposure time of 1/80 sec. In that case you should get similar results. If you were filming at 18 fps it would be about a third of a stop brighter than the Bolex would be at 24 fps, which isn’t that much really.

6 hours ago, Rene Mühlberger said:

AH, one more... 

Does anybody if the ASA setting on the KERN 16-100 changes the aperture / OR: what does it technically change? 

Does it only give information to the build in light meter - or does it actually do something to the lens or aperture as well in manual diaphragm mode? 

(OR: Do I have to adjust it to the film speed when I expose manually - or not?) 

THX 

The ASA setting on the lens is only for the auto-aperture, giving information to the built-in meter, it has no effect when you set the aperture manually.

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Hey Dom!

A big thank you! All questions answered ! I will look through the lightmetering posts and shoot my first testroll next week!

I went outside yesterday and tinkered around with the 16-100 lens....It looks awesome through the viewfinder. Not as bright as the Beaulieu 4008, but maybe 70 percent with aperture opened fully. Totally useable. (Not like the H8 I bought l....)

One thing that could still kill the film is that the TAKE UP SPOOL turns a little bit "wobbly" or "unsteady"  when I shoot (tested without film of course). It gets better after 1 sec. But I can pretty easily stop the spool with my finger. I hope that is normal.

Let´s see. The 50D is in the Fridge and it´s gonna be sunny in Vienna next week ! YEAH !

 

thanks again! this is a really great forum !

René

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