Bolex P1 ZOOM REFLEX Daylight filter

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supa8
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Bolex P1 ZOOM REFLEX Daylight filter

Post by supa8 » Fri Apr 13, 2012 10:12 pm

Hi
Does this camera have a built in daylight filter?
I'm planning to shoot 100D on it, so would like to make sure there is no daylight filter set on it.
Anyone has any experience with this baby?

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sciolist
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Re: Bolex P1 ZOOM REFLEX Daylight filter

Post by sciolist » Fri Apr 13, 2012 10:36 pm

No, there is no built-in filter. A daylight filter fitting the two-part lens hood was usually supplied.

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MIKI-814
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Re: Bolex P1 ZOOM REFLEX Daylight filter

Post by MIKI-814 » Sat Apr 14, 2012 6:02 pm

Only Super8 cameras had the built-in filter and this is Normal 8

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beamascope
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Re: Bolex P1 ZOOM REFLEX Daylight filter

Post by beamascope » Sat Apr 14, 2012 6:23 pm

Actually the Yashica 8E III had a built in daylight filter and ND filter. I would guess other might have as well but they certainly were not auto set by a notch like in super cameras you had to dial the Yashicas into place. They are right though about this camera it has no built in filter. This might help as you might need to use the fancy shutter option to get correct exposure.

http://www.bolexcollector.com/cameras/p1.html


Here is the yashica if you care.

http://camarasclassicas.blogspot.com/20 ... -eiii.html

supa8
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Re: Bolex P1 ZOOM REFLEX Daylight filter

Post by supa8 » Sun Apr 15, 2012 12:42 pm

ok thanks.
So if say you were going to use an iphone app for metering, would you also need to compensate for the fact that you lose 1 fstop through the viewfinder/lens? I've heard this is the case with 16mm and super8 cameras if you meter separately, but not too sure why.
Apparently, the effective shutter speed for the p1 is 1/38th at 16fps and 1/43rd at 18fps. That said, according to a shutter speed calculator, with a shutter angle of 165 degrees, the shutter speed at 16fps is supposed to be 1/34.5 (and 1/39th @18fps)
I understand the shutter speed depends on the shutter angle on the camera and the frame rate you choose.
The P1 has an Adjustable dial changes the shutter opening from 0-165 degrees to allow for shortened exposure times and fades, so I take it the regular shutter angle on this camera is 165 degrees.

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beamascope
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Re: Bolex P1 ZOOM REFLEX Daylight filter

Post by beamascope » Sun Apr 15, 2012 5:50 pm

As far as the viewfinder you'll want your eye up against it or to have it covered when shooting so light does not leak in through it. Since it is a reflex camera light entering the eyepiece can effect exposure. I've never heard of allowing for it as far as separate metering goes. You might be thinking of allowing for filters ON the lens itself if you are metering separately. Filters have a "filter factor" that must be considered when using them. If you were metering through the lens the camera would simply open up more due to the filter being on the lens. With external metering you must do the compensating.

This might help...or hurt your head. :D

http://www.tiffen.com/camera_filters.htm

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BAC
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Re: Bolex P1 ZOOM REFLEX Daylight filter

Post by BAC » Sun Apr 15, 2012 10:42 pm

When I shoot with my P1 and P2 I don't make any compensation for the light lost in the view finder and the film comes out with good exposure. I have also used an i-phone app for metering with these cameras as well with great results.

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cameratech
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Re: Bolex P1 ZOOM REFLEX Daylight filter

Post by cameratech » Wed Apr 18, 2012 6:14 pm

supa8 wrote:ok thanks.
So if say you were going to use an iphone app for metering, would you also need to compensate for the fact that you lose 1 fstop through the viewfinder/lens? I've heard this is the case with 16mm and super8 cameras if you meter separately, but not too sure why.
Apparently, the effective shutter speed for the p1 is 1/38th at 16fps and 1/43rd at 18fps. That said, according to a shutter speed calculator, with a shutter angle of 165 degrees, the shutter speed at 16fps is supposed to be 1/34.5 (and 1/39th @18fps)
Any reflex viewfinder system that uses a prism or a pellicle to divert some of the light to your eye (like most reflex amateur cameras) is taking away light from the film, so you should compensate for it. On a reflex H16 for example the prism diverts something like a quarter of the light, about 1/3 stop. I don't know how much exactly the Pan-Cinor viewfinder prism diverts, or whether the printed shutter speeds are accounting for it. The difference between 1/38 and 1/34.5 is only about 10% which seems pretty small, but maybe that's all it diverts. It's annoying, but hardly any manuals make mention of this.

But there's also the issue of the aperture being marked in geometric f-stops. The zoom itself loses light at each air-to-glass surface, so the actual transmitted light (measured as a T-stop) could be 1/2 to 2/3 stop less, at least for an old zoom with primitive coatings (the P1 came out in 1961). So I'd probably open up 2/3 stop with an external meter.
Dom Jaeger
Camera/lens technician
Cameraquip, Melbourne

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