Arriflex BL-16 Question

[FilmUnited]

Does anyone know if there is a f-stop compensation when you use a monitor for video-assist on the Arri-BL 16mm? There is no info in the ASC manual concerning this and I have been unable to find it online.

I have noticed that when the video assist is hooked up, if the shutter is closed, the monitor goes black, and I have to frame advance to see again. Thus, I assume that the video assist signal is coming from light that is entering the gate or at least passing the shutter. I was worried perhaps some of this light was siphoned off to the external monitor, perhaps creating a 1/3 to 2/3 stop gap.

Can someone explain to me how the system works?

Thanks,

Corey

 

[ramdop]

hi

tha video assist is a small cam that see the image from the shutter of the cam (like the finder) so you can see an image only when the shutter is closed.
so no compesation needed.

and thats why you need to get the shutter in the closed position in order to see
ram

 

[scubba]

?? does that make sense?
when the shutter is closed the mirrored side of the shutter should cause the light to strike the cam of the video assist and thus show an image. but in this case it does not therefore it might be possible that the cam is actually not in the pathway of the eyepiece but somewhere behind it where no light hits the cam when the shutter is closed.
unfortunately the BL16 is not my turf at all

 

[Kevin_Zanit]

This is an odd issue.

The camera just uses a standard rotating mirror. The actual split is from the eyepiece (it is dimmer when you use a video assist).

It should only be getting black when the shutter is OPEN.

The way this system normally works is this:

As we all know, when the shutter is open light goes to film, when shutter is closed it reflects into the viewing system. The video tap gets its image from a bell shaped shutter. It splits to the eyepiece, and to the video tap. You can get shutters that favor the eyepiece or the tap (as to how much light they get).

You may want to get your shutter checked out. I would just bring the camera in for service and see what is going on. I have never encountered this myself.


Kevin Zanit

 

[shoichi]

Re: Arriflex BL-16 Question

Your BL probably has a B&W CCD tap that flickers.
NEVER expect to see your lighting from tap/ trust your incident/reflected reading.

Tap for film cameras are for framing/composition/camera move/continuity references, not for exposure.