I recently had some e-correspondence with Derrick Whitehouse regarding CP-16's and I thought the group might be interested in his comments on some issues which have come up on the list.
Derrick says that you can drive the camera with 18V but you should not use 24V.
Regarding shutters, he had several interesting comments.
The three flavors of shutters are 156 degree bowtie, 144 degree bowtie, and 170 degree half-moon. According to Derrick, the smearing of highlights in certain conditions with the bowtie shutter is a design issue, not a maintainence issue. The 144 degree shutter is less prone so smearing than 156 degree. In any case, the conditions he described under which it can be observed:
-- lens wide open
-- lens at wide angle
-- highlights in the top right or left hand corners.
Half moon shutters were built into cameras sn 1995 and up. Bowtie shutters are not upgradable to half-moon.
I would be interested in any other points of view on these items. (Jeff K.??)
Mark Schlicher Sunporch Entertainment
>I would be interested in any other points of view on these items. >(Jeff K.??)
Derrick Whitehouse is a good friend of mine and the ace CP repair person. I agree with his statements fully. For CP repairs (and Steadicam sales, and everything else) he is highly recommended. Ken Hale, his lens guy, is also excellent and affordable.
However, I personally don't love the CP16R, I like the non-reflex CP. (Not with a zoom, but with a 10mm Switar and a custom optical finder.) Great camera, none of the shutter problems mentioned re the reflex, lighter, quieter. But that's a specialist opinion.
>Derrick says that you can drive the camera with 18V but you should >not use 24V.
But given how inexpensive and convenient the CP onboard batteries are, I can't imagine why anyone would want to use an external battery, except in an emergency. CP originated the onboard battery, a great and important feature. Who wants to wear a battery belt???!!
Jeff "CPs are fine, though I also own Aatons" Kreines
For my 2 cents, as a CP owner, I've liked my CP. It's a CP16 Reflex (the mirror, not an Angeniuex with the prism.) with a video prism and the half moon shutter. It's great for hand held because its light. I like to use an external battery because the on boards tend to die too quickly for my liking.
As far as the shutter goes, do not get a butterfly shutter of any kind! They suck! If you do do a sunset with a CP with a butteryfly shutter you will get a massive streak of light across the picture in every frame. Not good.
As far as 18v vs 24v, I've been using a 24volt block which I built for $150.00 US. Its top output is 26v and it lasts for weeks between charges, probably because the CP doesn't use much amperage. If your going to built a battery, make sure you use Lead Acid cells and 3 pin XLR connectors, that way you can use a Panavision battery in a pinch. I've also bolted a left side bracket on the CP so I can use the pan handle off a Oconnor 1030 head.
I am curious though, Jeff, why Derrick says not to use 24v. The manual which I have for my body says I can go up to 27v. <:-0
One question: Can you shoot a 24 fps shot of an LCD monitor without using a TV sync box? Any permutations on said question is appreciated?
Jeff Kreines writes :
>CP originated the onboard battery, a great and important feature. Who wants to wear >a battery belt???!!
Until today I thought that was the Aaton7, Photokina September 1972.
JP writes, with melancholy:
>CP originated the onboard battery, a great and important feature. Who wants to wear >a battery belt???!! Until today I thought that was the Aaton7, Photokina September >1972.
Don't feel too bad. There are enough pioneering features on the Aaton to last and last! The CP was essentially the ultimate Auricon conversion. Not a bad thing, but evolutionary not revolutionary.
I believe I saw the prototype CP16 (different handgrip -- non-adjustable, and Auricon centerplate) in late 1970 at Victor Duncan in Chicago.
Yes, there were earlier cameras with batteries attached, but I am limiting this to shoulder-held sync cameras. The Maysles brothers' "bazooka" camera had one, albeit huge and clumsy, and Pennebaker worked on it after a famous incident at the Monterey pop festival, where someone gave him some wine laced with acid and he forgot he was wearing a battery belt and that it was attached to his camera, which soon ended up on the floor. (If you look at the stills of him there, you see his handgrip -- the little Arri plastic grip -- is broken off the camera. Pennebaker was the first to put a handgrip on the front of the camera for shoulder-held use, a great invention!) Anyway, the lens was also knocked off, and Jimi Hendrix was on in an hour. Thank god for the portable Richter collimator... or Hendrix's amazing Wild Thing (w/flaming guitar) might not have been captured in focus...
Jeff "tell me another war story, Grampa Pennebaker" Kreines
>For my 2 cents, as a CP owner, I've liked my CP. It's a CP16 Reflex (the mirror, not >an Angeniuex with the prism.) with a video prism and the half moon shutter. It's great >for hand held because its light.
Really? I get 3600-4000 feet per charge on my non-reflex, I'd imagine a good battery would get 2800 feet on a reflex.
>As far as the shutter goes, do not get a butterfly shutter of any kind! They suck! If you >do do a sunset with a CP with a butteryfly shutter you will get a massive streak of light >across the picture in every frame.
That is lens dependent, and not an accurate statement. Fast lenses with a big cone of light (most notoriously the 28mm f/1.1 Angenieux) will have that problem. You might have had a shutter timing error.
>I am curious though, Jeff, why Derrick says not to use 24v. The manual which I have >for my body says I can go up to 27v. <:-0
Ask Derrick! Me, I only use the factory batteries with the CP. It's my 35BL I use weird batteries with!
Could anyone please tell me, assuming the CP is running up to specs, if there is a huge difference made by shooting on a non-pin camera like the CP? Also, does anyone know a nice way to check the gate on the CP without having to physically push the mirror out of the way? I know on the SR's you can just hit the test button and the mirror will swing around for one frame.
Thanks very much,
Actually I feel the BL-mag is very simple to load, and certainly if you are shooting double system, then the BL is a hell of a lot easier to thread than the CP. Hand-holdability is a good point to consider. As for checking the Gate.
DO NOT PUSH THE MIRROR. Think about it.
You are often times focusing off of the image reflected by the mirror. Push the mirror and you risk moving it out of the proper position, maybe adding a feew thousands of an inch to your ground glass distance ( although the lens to film plane distance wouldn't be affected), making eye focusing un-reliable. Of course you might just push the mirror hard enough to make it go out of timing with the mechanism.
The mirror is meant to be driven by the Camera, it is not meant to drive the entire camera mechanism. Of course these just might be me being extremely over cautious. The lack of an external inching knob is a pain. Run the take 2 to 3 seconds longer than the take. This should get the film into the mag. ( might need five seconds), and then open the camera door, and use the internal inching knob.
Registration, A well maintained camera will produce steady images. Registration pin or no. However the C.P.16 has a claw that enters the film in a curved rather than straight in manner. Whether or not this is a registration problem, I don't know. Are you doing double exposing Matte passes? The best way to check the registration is to shoot a Registration test. My personal experience with the C.P.16 has lead me to the decision that every so often, check that the loop hasn't been lost, and never never start/stop the camera. Once I turn the camera on, I let it run for at least 5 seconds before stopping it. However most of my experience with CP16's were from College owned and maintained cameras.
In general, registration does not get overly critical until you have something to compare it with. For example, if you're doing superimpositions of titles over a distant mountain background scene, you might see some unsteadiness with non-pin-registered cameras. On the other hand, if there is no comparison reference, you would have to be pretty unsteady before anyone noticed. Arri 16's, Eclairs, and Aatons have a pilot pin registration which is not a true registration pin like on a Mitchell or a Maurer. Whether the pilot pin is actually effective is the subject of some debate, because the pin has a bit of slop around it and does not "jam" the film into position like a true registration pin. At the risk of opening up a major debate, I'd venture to say the the spring loaded gate of a CP-16 probably gives one as much image stability as a pilot pin. The mirror shutter on a CP-16R has a cycling circuit that brings the mirror into viewing position and closes the shutter...hopefully preventing flash frames. If that no longer works or you're shooting with a CP-16 non-reflex, use the main shaft inching knob inside the camera to rotate the mechanism. Don't want to fog the film inside the camera?....move the shutter carefully with your finger.
Knock on wood, my CP-16R has not lost its loop on me, but I must add that Paul at Whitehouse did a superb overhaul on the camera (can you say ten cans of film on one battery charge? Now that's a smooth-running movement!) Has your client had an overhaul? FWIW, I thread the top loop so it looks just like the threading diagram and I have followed the Sylvia Carlson book's recommendation of 1/4" clearance (when running) at the bottom. It seems like this approach results in a very specific number of perfs in the loop, but I've never counted. I'll try to remember to mark and count the perfs next time I do a scratch test. Unlike Jeff, I don't skip the bottom rollers, just timid I guess...
Page 355 'The Professional Cameraman's Handbook' /Verne and Sylvia Carlson: "Adjust film so that lower loop clears bottom of camera by 0.31cm (1/8 in)." "...........and I have followed the Sylvia Carlson book's recommendation of 1/4" clearance (when running) at the bottom."