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mitchell vs. panavision registration


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#1 dan kessler

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Posted 07 September 2010 - 01:24 PM

I'm hoping for some authoritative feedback regarding the
registration pins in both of these systems.

I'm familiar with the specs and tolerances for BH perfs,
but I want to know if camera makers use these exact same
specs for the pins, or do they use something else, e.g.,
oversize?

Also, which pin is the full-fitting pin in Mitchells?

Do Panavision's dual full-fitting pins really give
superior registration? The Mitchell scheme adheres to
time-tested tool and die making principles, so I'm curious
if Panavision does have a better mousetrap.

Thanks.
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#2 John Sprung

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Posted 07 September 2010 - 03:01 PM

My sense of it is that they're really close to a wash, so much so that I've never had the issue arise. The deciding factor is usually that Panavision is in business, and the Mitchell company is long gone. So, Panavision or Arri is used as the "A" camera for production, and Mitchell maybe for background plates, if somebody has one.





-- J.S.
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#3 Robert Houllahan

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Posted 07 September 2010 - 03:29 PM

I was under the impression that the Mitchell movement was the basis for the Panavision cameras. I think a properly working Mitchell, Panavision or Arri pin reg movement will all be about the same as far as steadiness goes.

-Rob-
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#4 Simon Wyss

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Posted 08 September 2010 - 04:07 AM

Dan, the base lies within the concept of the Bell & Howell Standard Cinematograph Camera’s movement. All later attempts followed the idea of the tapered pins on which the film will be literally wedged, block dead.

Leonard, Mitchell, Wall, Kästner, everybody else starts from the film running in a lineal fashion contrary to the forth-and-back flying film with the BH shuttle gate. So they employ movable register pins with tapered tips. The full fitting pin is the one on the right side when you assume position behind the camera and view towards lens and scene. The other pin fits the perforation hole only vertically and leaves clearance for any film width variation due to shrinkage, warmth and or humidity expansion, and so on.

All cameras since Mitchell movement B (original Leonard movement “A” had fixed pilot pins) belong to the same class # 2. Class # 3 is reserved for film movements with rigid pins: Bell & Howell Standard, Leonard, Newman & Sinclair, Jones (rolling-loop device). Simple claw movements without additional means to steady the film are class # 1.
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#5 Marty Hamrick

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Posted 07 November 2010 - 10:01 PM

I was under the impression that the Mitchell movement was the basis for the Panavision cameras. I think a properly working Mitchell, Panavision or Arri pin reg movement will all be about the same as far as steadiness goes.

-Rob-

I was under the impression that Panavision bought out Mitchell and retained the movement design. I've never shot with a Panavision, but I have used Mitchells. The threading diagrams in the ASC manual look close to identical to me. I used a Mitchell 16 and 35 for lab work on opticals, titles, BG plates and even multi pass work. The registration was never an issue, dead on perfect every time.
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#6 Leo Anthony Vale

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Posted 11 November 2010 - 05:37 PM

I was under the impression that Panavision bought out Mitchell and retained the movement design. I've never shot with a Panavision, but I have used Mitchells. The threading diagrams in the ASC manual look close to identical to me. I used a Mitchell 16 and 35 for lab work on opticals, titles, BG plates and even multi pass work. The registration was never an issue, dead on perfect every time.


The Panavision PSR and R-200 were rehoused Mitchell NCs.

So the Panaflex movements would be slightly modified Mithell movements.
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#7 Stephen Williams

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Posted 12 November 2010 - 02:22 AM

The Panavision PSR and R-200 were rehoused Mitchell NCs.

So the Panaflex movements would be slightly modified Mithell movements.


From memory there was a strike at Mitchell over 10c an hour, Panavision then hired many of the Mitchell staff & Mitchell never recovered. I know David Stump has a Mitchell with 2 oversize pins, it's the steadiest camera he has ever seen! Panavision is trying to make a silent camera, the size of the pins will make a difference especially in the lighter cameras.
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#8 dan kessler

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Posted 12 November 2010 - 11:31 PM

Appreciate all the feedback so far. I knew about the Mitchell legacy
in Panavision cameras, but does anybody know the actual pin dimensions
and tolerances?

I suppose I could rent a camera, take it apart and mic the pins, but
I thought I'd ask around first. :)
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#9 Simon Wyss

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Posted 13 November 2010 - 12:34 PM

The pins are tapered and a snug fit is adjusted in a camera’s assembly. Theory is nice but practice is heiss.
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#10 dan kessler

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Posted 13 November 2010 - 01:49 PM

I understand, Simon, but a snug fit to what gauge?

Here's what I'm driving at. I once made some registration pins
using #35 drill blanks. The blanks have a nominal diameter
of .1100, with a tolerance of +0000 -.0002. I ground the flats
to match the nominal BH perf height of .0730, using the same
tolerances. So, these were definitely within print specs for
BH perfs, but how do they compare to a Mitchell or Panavision?

Do they gauge to the upside, say +.0002 -0000, or something else?
Do they start with a larger nominal size, smaller, what?

They have to have a gauge, something they consider to be their standard.

Surely they don't just grab any old piece of film and stick it on.
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#11 Stephen Williams

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Posted 13 November 2010 - 04:33 PM

Somewhere at home I have some Mitchell movement spare parts, including 2 pins. I am away on a shoot for a week but hopefully I can find then & take some measurements when I get home.
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#12 dan kessler

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Posted 13 November 2010 - 06:32 PM

Well, that's more trouble than I would've asked for,
but if you do get the chance, that would be awesome.
Thanks, Stephen.
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#13 Simon Wyss

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Posted 14 November 2010 - 02:38 AM

Let me now suggest you read the following tutorial paper.

Pin Registration by A. C. Robertson in JSMPTE, vol. 72, Feb. 1963, pp. 75 through 81
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#14 dan kessler

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Posted 19 November 2010 - 11:24 AM

Simon, just received and read that article you cited.
Very, very informative! Thanks!
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#15 Stephen Williams

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Posted 25 November 2010 - 09:02 AM

Big pin is 2.55mm (0.1") x 1.86mm (0.073") length x width
Small pin is 1.27mm (0.05") x 1.83mm (0.072")

so width is very under size, I have a parts manual somewhere I think the sizes are mentioned, if they are I will update.
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Gamma Ray Digital Inc

Wooden Camera

Glidecam

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Rig Wheels Passport

Abel Cine

Tai Audio

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Visual Products

Paralinx LLC

Willys Widgets

FJS International, LLC

Media Blackout - Custom Cables and AKS

Aerial Filmworks

Technodolly

CineLab

Metropolis Post

Ritter Battery