mitchell vs. panavision registration

[dan kessler]

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.

[John Sprung]

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.

[Robert Houllahan]

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-

[Simon Wyss]

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.

[Marty Hamrick]

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.

[Leo Anthony Vale]

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.

[Stephen Williams]

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.

[dan kessler]

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. :)

[Simon Wyss]

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

[dan kessler]

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.

[Stephen Williams]

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.

[dan kessler]

Well, that's more trouble than I would've asked for,

but if you do get the chance, that would be awesome.

Thanks, Stephen.

[Simon Wyss]

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

[dan kessler]

Simon, just received and read that article you cited.

Very, very informative! Thanks!

[Stephen Williams]

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.