Movie Tech 1: The Panaflex Camera, it shot Star Wars and Raiders and more.

[blip]

Thought I might try a thread or two about the practical side of movies, in short the technology behind it all.
I figure that people who build props are hands on people who invariably want to pull things apart and see how they work.
So hopefully gearheads like yourselves will enjoy a little chat about the strange black boxes that capture magic onto film.

Might as well start by throwing the movement of the Panaflex (the camera that Star Wars was shot on) in front of you.
Who made it? Why? Where? What does it do? How does it do it? And why does it need to do it that way?
(I'm no expert on this topic, just interested, so if you have any additional information, I'm all ears.)
　

 

[JediG60racer]

Re: Movie Technology for Gearheads.1: The Panaflex. Camera

More importantly, can you make a lightsaber or any props out of it?

 

[blip]

Re: Movie Technology for Gearheads.1: The Panaflex. Camera

Good point, I don't think any film person would dare touch one of these drives.
you can't even buy them, they were leased only.

But I might do a followup tread on the VistaVision cameras that ILM got at a discount to put on the Motion Control rigs.

Ps: I've sent a memo out to every Panavision shop to check your pockets before you leave the store.

 

[blip]

Re: Movie Technology for Gearheads.1: The Panaflex. Camera

 

[Apollo]

Re: Movie Technology for Gearheads.1: The Panaflex. Camera

When you get to the Dykstra-Flex I'm there!

 

[blip]

Re: Movie Technology for Gearheads.1: The Panaflex. Camera

When you get to the Dykstra-Flex I'm there!

Oh yep, big fan of that rig.
I just need to cover the basics in this one first.

 

[vistaVision]

Re: Movie Technology for Gearheads.1: The Panaflex. Camera

I've worked extensively with all the camera systems you've mentioned (and many you've not) including Arri, Mitchell, Panavision, Wilcam and others, and also a lot with the "large format" cameras, including 65mm, Imax and, of course, vistaVision. I had a great "side job" for years taking care of all the Paramount vistaVision cameras, as well as occasional tech work for ILM (and other FX orgs) on their equipment.

What would you like to know about this old Panaflex?

Marcus

 

[blip]

Re: Movie Technology for Gearheads.1: The Panaflex. Camera

The best person to ask is the one doing it.

Wow! That would be a dream job.
Nothing like having a real expert to give the practical (rather than theoretical) way things are done.

The main point of these " Movie Technology" threads is to go over the basics and history of filmaking.

Iv'e got a hundred questions for you, but can only ask the ones that fit the point the thread is at now.

I'm wondering how the film is stopped for a moment while the shutter is opened? I know that if you open the shutter while the film is moving, the picture will be a blurr.

 

[vistaVision]

Re: Movie Technology for Gearheads.1: The Panaflex. Camera

A great question! The intermittent movement is what makes movies work!! You are correct, in (most) movie cameras the filmstock itself is "pulled" into position by the "movement" and held motionless for a brief moment in the "gate" while the exposure is made. Consider that this is done 24 times per second (or much faster, 300 fps or more in specialized cameras)! So how does that work? Well, it's all about the perfs (perforations) that you see running down both sides of the filmstock. These are very precision holes. The camera movement's "claw" pulls the filmstock, in a single stroke, the appropriate distance (35mm is usually 4 perfs, 65mm is 5 perfs, vistaVision is a whopping 8 perf "pulldown"). The claw moves on a cam and never stops moving, but does retract from the filmstock after pulling the film into place for a frame to be exposed. At the same moment the claw retracts, one or more "registration pins" engage the perf(s) to align the frame for the exposure. (Think about how a sewing machine, the original inspiration for a camera movement, works). The claw never stops moving, the pins never stop moving, the rotating shutter never stops moving, only the filmstock itself stops and starts and stops and starts (well, I'm sure you get it).

As for the shutter: It is never "opened" in the sense of a window opening or closing. The camera shutter is similar to a projector shutter, it rotates. Think of a circle with a pie-wedge cut out of it. The cut-out pie-wedge creates the exposure when it is rotated past the frame. On reflex cameras like the Panaflex, the face of the shutter is a mirror, so as the shutter is closed and not exposing a frame, the image from the lens can be bounced off the mirror to an eyepiece for the camera operator to see. As you might expect, the moment the frame is exposed the eyepiece is blacked-out (no mirror behind the lens at that moment). When looking through a reflex movie camera while shooting, the image does flicker.

Of course, shuttle movements in optical printers, downshooters and most stage moco cameras are not designed to run at real-time speeds, and are designed to be even more precise regarding film registration. They look and work much differently.

I'll be happy to answer any questions that you might have. Brings back great memories!

Marcus

 

[blip]

Re: Movie Technology for Gearheads.1: The Panaflex. Camera

The Intermittent movement

Whoosa Whatsa?
I know I’m out of my depth when I don’t understand more than three words in a paragraph, so I better go over the ^ goldmine of information (the post above) in small bite sized chunks.

So, the intermittent movement.
The fact remains that you need to stop the film for a moment while you expose it to light….or you get a confusing blur instead of an image.

Not as easy as it sounds, driving the film forward by cranking it by hand or with a spring or with an electric motor is one thing, but getting it to stop for exactly the right amount of time in a particular place at a regular intervals is a whole different level of smarts.

Yup, so how do they do it?
As usual, technology from one field spills over into another; in this case a curious set of gears invented for a sewing machine comes to the rescue of the early film makers.

Here’s a picture of it. You can see it ingeniously working in a small animation on the Wiki site here. File:Geneva mechanism 6spoke animation.gif - Wikipedia, the free encyclopedia

The really clever part is how the gear can’t slide backwards - the half moon shape locks it in place.

 

[vistaVision]

Re: Movie Technology for Gearheads.1: The Panaflex. Camera

The animation you've linked to illustrates in a very nice, simple manner how this works. If you imagine the outside pin on the green rotating disk as the "claw" that engages the filmstock perfs and imagine the red shape as the filmstock itself, you can see how film can be pulled a precise distance, stopped for a moment, and then moved again without actually starting and stopping the entire mechanism. The rest of a movie camera is simply an incredible feat of engineering and machining artistry. The movement, registration and exposure shutter are all mechanically linked with gears. One motor does all the work!

I've outlined on your original image two important parts of the camera movement. Red indicates the pins that register the perfs to ensure a steady image. When you see matte lines chattering and weaving around you are seeing the result of bad registration in the camera(s) or printers. Green indicates the pulldown claw that moves the filmstock along.

Of course, this will soon all be history...

Marcus

 

[blip]

Re: Movie Technology for Gearheads.1: The Panaflex. Camera

If you’re like me, you need to see a practical application to any theory.

Above is a Panavision camera on location during the filming of Star Wars.
The actual camera is quite small, take off the huge tripod below, remove the film cartridge on top, and unscrew the large lens on front and you have the true camera size.

Note the impromptu boxes used to seat the cameraman. Also see the spotlight sent across the side of Artoo, it’s used to give the camera what it needs most, good light.

Next : 35mm movie camera film. No, it’s not the same stuff you put in a still camera.

 

[blip]

Re: Movie Technology for Gearheads.1: The Panaflex. Camera

The Panaflex uses 35mm film.
35mm film comes as a thin strip of clear plastic, coated in several layers of light sensitive chemical, there are rows of punched holes (perforations) running along the edges.

The camera uses these perforated holes to move and then lock the film in place as each shot is taken. This process occurs 24 times every second, that’s pretty fast, so the mechanism has to be reliable. There’s also a thin strip for recording sound.

Unlike your garden variety still camera film, which runs horizontally, cinema film runs vertically.This means there are only four perforations per image, and also that image is slightly smaller.
Not sure why this convention came about, probably due to the design configuration of the early Edison arcade viewing machines.

The exactness of the perforations isn’t that important, unless you start doing special effects, that involves running the same piece of film several times through the camera. At this point you need very exact perfs.

 

[robn1]

Re: Movie Technology for Gearheads.1: The Panaflex. Camera

...Unlike your garden variety still camera film, which runs horizontally, cinema film runs vertically.This means there are only four perforations per image, and also that image is slightly smaller.
...[/QUOTE]

The VistVision format was horizontal, and shot a frame 8 perfs across. It fell out of use as a production format, but was re-purposed for effects work. ILM and Apogee used it.

[quote="blip, post: 1948268"][IMG]...The exactness of the perforations isn’t that important, unless you start doing special effects, that involves running the same piece of film several times through the camera. At this point you need very exact perfs.[/QUOTE]

The perforations were made with a punch, four at a time. They didn't match each other exactly, but they repeated the pattern every four perfs. Effects cameramen would check to see which perf best fit the camera's pull down claw, and loaded the film so that perf would be engaged. That ensured the steadiest image.

 

[blip]

Re: Movie Technology for Gearheads.1: The Panaflex. Camera

Thanks robn1. I had no idea the registration holes on the film stock were that bad. We just don’t know how lucky we are with the new digital technology.

Here’s a nice shot of the young gear head himself (George Lucas). Looks like it’s in England on the Death star set, maybe 1976. Note that the appropriate amount of the picture is taken up by the Panaflex in all it’s technological glory.
But what’s the large knob (with a white ring) at the front of the camera I hear you ask. No, not an Obi Wan saber pommel, but a lens adjusting knob.
Next : The light benders (lenses).