Film-Tech Forum ARCHIVE: 12,000 fps film camera!?!

This is topic 12,000 fps film camera!?! in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=003886

Posted by Bobby Henderson (Member # 840) on 08-19-2002, 11:00 PM:

I just saw a report on CNN about a motion picture camera that can photograph up to 12,000 frames per second. The report showed footage of a water balloon (filled with milk?) dropping and exploding on this fellow's head in extreme slow motion. The footage was really cool.

The reporter said, "computer animation may be great, but this is real."

Posted by Randy Stankey (Member # 64) on 08-19-2002, 11:37 PM:

Dude! That's, like, 750 feet a second... 500 miles per hour... Mach 0.6!!

How the hell do they pull the film through the camera at those speeds without tearing or stretching the film?! Polyester, even?!
How do they keep the camera from blowing up under the stress, for crikes sake?!

Posted by Josh Jones (Member # 447) on 08-19-2002, 11:39 PM:

It is possible, although at that speed, you need an extremely fast film or LOTS of light. a 2000 foot reel will only last a second or two. They can get away with that by using a prism shutter and having the film move continuously through the camera gate.

its been done for years, the Photosonics cameras can reach several thousand frames per second.

Randy, all camera stock is acetate, mainly to protect the mechanism in the event of a film jam, the film will just shear. Somewhere around here I have video tape of a photosonics camera running through a roll of film in about 3 seconds. cool to watch

Josh

Posted by Steve Guttag (Member # 268) on 08-19-2002, 11:40 PM:

It isn't as impossible as you might think....I'd be willing to wager a rotating prism is used instead of a claw/shutter. Then, I'd be willing to wager each frame has to be hand centered to remove instability associated with the process. At least, that is how they had to be done in the good old days.

Steve

------------------
"Old projectionists never die, they just changeover!"

Posted by Josh Jones (Member # 447) on 08-19-2002, 11:42 PM:

Steve,

Thats still how its done, although I bet that cameras have gotten more stabile over the years. the prism mechanism is about the only way to do that.

Josh

Posted by Stephen Furley (Member # 1277) on 08-20-2002, 01:55 AM:

The film doesn't have to mode that fast, these cameras use 16mm film, and it moves continuously, and it runs up to that speed, so the acceleration, is within what the film can stand. I seem to remember that the film stock uses a longer perforation pitch to normal camera stocks, I'm not sure if this just means normal .03" rather than 0.2994 short pitch used in normal cameras, or something else again. John?

You need fast film, and a lot of light, but not for very long; try the 1.75 second duration PF330 flashbulbs from www.meggaflash.com . They are not cheap.

Posted by Paul Mayer (Member # 355) on 08-20-2002, 03:00 AM:

Or the film doesn't have to move at all. EG&G designed and used cameras like that for recording the atomic tests that used to be done at the Nevada Test Site, about 90 miles from here. Basically the film was loaded as a helix onto the inner surface of a cylindrical chamber. A rotating prism or mirror assembly, riding on a central corkscrew pitched to match the width of the film, was then used to expose the film. Those cameras achieved very high frame rates with almost no moving parts.

Posted by Scott Norwood (Member # 30) on 08-20-2002, 05:10 AM:

At least for 16mm, high-speed cameras use ESTAR-base film with "long-pitch" perforations, presumably in order to avoid damage to the camera movement that might result if acetate film were to break while running. Even Bolexes aren't supposed to be run without film above 32 fps.

Posted by Phil Hill (Member # 371) on 08-20-2002, 05:42 AM:

A camera running that frame rate probably is a "drum" type camera...a couple feet of film wrapped around a high-speed spinning drum. Only good for an exposure that lasts a split-second.

Rotating prism cameras top out at about 5kfps and indeed use ESTAR film as Scott mentioned. They have to hold 1000' of film since most of it is wasted while the camera accelerates up to the desired exposure speed.

>>> Phil

Posted by John Pytlak (Member # 331) on 08-20-2002, 05:52 AM:

Some links:
http://www.alangordon.com/r.hispeedpin.html
http://web.umr.edu/~boom/facilities.html

Spin Physics was a subsidiary of Kodak for many years. Their high speed video cameras (12,000 fps) are used throughout the world:
http://web.umr.edu/~boom/photo2/sp2000.jpg

Many Kodak camera films are available on ESTAR polyester base and with "long pitch" perforations for use in high speed instrumentation cameras. Most of the automobile "crash tests" are still captured on film.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Posted by Gerard S. Cohen (Member # 994) on 08-20-2002, 08:20 AM:

I've seen those ultra-hi-speed cameras offered on Ebay several times at ridiculously low prices. They're bright yellow monsters requiring
special cables and attachments, of no practical use to the average purchaser, and too huge and ugly to interest collectors.

Posted by Randy Stankey (Member # 64) on 08-20-2002, 08:41 AM:

Oh, I get the part about fast/sensitive film, bright light and rotating drum transport & shutter mechanism. I've seen TV shows where they tell you how they work. Those cameras take pictures in the 2-5,000 FPS range.

They look very cool! It takes a while to get up to speed and the last few feet of film are trashed too because the tail gets chewed up from whipping around so fast. I imagine they are the "Formula One" of movie cameras. They SOUND like it too!

I don't doubt they can get a camera to run at 10,000 + FPS... They obviously have. It's just that incredible things like this have a tendancy to warp the brain if you think about them too much!

Posted by Mark Gulbrandsen (Member # 72) on 08-20-2002, 09:28 AM:

Actually the film is fastened to a drum and spun up to speed, then an exposure is made. So simple its stupid! The present version only holds about 150 frames of film though. They are claiming it to be the highest speed camera yet developed. Randy, your 500mph speed calculation is correct according to the article I read yesterday about it.
Mark

Posted by David Stambaugh (Member # 1102) on 08-20-2002, 11:50 AM:

I caught part of that story on TV this morning. They did take after take of the water balloon falling on the guy's head before they got the shot exactly the way they wanted. I only caught a glimpse of the actual camera. Looked like the film magazine held more than 2000'.

Posted by Randy Stankey (Member # 64) on 08-20-2002, 03:23 PM:

With a drum spinning that fast, (as fast as I imagine it would), I bet they don't need to worry about the camera moving... Built-in gyro stabilizers!

Posted by Manny Knowles (Member # 1171) on 08-20-2002, 09:38 PM:

I'd like to see a pic of that camera with its magazine in place. As Randy pointed out, such a high-speed camera would consume a standard 400' or 1000' roll of film in no time.

By comparison, the house implosion at the end of "Poltergeist" was shot at 300fps.

I read somewhere that Dolby's "Rain" trailer is composed of actual slo-mo shots of water droplets colliding. I wonder what the frame rate was for that.

~Manny (better for you.)

Posted by Matthew Bailey (Member # 601) on 08-20-2002, 11:22 PM:

I'm thinking about a camera that uses 8 mm. film or wider that would film Lego houses & buildings at 1,440 frames per second being blown apart with firecrackers. Would you be able to see any Lego parts & bricks flying in perfect focus with no blurring when projected at 24 frames per second?

Posted by John Pytlak (Member # 331) on 08-21-2002, 05:40 AM:

Filming at 1440 fps and projecting the results at 24 fps would slow the action down by a factor of 60.

One of the pioneers of instrumentation photography was Harold "Doc" Edgerton of MIT, who literally invented the strobe:
http://web.mit.edu/edgerton/main.html
http://mitpress.mit.edu/bookstore/authors/edgerton.html

Posted by Randy Stankey (Member # 64) on 08-21-2002, 10:06 AM:

A camera running at 12,000 fps would consume a 2,000 foot reel of film in 4 seconds. It would take 22 minutes to play back... A time expansion factor of 333 times.

This doesn't account for "wastage" involved in "running up" the camera and the film that gets destroyed at the end when the camera "tails-out". If you figure 25% waste (a wild guess) that would leave only 3 seconds of usable film. How do they really account for this? Do they splice in a length of "trash leader" at the beginning and end of the reel? OR do they just go with the waste factor in the camera and deal with it later?

I would imagine that if somebody wanted to film, say, an explosion and then play it back in somewhat of a normal pace they would have to do some sort of skip-frame editing/printing in order to "recompress" the film speed back to some semblance of normal speed.

Either that or the film would have to be played back at a different speed, based on the time expansion factor that you wanted to portray. What projector can run that fast? I know that projectors in studios and editing facilities can play back at fractional/multiple speeds but a expansion factor of 100 times would be BRUITAL... Let alone 300!

That shit is CRAZY FAST!

No??