FASTAX 16mm Highspeed - Model WF3
Posted 23 April 2009 - 11:56 AM
in the next days i will use my old 3M Wollensack FASTAX 16mm Highspeed Cam i bought on ebay a couple of years ago. Haven't used it EVER til now. Now i hope that i do everything right, and maybe some of you have worked with this before.
I am shooting the squashing of a balloon for a documentary to explain what can happen in a plane crash.
The camera is the 4 prism WF3 model that uses 16mm double perf film.
I don't have the goose unit and so i built something to ramp it up to the final speed.
We will shoot outside at noon and have some 5 Kilowatts Tungsten Lamps to "support the sunlight".
Will that be enough? And is there anything else with these models i must know when shooting.
I thank you in advance for every tip that may help here...
Posted 26 April 2009 - 01:20 PM
Edited by Jason Hinkle, 26 April 2009 - 01:24 PM.
Posted 26 April 2009 - 01:51 PM
Presumably you know that the WF3 doesn't have a regulated speed. You have to be running at the correct speed when you trigger the event. That's why we always used a sequence timer to start the camera, allowing it time to run up to speed before triggering the event.
The only way to calibrate the running speed is to run test films at a range of voltages and then plot speed against time- in addition to a power supply you also need to drive the timing lights which will place a mark on the edge of the film at a known frequency. If you don't run these tests you will be quite unable to achieve a predictable running speed at the time you trigger the event.
Assuming all this is in order, you can work out the exposure time for your desired framing rate with the 4-sided prism from the shutter factor engraved on the prism. This will be either a ratio, such as 3, or an equivalent shutter angle, such as 120 degrees. If a ratio, multiply by your framing rate to get the reciprocal of the effective shutter speed; if an angle, divide into 360 to get the ratio. I don't recall the ratio for the WF3- I never used it in the framing mode- but it will be a number like 3 or 4.
You can then work out if you have enough light with a meter but I have to say if you're expecting to run at anything over 1000fps, bright sunlight will barely be sufficient. We occasionally got away with it, but only with 400ISO stock. If you work it out at 1/3000 of 1/4000 sec that's about f/4.
Posted 26 April 2009 - 06:49 PM
Although i can't control to run it at an exact speed i'll try to find out how to run it at 800 - 1000 fps. I'll do this just by using a test roll of one daylight spool and run it at different voltages. This will let the daylight spool be pulled through in 4-5 seconds. By that i'll have a theoretical exposure time of 1/5000 in the occuring event. I will have 500T double perf Vision2 that i hope is still okay after 4 years in the fridge. Hopefully i'm allowed to post the results. If there's more for me to know please hit me...
Posted 27 April 2009 - 12:44 PM
You still have the problem of not knowing when the speed is correct; as I said, the WF3 is unregulated and will just keep on accelerating until it runs out of film. The best you can do is assume the speed-time curve is a straight line, which it will be, more or less, at the low voltage you need- and work out your notional 1000fps from that. I suggest testing voltages around 30-50V, although that is a complete guess. I've never run a WF3 that slow.
As to plotting the speed/time curve, and approximating it to a straight line, you know that the roll is 30m long. Say it runs through in 5 sec. Plotting speed against time, the area under the line is your 30m, so the maximum speed is half the base times the height, or 12m/sec. You can then measure off the time at which the speed will be your required 1000fps, or just under 8m/sec. I don't have my graph paper handy so you'll have to do that yourself.
Try voltages around 30-50V, although that's a complete guess. I never ran a WF3 that slow. It doesn't run well at low voltages; you really are in the dark working without timing marks.
There's no reflex focusing, so you have to focus through a loop of film in the gate; we used a special focusing film with a surface like ground glass. Chips of film may need to be removed with tweezers; at high speeds we used a vacuum cleaner.
Posted 27 April 2009 - 03:44 PM
My calulations were done with a stopped down lens (f4). Sorry that i forgot to write that. I will calulate, do one test and then shoot again with a fully open iris. I have parts of the manual and the curves are in there, so i'll try to measure the ingoing voltage now and hit the 50V you suggest. Thanx Mark, you are very helpful here.
Posted 28 April 2009 - 03:39 AM
Posted 29 April 2009 - 06:02 AM
If you will need upgrade of control of speed of camera, can ask me.
I have experience and controllers for upgrade of cine cameras on crystal sync speed control.
Posted 29 April 2009 - 10:26 AM
Yes, it exists...
even has an e-mail address on the photocopy. Not too bad for a 1966 camera...
Posted 05 May 2009 - 02:08 PM
Visual Instruentation must have taken on the support in the 90s- when we bought replacement Fastax 1s in 1990 at about £6500 each they were being made by Redlake, but the old grey WF3s from 1963 were mostly still going strong. Apparently the original was designed by Kodak on the 30s for Bell to study relay bounce. Bell took over the development themselves, then it passed via 3M to Wollensak.
Posted 08 May 2009 - 11:10 AM
Posted 08 May 2009 - 11:41 AM
We just shot our highspeed footage as planned. It took a while now, but it was very sunny today and we had additionally lit with 2 silver reflectors. The 500T 2 perf didn't jam and i think it was 2000 fps at the peak of the curve when we "pulled the trigger". The photos are from our wonderful PA Iris Kreidel.
Posted 08 May 2009 - 12:26 PM
We just shot our highspeed footage as planned.
That looks interesting. What are the little yellow objects, and where were they before the ballon was punctured? They seem to be moving at very different speeds, and the lens doesn't look long enough to account for that. Please do post some frames from your high speed shoot.