I have a commercial shoot coming up which calls for single frame shot (time lapse of a sunrise).
We will be using an Arri III for the shoot. Does anybody recall the factory-set shutter speed on single frame?
If you are using a Norris intervalometer the fastest exposure time is 1/16 sec.
You will need an intervalometer because the Arri III only goes down to 3fps although you might be able to get an inconsistent 2fps out of it. Order an Arri III MarkIII and you'll be able to adjust the minimum shutterspeed of your intervalometer (usually 1/16) by changing your shutter angle down to up to 45 degrees. Hope that helps
Florian Stadler Cinematographer, L.A.
If you are "forced" to shoot a time lapse sunrise time with an Arri III I would highly recommend a test using the planned exposure time, interval and the exact lens to be used. I receive many panicked calls from producers and DP's looking for time lapse footage due to light having leaked around the shutter on an Arri III.
A Norris capping shutter may reduce or eliminate this problem but is no guarantee. Some Arri III's are light tight and perform perfectly and many others are not and ruin time lapse shots everyday. To shoot the sun with absolute certainty of success use a camera with a focal-plane / blanking shutter such as a Mitchell, Bell & Howell 2709 or Panaflex.
Marc Dobiecki Local 600 - Atlanta
I second that. That's why God in her wisdom invented Mitchells with focal plane shutters.
Some rental houses use a silicone sealant on the Arri 3 gate as a light gasket when using a Norris intervalometer. Once sealed you cannot remove the gate with out losing the seal. Your best bet is to shoot at a 45 degree shutter to avoid a light leak.
By far the best time lapse rig I have ever used is from Level Seven in Toronto. The "black box" brain is attached to a Mitchell NC. On the rear of the NC there is a dial that shows the focal plane shutter position. One half of the circle is white and the other black. The gate is a white rectangle. You can instantly see the shutter position in relation to the frame at any time. The system all allows you to program ramping intervals to stretch or condense time within a program. For example, if you want to stretch out sunrise, but still want the predawn glow to go by fairly quickly, the interval ramp function can ramp to a shorter interval to capture more frames. What's really neat is the light metering system keeps the exposure even across the ramp.
Without a capping shutter you're on thin ice here. If they'll pay the freight, see if you can get the intervelometer/capping door installed on a 435. I just came off three weeks with this rig and it's incredible. With the aid of the variable shutter, gives you an exposure of 1/125 sec through several hours! Best of all, no leaks and an open viewfinder! Very easy to use, once you've been checked out... I didn't even have an AC most of the time. Put it on a little still tripod.
The cheap version is an Arri III at three or four fps, then transferred at 60fps or whatever. Depending on the body you might get consistant results setting your PSC speed control at 2.5 fps but I heard it's hard on the camera. At this continuous cranking, shutter leak won't be a problem as you'll be shooting through NDs for a quarter of a second (or whatever) exposure. But cap that eyepiece!
I'd get an ND 1.2 (four stops) in gel if possible (glass often adds an offset ghost image, if sun is not exactly frame center) and roll at 3fps if no time for a test. If pulling stops to follow the exposure, try to make each tweak a sixth of a stop or less, and don't touch the iris again until 10 or 20 frames have gone by. You might need a long stick attached to the f-stop ring to make these tiny pulls. 5245 is the stock most resistant to overexposure, if you guess wrong.
I think the sun crosses its own diameter every 50 seconds, and with winter on the way it rises at a pretty steep angle heading south, or frame right (in Northern hemisphere.) With this you can plan the duration of long lens shots. Funny, I just saw "Lawrence of Arabia" again this week...
Skip Roessel NYC DP
© copyright CML, all rights reserved