Home of Professional Cinematography since 1996
Time Lapse Flicker
>I recently did some manual time lapse with an Aaton XTR S16; averaging 1-2 second exposure times and 2-3 sec. intervals. Seeing that I wasn't using an intervalometer I didn't expect it to be perfect, but there was a white flicker effect in most of the material. In the past, I have done the same thing with a Bolex, and the shots were perfect. Can someone explain this to me?
>Alain Julfayan / LA
>Was the white flicker a sort of line across the frame, in about the same place on the frame? It sounds a lot like a mag leak, meaning a leak at the point where the mag fits onto the camera body. I'm not familiar with Aatons at all, so forgive my ignorance of how the mag fits to the camera.
>Next time, always assume that there is no such thing as a light tight camera, tape the door and seam where the mag joins the camera, and cover it with something so not to allow direct light to hit the camera or mag anywhere.
>I have a test procedure for checking cameras out for light-tightness and animation worthiness. When I find it, I'll post it on the list.
Gear+Rose Motion Control
>I've just shot a lot of time-lapse with an Aaton XTR and it was fine.
>The time lapse controller was from CE, correct me if I'm wrong Justin, and although it had variable frame rates it was a fixed exposure of 1/4 of a second.
>I think the problem in the case we're discussing here was due to the single frame advance on the camera being used manually to shoot a frame at a time, I wouldn't really expect that this would give a constant exposure.
>Oh good it looked nice...They didn't pay you by any chance did they ?
>Well putting on my anorak for one second. :) By my understanding (which is pretty slim I grant you, But you can fool some of the people some of the time) I thought an intervalometer was just a device (like the CE) that simply gives a pulse every x secs or mins. And that a time lapse controller was a device like the norris TLC.
>An intervalometer simply tells the camera when to shoot a frame (now here is where my knowledge gets really dodgy) I guess on the Aaton or SR (with board) it just triggers the "Test" circuit. A CE intervalometer will run any camera that has such a facility. (as it happens I am buying two at the moment for my bolex co). The only way to change the shutter speed from 1/4 sec on the Aaton is to vary the shutter.
>A time lapse controller is like the norris which is a separate stepper motor that bolts onto the camera and then has a controller where you can set the shutter speed and interval.
>However the donkeys gonads as far as this sort of thing is concerned is the Arri ICS and hand controller thingy. Basically with a 435 ES you can make exposures from 1sec duration to 1/125 with a practically unlimited interval between them.
>Two weeks ago actually! I'll talk to the producer today
>I knew that you would... OK Intervalometer and not Time-lapse controller, but don't some cameras have to be modded to use these and what are the mod's? ie it's not just a straight firing of the frame advance??
>Sorry, I haven't used a Bolex to shoot timelapse since college, and that was.... well I don't want to date myself. The cameras in college had the same type of solenoid arrangement you speak of.
>The last time I shot single frame with a bolex was for an off the wall network promo, where I was walking around the NY Fulton Fish market at 3AM shooting roughly continous single frames about 1 every second or two. Wild looking stuff. Hand held timelapse.
>Regarding time lapse with an Arri III , with capping shutter and a Norris : Watch out for direct light sources bouncing around the interiors behind the lens , with regards to the mirror.Small shutter opening and black "paint" on the edges off the mirror reduces problems.
>On Aaton , I sometimes go veerry slow , and later I omit the frames not needed. A stock consuming method but comes in handy on location without any ICS Timelapse Intervalometer Norris Single Frame controller Set Up by CE.
>A nice setup is also to hook up ARRI´s excellent ICS system with the Kuper Motion Control software to do a "real" Intervalometer shot with time lapse, between exposures , changing regarding to subject (such as baking bread etc)
>Those old Mitchells, they have seen a lot of refurbishing over the years. Oh yes , but >my two very trusty and very refurbished Mitchells, have never leaked. (Light , that is )
>Now we are on the Mitchell subject: Anyone having experience with digital videoassists ?
>Allan "laps" O , AC.
>Well putting on my anorak for one second.
>Yes some cameras must have an internal mod. But this is where my geekness starts to fail. I KNOW that the Arri SRII needs either a mod or this only works on later cameras. The guy who really knows the answer is John Duclos for Arri or Alan Giles for Aaton.
>Justin "How on earth did I get involved in Timelapse" Pentecost
>Don Canfield wrote :
>Anyway, the question I have is about the setting of the "speed dial" on the Bolex >during time-lapse work...I was told years ago to always set this dial to 64 fps to allow >maximum torque on the spring.
>Allegedly (as in according to the Bolex RX5 Manual).
>"You can also use an electric motor which ensure absolutely constant exposure time for every frame at the selected speed. This prevents the slight flicker which inevitably results from useing a spring motor"
>Bolex Spring single exposures do flicker but setting the speed dial will not change it much. On a really old or abused camera a new spring will be much better.
>On the Millenium Dome project we are useing RX5's with Tobin TTL motors which I must say seem very good (and simple to use given my brainpower).
>A nice setup is also to hook up ARRI´s excellent ICS system with the Kuper Motion >Control software to do a "real" Intervalometer shot with time lapse, between >exposures , changing regarding to subject (such as baking bread etc)
>Can you elaborate on this? I've been wishing for a way to control an Arri via Kuper for years. I thought with all the computerization of the 535's and 435's this would be a no-brainer. For some reason, it has not come to pass. How do you use the ICS with Kuper? Can it receive an external pulse/switch closure to make it shoot? Is there more? I haven't been able to fully check it out yet, but the AC I'm working with this week told me there is a DB9 pin connector on the unit.
>Just beside myself with questions,
>Don Canfield Gear+Rose Motion Control
> I KNOW that the Arri SRII needs either a mod or this only works on later cameras.
>With the Arri SRII, the Norris timelapse motor works quite well, with any modification. I own one and have a Norris intervalometer and capping shutter for it as well. I've had some power supply problems, but other than that, it works great.
Try giving Abel Cine Tech a call. If they can't answer your Aaton questions, you might be out of luck. I spoke with Ian at Abel LA about time lapse recently, and he said that they recommend covering the lens if the time between exposures is more than 20 seconds, so that could be part of your problem. They've just started building a new intevolometer for Aatons, BTW, called the E-Shot which only does 1/4 second exposures on older cameras, but can do timed exposures on newer ones.
>Their web site can tell you all about the E-Shot ... it's www.abelcine.com
>Sorry, If the impression was that I had done it - I have not ! My first ARRI / Kuper Joint was a IIC with the standard motor replaced with a stepper. Actually they shot for 14 months on this camera, butterfly mirror and all.
>The next one was a ARRI III, with the motorshaft prolonged, and supported by a ballbearing, out on the right side to a gearwheel, with a belt going back to a stepper,mounted on the handgrip dovetail on the back. Many problems with the mirror and the missing Internal Capping Shutter , but the mechanics worked all right.Then the Mitchells where tried and Mr Swenson: I am sure you are right about light leeks and I also have wondered on the chunky lighteating videotabdesign from the stubborFriesned engineers off hollywood.Never the less I could have been lucky ? Anyway, we use a lot off tape , especially over the video/mirror slider.
>With the ARRI ICS system , wich I do not have in my posseion as of yet , there seem to be a new computerized chapter regarding timelapse/ intervalometer cinematography (e.g. large variety in exposuretime qua motorized shutterangle connected to a lightmeter via controlbox) Since it is possible to acces the Singleframe RS232 Protokol(via the DB 9), with commands like: SF-Mode on/off ; Set SF - exposuretime ;ICS open/close etc.,one could wish for a piece off software to run on a labtop for controlling all camera parameters in timespace. Maybe it is possible to refine the Kuper software to talk ARRI RS232 language also ? (Are you listening in here Mr. Thomas?)
>I am sure it can be triggered , hence the green button on the box .
>Allan "trig" O
>Allan O Luckow wrote :
>Maybe it is possible to refine the Kuper software to talk ARRI RS232 language also?
>No, It's, "Are you listening Mr. Shipman Mueller?"
>Marc at Arri is quite aware of our FX/MoCo needs from the 435...
>Eric Swenson VFX Dp
>A limelapse flicker problem I have encountered involved an Arri 2c (which has an adjustable, mirrored, "butterfly" shutter. The mirrored shutter is rotating at 1/2 the speed i.e. 12 frames per second because it is designed with TWO openings, providing exposures per revolution. Is this clear? If one does not use the capping shutter, offered by Norris Intervalometers, light can leak around this butterfly, mirror shutter and expose the film in mid-frame pulldown, causing a aperture plate frameline image to be deposited wherever the camera movement is phased to stop BETWEEN exposures.
>Another flicker problem can happen withh the 2c (or ANY butterly reflex mirror/shutter) when (with adjustable shutter!) the shutter is stopped down to a tight (i.e., 15 degree or less openning). One side of the shutter is actually making a significantly different exposure than its opposite side due to inconsistensies in the two openings.