Steadiness

[Martin Escalante]

Hi,

 

I?m working on a feature in Mexico. We are filming super 16 in 2:35 using an Aaton Xtr Prod. We did some tests recently and noticed that the registration was really bad on many shots. We had done some tests a few months ago and noticed some unsteadiness but this time its gotten worse. We did a telecine and noticed it right away. The movement is a kind of circular motion with both side to side and up and down wobbling. It is most noticeable in a shot with a zoom lens with the camera on a tripod filming a frame chart, the movement looks very bad on this shot. It is noticeable on all the shots with a tripod, and we made sure that the tripod was very stable and no one was touching the camera while we filmed many of the shots.

We are scheduled to begin shooting on Nov. 1 but there is no way we can film with this problem. I may need to take the camera to Abel Cinetech in Los Angeles, which would set the filming schedule back 1 week!

 

Is there anything I can do before I take it to a technician, to try and solve the problem?

 

 

thanks for any help... -Martin

[Mitch Gross]

First thing is to make sure it is actually in the footage and not the transfer (I assume you're looking at video dailies, but this would hold true even for film dailies). Shoot a registration test. Get some grid paper and tape it to a wall. Film a minute or so of this, rewind the film in a changing tent and then film it again slightly offset. When you get back the material in either film or video, if the two grids move relative to one another then the problem is in the camera. If the two grids move together then the problem is in the printing or transfer. Many older transfer machines such as the Rank Mark 3 could wobble terribly in 16mm, especially as tension grew near the end of a large flat. Insist on flats cut no longer than 800'.

[Nathan Milford]

Is it consistent through all of your magazines?

 

It could be a lateral tension issue, but it could be that the plate tension is out of spec.

 

Shoot a reg test and if you still have issues send it off to the guys in LA and send them the reg test also. You can get a good idea of the ailment based on the movememnt.

 

Good Luck,

- nathan

[Martin Escalante]

Yes its consistent on all the mags. we did a reg test with a black cross on white paper but it didn't do any good because we wound the film too far and there is only about 1 second of both of the cross' overlaping. I do know that the framing chart that we filmed and some other shots with a lot of movement were done with the camera on a tripod and no one touching it. The trasfer for both the tests were done on up to date machines. the older tests were processed at fotokem and transfered at post logic in LA (where we had them scaned and blown up to 35) and they also showed some of the same kind of movement. sometimes the movement is not so bad, but at other times it is huge. do you think its necesary to shoot a well done reg test before making any big decicions? -martin

[Nathan Milford]

Well if you bring it into the shop we'd shoot one of our own. But it'd be nice to get another source of information before we explore the camera beyond a basic check in.

 

First we'd do an all points check and make sure if everything is in Aaton spec. Usually if there is a registration issue, something is wildly out of spec as the prod can take a lot of punishment.

 

If nothing is amiss, we shoot a reg test and the type of motion will give us some direction as to the nature of the problem. Sometimes it's an unset claw, where the film is riding the ramp of the claw instead of the flatness.

 

- nathan

[Martin Escalante]

Well if you bring it into the shop we'd shoot one of our own.  But it'd be nice to get another source of information before we explore the camera beyond a basic check in.

 

First we'd do an all points check and make sure if everything is in Aaton spec.  Usually if  there is a registration issue, something is wildly out of spec as the prod can take a lot of punishment.

 

If nothing is amiss, we shoot a reg test and the type of motion will give us some direction as to the nature of the problem.  Sometimes it's an unset claw, where the film is riding the ramp of the claw instead of the flatness. 

 

- nathan

<{POST_SNAPBACK}>

thanks

hopefully I can do another test soon. I can also take the camera to you're LA shop to get the same service right?

 

-m

[Nathan Milford]

Absolutly! The LA crew consists of some swell and talented folk.

[dangertree]

Absolutly!  The LA crew consists of some swell and talented folk.

<{POST_SNAPBACK}>

 

Come on Nathan, we know you hate them all.

 

:-)

[Nathan Milford]

>8)

[Laurent Andrieux]

In France we do what we call fixity tests, like your reg tests, but we have a special chart for this, with a cross, etc...

 

If you weren't able to do this test, I'm sorry fellow that I would doubt of the quality of you mag and camera loading, as well as for the proper setting of the camera on the head... ;)

 

1) Make sure you properly load the magazine, especially concerning the loop length.

 

2) Make sure the camera is well tight to the plate and the plate to the head.

 

3) Do the reg test properly (underexpose 1 stop for each pass, as you pass twice)

 

Do the test for each magazine.

 

4) It might be the lateral pressors, but the problem source can also be the negative stock !

 

I once had this problem.

 

Take the processed stock and look carefully of the regularity of the perforations. Are they done according to a well constant place ? Mind the distance they are from the edge of the film. Is it strictly constant ? If you put two bits one upon each other, you can easily figure this out.

 

Is the perf always at the place referenced from the print image ?

 

If the camera and telecine are OK, I would bet the problem is the negative stock. Does anybody around you have a short end of a well improved stock so you can do a reg test with that and clear this out ?