Jump to content


Photo

The right loop.


  • Please log in to reply
5 replies to this topic

#1 Carl Nenzen Loven

Carl Nenzen Loven
  • Basic Members
  • PipPip
  • 98 posts
  • Student
  • San Francisco

Posted 05 October 2016 - 05:50 PM

Hey everyone,

This is really messing with me and I am trying to find the solution to this.

I have shot with both Aaton LTR, and the Arriflex SR, SR2's and SR 3's.

Now when I was looking for a camera to buy, it was to be a sound sync one, and naturally people suggested the ACL. When I look at the manual it says in the best of worlds is just under 32 db. Now I have shot on the Sr2 recently and the only real noise that we hear is the daylight spool spinning. And I know that the loop really matters here so please, if anyone could show me a proper one.

Also if anyone has a video of their camera loaded and the sound, I would be happy to hear how it should sound :)

C


  • 0

#2 Carl Nenzen Loven

Carl Nenzen Loven
  • Basic Members
  • PipPip
  • 98 posts
  • Student
  • San Francisco

Posted 05 October 2016 - 06:57 PM

Just to follow up. I found this video of this nice gentleman showing the NPR he used when he worked at BBC, and mine is a lot louder than this.

https://youtu.be/gvpNwVBqzhw?t=3m8s

C


  • 0

#3 Gregg MacPherson

Gregg MacPherson
  • Basic Members
  • PipPipPipPip
  • 1674 posts
  • Other
  • New Zealand

Posted 05 October 2016 - 07:00 PM

The ACL II specs I have give 28db. The three ACL IIs that I've scratch tested were all noisier than the old ACL I that I used to use. That camera had done an enormous amout of work before I got it, but was regularly serviced by an experienced guy, and only ever ran at 24/25 fps.

The things that I think affect the noise are...(me being no camera tech, just from using and familiarity)

- Fresh film was normally quieter. I assumed that the tech used fresh film when tuning the camera, still dimensionally accurate and lubricated.
- A service tech with the right experience.
- A properly serviced camera.
- Care with loops.

With the mag off the camera should be quiet, just the whisle of the mirror and a very faint tick tick from the movement. If not it needs the doctor.

The loops can be set as they say in the manuals. Check that 13 perfs are visible when you pull the fillm out the front. There should be a slightly bigger loop at the bottom than the top. If one is careless setting the loops and mounting the mag then the loops can shift towards the top or bottom and be a bit noisier. You can actually put the perf in a precise place on the pressure pad, inch the sprocket drive, check loop sizes, and position the camera claw so it will pick up a perf almost straight away.

Sometimes when you mount a mag the mag drive shaft does not click straight in, which can mean that the loops go a little off. It's a good practice if one is new to ACL or if one has temperamental mags, to take the take up door off after mounting the mag and while running, check the loop sizes. Certainly I would do this when scratch testing and familiarising oneself with the camera and mags.

On a properly serviced camera I found all the noise came out the back, where the nose of the mag fitted to the camera. If you use a soft barney it dissapears. I used an Arri BL barney that was just flopped on top without being wrapped at the front and it worked great.

Final thought. To compare the different cameras for noise, they all need to be properly serviced, using the same fresh film, with the same environment and background noise. The type of noise that the different cameras make will not be the same. Get a sound recordist involved with your noise tests. Talk to old sound recordists who have worked near these cameras years ago.

If you do do some testing, try and compare the earlier mags with the single piece pressure plate, to the tater ones with the centre pressure plate. Also, the sound deadening is not the same on all mags. Did all or only some have sheet lead?
  • 0

#4 Carl Nenzen Loven

Carl Nenzen Loven
  • Basic Members
  • PipPip
  • 98 posts
  • Student
  • San Francisco

Posted 05 October 2016 - 08:22 PM

The ACL II specs I have give 28db. The three ACL IIs that I've scratch tested were all noisier than the old ACL I that I used to use. That camera had done an enormous amout of work before I got it, but was regularly serviced by an experienced guy, and only ever ran at 24/25 fps.

The things that I think affect the noise are...(me being no camera tech, just from using and familiarity)

- Fresh film was normally quieter. I assumed that the tech used fresh film when tuning the camera, still dimensionally accurate and lubricated.
- A service tech with the right experience.
- A properly serviced camera.
- Care with loops.

With the mag off the camera should be quiet, just the whisle of the mirror and a very faint tick tick from the movement. If not it needs the doctor.

The loops can be set as they say in the manuals. Check that 13 perfs are visible when you pull the fillm out the front. There should be a slightly bigger loop at the bottom than the top. If one is careless setting the loops and mounting the mag then the loops can shift towards the top or bottom and be a bit noisier. You can actually put the perf in a precise place on the pressure pad, inch the sprocket drive, check loop sizes, and position the camera claw so it will pick up a perf almost straight away.

Sometimes when you mount a mag the mag drive shaft does not click straight in, which can mean that the loops go a little off. It's a good practice if one is new to ACL or if one has temperamental mags, to take the take up door off after mounting the mag and while running, check the loop sizes. Certainly I would do this when scratch testing and familiarising oneself with the camera and mags.

On a properly serviced camera I found all the noise came out the back, where the nose of the mag fitted to the camera. If you use a soft barney it dissapears. I used an Arri BL barney that was just flopped on top without being wrapped at the front and it worked great.

Final thought. To compare the different cameras for noise, they all need to be properly serviced, using the same fresh film, with the same environment and background noise. The type of noise that the different cameras make will not be the same. Get a sound recordist involved with your noise tests. Talk to old sound recordists who have worked near these cameras years ago.

If you do do some testing, try and compare the earlier mags with the single piece pressure plate, to the tater ones with the centre pressure plate. Also, the sound deadening is not the same on all mags. Did all or only some have sheet lead?

Thanks for such a complete post Gregg.

I just learnt how to load the Arriflex BL-series, and the 35 III, and the loops there are essential when it comes to running silent. Now I know my ACL is in need of a CLA, but I wonder how much that can “fix” in this scenario, and what is actually just the lowest noise possible.

I considered a Barney as well, but finding a place that makes one seems a bit hard.

Also, I only use lenses on adapters, how much do you imagine that adds to it? When I did my last test it was without lens as well, maybe the weight blocks some sound as well?

C


  • 0

#5 Gregg MacPherson

Gregg MacPherson
  • Basic Members
  • PipPipPipPip
  • 1674 posts
  • Other
  • New Zealand

Posted 05 October 2016 - 09:02 PM

Please read carefully.  The noise is not just down to the design,  the service skill is important,  I always thought anyway.  If you need really quiet,  my guess is get an XTR or SR3 and have it serviced by a a guy who knows how to make them quiet.  Or just throw a barney over your ACL. Barneys come up on eBay now and again.  Getting a pro made one is too expensive maybe.  I don't believe it needs to fit ACL carefully,  just drape over the back.

 

Somewhere,  someone has an unused barney on the shelf just waiting for you.

 

It's not meaningfull to do noise tests without a lens,  though I supose it tells one something.  Should we not use the same lens for each camera?


  • 0

#6 David Cunningham

David Cunningham
  • Basic Members
  • PipPipPipPip
  • 1029 posts
  • Cinematographer

Posted 06 October 2016 - 09:58 PM

Talk with Bernie at Super16 Inc. he serviced my ACL and now you can barely hear it running unless you are holding it against your head on your shoulder. I've even had my actors ask if it's really running. It should be about as quiet a camera as you'll see, certainly for the lower cost side of things.
  • 0


CineLab

Metropolis Post

rebotnix Technologies

Gamma Ray Digital Inc

Glidecam

Ritter Battery

CineTape

Technodolly

Broadcast Solutions Inc

Paralinx LLC

Pro 8mm

ZoomCrane

Rig Wheels Passport

The Slider

Abel Cine

Willys Widgets

Visual Products

Tai Audio

Zylight

Aerial Filmworks

FJS International, LLC

Quantum Music Works

Tai Audio

Ritter Battery

Willys Widgets

Abel Cine

Aerial Filmworks

Zylight

Paralinx LLC

FJS International, LLC

Quantum Music Works

Gamma Ray Digital Inc

Pro 8mm

Visual Products

CineTape

ZoomCrane

Rig Wheels Passport

Metropolis Post

Technodolly

rebotnix Technologies

Glidecam

Broadcast Solutions Inc

The Slider

CineLab