Jump to content


Photo

SR2 not reaching 75fps


  • Please log in to reply
8 replies to this topic

#1 Travis Trewin

Travis Trewin

    New

  • Basic Members
  • Pip
  • 3 posts
  • Cinematographer

Posted 03 June 2008 - 07:21 PM

Hi.

I have just purchased an SR2 kit and ran some film through it to test for magazine scratching, steadiness of image, lens sharpness etc. With the onboard batteries the camera will not get beyond about 55fps. All the manuals say it should reach 75fps. The camera has a Cinematography Electronics Speed Control unit fitted. Can anyone shed some light on what might be wrong? The batteries are my guess - were recelled in June 2006.

On another topic, the camera has an NTSC video tap fitted and I need a PAL signal to view and record. Any ideas on a simple (and portable) way to alter the signal?
  • 0

#2 timHealy

timHealy
  • Basic Members
  • PipPipPipPip
  • 1252 posts
  • Other
  • New York

Posted 03 June 2008 - 09:13 PM

Can you read the voltage on your batteries after they are fully charged? And you may to try and read the voltage when operation. Perhaps try with a different battery or and AC adapter.

Also do you when the camera was last serviced?

Then call Cinematography Electronics to see if they have any advice.

Best

Tim
  • 0

#3 Travis Trewin

Travis Trewin

    New

  • Basic Members
  • Pip
  • 3 posts
  • Cinematographer

Posted 05 June 2008 - 01:30 AM

Reading the voltage of the clip-on 'on board' batteries is difficult. I can't see any easy way of doing it because of their weird connection. I'm going to try and get hold of a different battery to try and rule the battery out as a reason. I believe it is some time since the camera had a service, but was sold to me in full working order.
  • 0

#4 Phil Savoie

Phil Savoie
  • Sustaining Members
  • 94 posts
  • Cinematographer
  • Montana / Wales

Posted 05 June 2008 - 07:51 AM

Reading the voltage of the clip-on 'on board' batteries is difficult. I can't see any easy way of doing it because of their weird connection.


You can unscrew the thumb screw that holds the Arri Battery adapter to the SR body and remove it from the body. the body side of the adapter will show an XLR female once off and it's easy to check voltage with a volt meter by placing the probes in the two outer holes (#1&4 is Arri if I remember correctly).

If its not the battery I'd check the speed control a standard speed Arri SR should indeed reach 75fps. The fact that it has a CE speed control installed makes me wonder if the CE control has been set to limit the camera speed. Larry at CE can do this - he has set up my 35mm camera with a 50fps limit for instance. Owner/Ops and rental houses will sometimes do this to limit wear & tear.

I would think that if you call up CE as Tim suggests with your SN they can check out if it was set up with a limit.
  • 0

#5 timHealy

timHealy
  • Basic Members
  • PipPipPipPip
  • 1252 posts
  • Other
  • New York

Posted 05 June 2008 - 08:26 AM

For what it is worth Abel Cine Tech use to sell a 12 volt discharger. It's main purpose was to help keep batteries healthy by fully discharging them before recharging. But you could also read your voltage under the load that the device provides. Maybe they still sell them.

Best

Tim
  • 0

#6 Travis Trewin

Travis Trewin

    New

  • Basic Members
  • Pip
  • 3 posts
  • Cinematographer

Posted 05 June 2008 - 08:03 PM

OK. I put a multimeter on the batteries and they were all reading around 12.6volts. I removed the battery adaptor and connected a large floor battery (charged up to 13.5volts) to the camera. The camera sometimes manages to reach 75fps, but only just, and the rest of the time it fluctuates between 50 and 60fps. It's almost like there isn't constant power reaching the motor. Wiggling the power cable near the connector doesn't make a difference, so it's probably not due to a bad connection. I've sent CE an email with the serial number to see if they have any suggestions. I have a battery discharger which I always use to keep the batteries in good condition.
  • 0

#7 timHealy

timHealy
  • Basic Members
  • PipPipPipPip
  • 1252 posts
  • Other
  • New York

Posted 06 June 2008 - 10:59 AM

Did you get 12.6 with or without a load on them? If no load I would think they are a bit on the weak side but should work for a short time. But since you used one really good one at 13.5, I would say you probably will have to send the body it to Arri in Blauvelt or CE in LA to really get to the problem and get it corrected. But in thinking about it I would say whatever device governs camera speed (The CE speed control) is not working properly.

But please post your results once you come to a solution.

Best

Tim
  • 0

#8 Michael Nash

Michael Nash
  • Sustaining Members
  • 3330 posts
  • Cinematographer
  • Pasadena, CA

Posted 08 June 2008 - 11:09 PM

Many cameras require switching to a higher voltage (24V) to achieve frame rates above 50 fps. Ensure that your system can handle 24V first, but I suspect a 24V battery will get you to 75 fps with no problem.
  • 0

#9 timHealy

timHealy
  • Basic Members
  • PipPipPipPip
  • 1252 posts
  • Other
  • New York

Posted 09 June 2008 - 02:12 PM

Hey Michael,

He is having camera troubles with an Arri SR 2. A 12 volt camera out of the factory. Arri started using 24 volt batteries with the SR3.

There would be no means to use 24 volt batteries on his camera. (unless there was an PS Technik 24 volt upgrade which I'm sure he would have mentioned by now ... I would think)

I have an Arri High Speed SR 1 which does up to 150 fps on 12 volts.

Best

Tim
  • 0


Media Blackout - Custom Cables and AKS

CineTape

Gamma Ray Digital Inc

The Slider

Rig Wheels Passport

Wooden Camera

Paralinx LLC

Aerial Filmworks

Visual Products

Tai Audio

Technodolly

Abel Cine

Ritter Battery

Metropolis Post

Glidecam

Willys Widgets

Broadcast Solutions Inc

FJS International, LLC

rebotnix Technologies

CineLab

Opal

rebotnix Technologies

CineTape

Technodolly

The Slider

Rig Wheels Passport

FJS International, LLC

Opal

Gamma Ray Digital Inc

Wooden Camera

CineLab

Paralinx LLC

Broadcast Solutions Inc

Abel Cine

Metropolis Post

Tai Audio

Glidecam

Media Blackout - Custom Cables and AKS

Ritter Battery

Visual Products

Willys Widgets

Aerial Filmworks