ARRI

[RonBaldwin]

the backdrive motor thing (which is new to me) is awesome. Being trapped out of focus or on the wrong thing with no way to communicate with the ac is torture!

[Mariano Costa]

Hey Eric,

 

I have a little question regarding the cage - is it universal or are there components which limit the range of cameras you can put in? I am asking because I pre-ordered a Sony Alpha 99 DSLR and this cam obviously is not (yet) listed on the Arri kits page.

 

Thanks!

 

 

Not sure of the sonys dimensions but the majority if the system is universal. What you will need is a camera specific "baseplate/riser" that mounts the camera to the cage system

 

 

aha, thanks for the info! then I hope they`ll produce one for the Sony or at least some kind of variable riser

[Thomas English]

On my hedens I was always aware you could drive the motor backwards but never knew it was healthy! Do u not loose your marks? Are you just twisting the lens till it focus's then AC is coming along and turning your handset on. Are you only doing it with the MDR is turned on so it knows what you did.. so many questions! I must try it.

[Jess Haas SOC]

With a bartech I have been told that it is safe to turn the motor when the receiver is turned off. It doesn't lose calibration, when you turn the unit back on it goes back to the mark set on the handunit.

[Mariano Costa]

On my hedens I was always aware you could drive the motor backwards but never knew it was healthy! Do u not loose your marks? Are you just twisting the lens till it focus's then AC is coming along and turning your handset on. Are you only doing it with the MDR is turned on so it knows what you did.. so many questions! I must try it.

 

Eric or someone else may have some insight into this, but in my theory, as the Arri LCS has a bidirectional link the position change should registered by the potentiometer (or whatever is sensing the rotation) in the motor and be reported back to the hand unit. With LDS or S/i lenses it should be even a lesser issue as the lens settings are generated by the lens itself. But please correct me if I`m totally wrong, it`s just speaking my theories out loud.

[Thomas English]

I just don't understand how the machine can think with its electricity off.. There must be rules.

[Jess Haas SOC]

I just don't understand how the machine can think with its electricity off.. There must be rules.

Good point. The original bartech uses analogue motors which use a potentiometer to read current position. So when you turn power back on it can read the current position no problem. As far as I know this wouldn't work with the new digital receiver as an optical encoder(which I believe is what digital motors use, correct me if I am wrong) would require power to keep track of position.

 

~Jess

[Eric Fletcher S.O.C.]

I just don't understand how the machine can think with its electricity off.. There must be rules.

Good point. The original bartech uses analogue motors which use a potentiometer to read current position. So when you turn power back on it can read the current position no problem. As far as I know this wouldn't work with the new digital receiver as an optical encoder(which I believe is what digital motors use, correct me if I am wrong) would require power to keep track of position.

 

~Jess

 

 

Two ways to do it. If power is on to the MDR the MDR just reads the new count and updates the handset when the handset is present. If no power on the MDR then upon power up it resweeps the lens and remembers the original count ((clockwise count + counterclockwise count))-clockwise count=new position) and then updates the handset with the new position

[Thomas English]

If power is off does one have to remember to press the red button?

 

I had an Arri MK3 radio FF job the other day and for weird reasons I won't go into I didn't want / couldn't to have the MDR / brain on the camera. There was no D-Tap or 4pin xlr cable in the box so I rung arri in a panic and they said

 

The mk3 can ONLY be powered off the Arri RS connector. I had to get a 9ft arri rs extension sent down!

 

I infer from this that the mk3 MDR is 24v only. I don't want to run my sled in 24v all the time. Its ok for you Eric and your XCS wizzbam kaPPOW machine but I'm not sure I want to do that and I'm not sure I want an up converter 24v box either!

 

Anyone shed any light on this?

[Rob Hess]

The ARRI follow focus units seem to be pretty nice (haven't used one myself), but I notice they aren't typically mentioned in the same league as the Bartech or Preston units. Have the ARRI units not been around as long, or is there another reason for this?

[Emmanuel Lariviere]

Hey guys, what's the status on the WCU-4? Has anyone here used it yet?

[Eric Fletcher S.O.C.]

Yes we tested it on this season of Dexter. AWESOME piece of gear. Very well thought out and implemented. Built with the typical Arri robustness we have come to rely on. So good in fact that I'm buying one and may dispose of my Preston (waiting for the outboard reciever first though.

[Emmanuel Lariviere]

Thanks for the quick response, Eric. It's good to hear that ARRI nailed it.

[Frederic Chamberland]

I have had an WCU-4 also for about 3 months now. As Eric said, beautiful piece of gear, well taught out. greatest pro is not having a MDR if you use any ALEXA + and beyond . The UMC-3A also works great and has a much smaller footprint than the MDR2 from preston.

Couple of observations when compared to PRESTON :

 

CONS

•Motor cable has to be screwed in the motor connector, big fingers will hate that. And good luck in the cold, you will have to remove your gloves to tighten the connector. I learned to leave them on the motor now, I never remove the cables anymore.

•Linking of the hand unit to UMC-3A or ALEXA varies from 3 seconds to almost 7/8 on occasions... While PRESTON is less than a second....Not frustrating since it's just a couple of seconds but you realized you never had to think about it with the Preston.

•some ARRI genuine cables for that remote are outrageously expensive ; 900$ for the EPIC on-off ? David Hable made one for 1/4 of the price.

 

 

PROS:

•No MDR (if used with ALEXA + and up)

•big LCD screen with beautiful info. Arri signature is all over the place (efficient and clear)

•light and compact Hand unit

•motors are very quiet and have a small footprint.

•backlit ring is great

•build quality

 

 

The only thing I don't have a backup in my kit is the Preston because I know it does not fail. 23 years in the business and I probably have seen one or two Preston's going down. I won't sell my Preston. But I'm keeping the ARRI.

 

Fly safe.

[Emmanuel Lariviere]

Thanks, Frederic.