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Mark Golembeski

WCU-4 And Alexa Mini with EF Lenses

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Does anyone know the what control box I need in order to use EF lenses with WCU-4/Alexa Mini setup? Arri has many options such as the AMC-1, UMC, etc. I have many shoots that don't require PL lenses, BUT the EF mount doesn't have the LBUS connector built-in like the PL mount does.

 

Also, would that same control box allow me to use the WCU-4 with a different camera body - such as Red Epic, Sony, etc? I'm not finding many answers on the Internet.

 

Any help is greatly appreciated! Thanks!

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I don't think a "box" hardware solution is ever going to allow EF lens control on a Mini. The camera has limited control of EF lenses through the mount, so if it was ever to happen, it would just be in a SUP update for the MIni. If it ever comes, it would probably be a little while.

 

If you want to use the WCU-4 on another camera, you just need a UMC-4 motor controller, and you mount it on the side of the Epic or Weapon or F55 or whatever, and plug the motors into it.

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You'll have to put gears on the EF lenses and use motors.

 

 

The UMC-4 has an LBUS port to power Cforce mini motors, or regular Arri digital motors (CLM-2, 3, 4, 5) via the 3x 12pin motor ports.

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Zacuto makes 32pitch gear strips that you can wrap around Auto focus lenses.

The issue becomes the fact that there are no hard stops on the focus barrel of an auto focus lens.........if that is what you have.

You'll never know where you are on the lens since the barrel can continually rotate.

 

 

Ramon

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Hey gang, I think I found my answer. I spoke with an Arri rep and this is what they said.

 

If you're using EF lenses (in my case, Rokinon primes), you would need the AMC-1 to power the motors, since there is no LBUS connector on the Alexa Mini EF mount (like there is on the PL mount).

 

Also, for using the WCU4 on other camera bodies (such as Epic, Sony, etc), you would also need the AMC-1.

 

But, from what I've also heard, is that yes, you can use the UMC-4 as well. I think the main difference between the two controllers is that the UMC stores lens data and the AMC does not.

 

Hope that helps! Thank you all for your responses.

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That is correct. The AMC-1 is a limited, smaller controller only for Cforce motors. If you use that, there is no lens mapping, lens data, or premarked forcus rings. That's why I didn't mention it. You forgo a lot of WCU-4 features if you pair with it.

 

The default receiver for the WCU4 is the UMC4, for all those fancy WCU4 features. He only mentioned the AMC because he figured you were trying to save money, the AMC is like $2500 and the UMC4 is about 6500.

 

I was going to say, a modern, good FIZ system is a bitch with gears on an EF lens because you manually have to set the end stops on autofocus lenses (no hard end stops). And if you goof it mid-use, all the marks go off.

 

Luckily Rokinons with hard ends will work much better.

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