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Iris control unit (ICU)


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#1 Allyn Laing

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Posted 07 October 2008 - 11:38 PM

Hi Guru's,

I am trying to achieve the following shot.


Keeping the same frame rate, increase depth of feild and keep a constant exposure.
The only way I forsee this is with a 435 with an electronic shutter, ICU-1 and an RCU to change the shutter during a take? I have set up that configuration, but cannot find any literature on how to get the ICU to work with the RCU(shutter change), only with a change in frame rate does the ICU-1 respond.

I have heard the ARRI WRC-1 can do this? I don't have access to one. Does anyone have a combo for the buttons or more info?????

thankyou

Allyn
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#2 Brad Grimmett

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Posted 09 October 2008 - 02:39 PM

Hi Allyn. I would speak to the rental house about this. If that fails, try Arri.
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#3 Alex Worster

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Posted 09 October 2008 - 05:58 PM

Allyn, unfortunately Arri's WRC-1 is the tool specifically designed to do this type of adjustment. Cool idea by the way. With the WRC it's a fairly straight forward procedure provided you're familiar with the unit, I guess that's what days off are for. You can find the manual on Arri's website and it'll tell you how to do it. So, the smoothest and most repeatable way to get this done is find a WRC. If you can't get your hands on one a dirty way to do it is with an RCU and a Preston FIZ or Focus/Iris unit. It helps to have two pairs of hands to do it this way. You set the the RCU to shutter adjust then define your end stops. Set the Preston to iris adjust and define your end stops or label you're T-stops on the wheel/slider. Next, do the math to make sure you're shutter/iris ramps will properly compensate its self. Now here comes the fun part, both people will try to manually ramp their respective units at around the same time and with the same duration to destination. With some practice the slight variations in exposure shouldn't be too bad because the ramp will probably be fairly quick and the end will look fine if you did your math right. Like I said, it's not ideal but it should work if you can't get your hands on a WRC. The WRC would make things a whole lot easier. Hope that helps.

Edited by Alex Worster, 09 October 2008 - 06:01 PM.

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#4 Rolfe Klement

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Posted 10 October 2008 - 05:55 PM

there was a demo video of this somewhere on the web that I saw - it was a great effect

Anyone have a link?

thanks

Rolfe
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#5 Allyn Laing

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Posted 12 October 2008 - 04:33 PM

Allyn, unfortunately Arri's WRC-1 is the tool specifically designed to do this type of adjustment.


thanks Alex, i thought this was the case. But in your reply maybe a manual look is just what I'm after???? if only they made a 16mm with an electronic shutter.

thankyou everyone for your reply

Allyn.
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#6 Satsuki Murashige

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Posted 13 October 2008 - 01:28 AM

If a rough looking "manual" effect is ok, then what about using an ND grad filter in the matte box and sliding it gradually from dark to clear while compensating with the iris? Or you could possibly use that Rosco polarized variable ND gel by stretching it tight on a frame and mounting it in front of the lens like a teleprompter. Then use a pola in the matte box to slowly dial out the ND and compensate with the iris.
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