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Working with Hawk C-Series Lens


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#1 Joel San Juan SOC

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Posted 16 April 2014 - 01:31 PM

Hi,

 

Wondering if you had the chance to work with the Hawk C-series anamorphics and dealing with the barrel rotation.

More precisely is there anyway to get a clip on mattebox on since the barrel rotates along with the focus.

Are my only choices to go with the rod-mattebox combo and arri baseplate for the Alexa? Really want to use my Alexa plate for this set up without the extra weightage.

 

What do you think?

 

Best

J.


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#2 James Davis

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Posted 16 April 2014 - 05:34 PM

I think try and get yourself some carbon fibre 15mm rails and see if you can run a little rail mounted matte box that way, I did something similar with Lomo anamorphics a while ago which have the same issue of a rotating lens barrel, this meant I didn't have to use the horrible bridge plate + 19mm rails set-up and I could stick with my normal alexa plate set-up.


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#3 James Davis

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Posted 16 April 2014 - 05:38 PM

We had this matte box from Vocas which goes onto 15mm rails which run straight into the body on the Alexa: http://www.vocas.com/products/mb-435

 

It was as light as most clip-on's and kept the set-up very manageable, maybe worth looking into rental houses and seeing if they have something similar that will mount onto 15mm rails?


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#4 Joel San Juan SOC

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Posted 16 April 2014 - 08:02 PM

great James, thanks for the info!

 

Best

J.


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#5 Nils Valkenborgh

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Posted 19 April 2014 - 03:42 AM

Hi Joel,

There are couple of things to keep in to account when working with c-hawks on steadicam. The main problem is the huge amount of barrel displacement when focussing (up to 3cm fore/aft on the 35mm if I'm not mistaken). This has a couple of consequences,

1. The shift in weight fore/aft, i'd suggest balancing your sled when focussed on infinity. That way, if there's a change in focus your sled will tend to lean forward, which is the easiest force to counter.

2. Use a mattebox on 15mm rails if at all possible(I had to use the 19mm option so I don't know if it's logistically possible). a clip on will worsen the effect of point #1. You'll have to use a snoot or an extended donut to prevent light getting in between the lens and mattebox.

3. Final point and the most annoying. Not just the front of the barrel has a lot of displacement, the focusring does as well. Try to get an extra wide focus gear for your motor to get complete coverage on the barrel. Otherwise your stuck "selecting" a limited range in between the front and back reach of your focus motor.

These were my experiences with the lovely c-hawks, hopefully you can find a way around the problems they may present you.

Good Luck

Nils "long live v-lites" Valkenborgh
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#6 Joel San Juan SOC

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Posted 29 November 2014 - 12:53 PM

Thanks for your help guys. Just forgot to post the follow up. So we ended up with the 19mm rods and 6x6 Mattebox.

Was really a pain dealing with the barrel tromboning (displacement) especially since we were using the 75mm and 100mm alot. Every focus pull affected the balance so at the end, the easiest way was to keep a faster drop time to give me a little chance to react to the shifting.

 

Appreciate all your suggestions. Thanks

Attached File  Betz_C.jpg   115.84KB   10 downloads


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#7 arielmanuelsalati

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Posted 06 December 2014 - 09:56 PM

'Final point and the most annoying. Not just the front of the barrel has a lot of displacement, the focusring does as well. Try to get an extra wide focus gear for your motor to get complete coverage on the barrel. Otherwise your stuck "selecting" a limited range in between the front and back reach of your focus motor'. it's possible to find the extra focus gear for the heden digital? www.arielsalati.com
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#8 Nils Valkenborgh

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Posted 09 December 2014 - 01:09 PM

Ariel, as far as I can make out from the picture, Joel used a CLM-4, there are wide gears available for this motor, or any other Arri motor for that matter. When it comes to other brands, I know Peter Hoare now makes wide gears for his HPM-1 motors.

 

http://www.hocusprod...ide-0-8mod.html

 

They might match the Heden alignment but don't take my word for it, send Peter an email.

 

Greetings

 

Nils

 

PS: Joel, kudos to the solutions you came up with!


Edited by Nils Valkenborgh, 09 December 2014 - 01:12 PM.

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