Atik Cameras

Author Topic: Atik filter wheel back focus  (Read 6025 times)

ramv

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Atik filter wheel back focus
« on: May 08, 2012, 09:43:17 pm »
Hi,
I was wondering how much backfocus the atik filter wheel takes up. Specifically I am interested in mounting the Atik 383L+ and EFW-2 on a canon lens. I understand the commercially made lens adapters are too long. Is it possible to even build something here that works?

This is a critical factor for me that will determine whether or not I will purchase an Atik camera in the near future.

Thanks,
--ram
« Last Edit: May 08, 2012, 10:15:53 pm by ramv »

chrisjbaileyuk

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Re: Atik filter wheel back focus
« Reply #1 on: May 09, 2012, 09:33:33 am »
22mm for the EFW2 but you need a bit more for the various thread converters depending on what you are mating to it.

ramv

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Re: Atik filter wheel back focus
« Reply #2 on: May 09, 2012, 04:38:54 pm »
As I understand it, canon lenses have a sensor to flange distance of about 43 mm. 
Looking at the mechanical diagram of the 383 camera, it appears that about 17mm distance between sensor plane and camera flange. So that leaves just 4mm (at best) for an adapter.  Seems possible but wonder if it will be strong enough.

Anybody mounted a canon lens on atik camera with filter wheel?

joelshort

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Re: Atik filter wheel back focus
« Reply #3 on: May 09, 2012, 06:41:38 pm »
I think it would be very difficult to do what you are suggesting, given the back focus.  I doubt you'll be able to find a 4mm adapter that would work, or even to manufacture one would be hard if not impossible.  I recently mounted a cheap minolta lens on my 383L with a custom made adapter.  The lens backfocus is 44.5mm, and I was not able to incorporate the filter wheel into the mix at that short distance.  What I did instead was find an adapter that reduced the front threading of the lens (49mm) down to 1.25" filter threading.  So I can use my Baader 1.25" LRGB filters on the front of the lens.  This is certainly not ideal and I've not tested it out for things like dew formation on the front filter, but I'm optimistic.

If you find a solution in which you can use the filter wheel too, I would love to hear about it.

ramv

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Re: Atik filter wheel back focus
« Reply #4 on: May 09, 2012, 11:14:10 pm »
Hi Joel,
Backfocus of canon lens is similar/slightly less than even Minolta. If you couldn't get the Minolta to work with filter wheel, I dont think there is any chance of being able to mount canon lens on the filter wheel.

Your other idea (use filter with step down rings in front of lens) is an interesting one and will definitely work assuming you can handle the dew issues.
Of course, you are stopping the lens down: depending on the lens it may even be a good idea.

It seems the only other option is to spend the mega bucks purchasing something with an internal wheel (such as QSI). Decisions to make!