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Can't get into focus with ASA OK3


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#1 wkrispler

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Posted 07 May 2017 - 05:46 PM

Hi,

 

I wanted to test my new ASA setup during daylight. As described in the OK3 manual I attached the extension tube to the focuser and then the Wynne Corrector and my DSLR (see attached image).

I tried values between 0 and 30 in the ACC software (move absolute) but never reached the focus.

 

What is going wrong? Any idea?

Thx,

Wolfgang

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#2 RamaSpaceShip

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Posted 07 May 2017 - 06:06 PM

Hi Wolfgang,

 

As far I can see, it seems that your DSLR sensor is too far away to be in focus. You need to calculate where is the focus plane (using a medium position of the OK3), take into account the back focus of your DSLR and use an extension tube of the appropriate length. You cannot expect to be lucky, and get in focus without this calculation.

 

Best regards.

 

Bernard


Edited by RamaSpaceShip, 07 May 2017 - 06:06 PM.


#3 wkrispler

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Posted 07 May 2017 - 06:09 PM

Hi Bernhard,

 

thank you.

 

I got a tipp from a colleague and removed the rippled extension tube and now it works.

 

Cheers,

 

Wolfgang






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