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Sharpstar 2.5" Flatteer issues

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#1 vk2gom

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Posted 12 April 2021 - 11:49 AM

I bought a Sharpstar 2.5" Flattener to use with my Altair 102mm f7 (712mm according to a plate solve!) triplet refractor.
 
Setting it up at the correct spacing with my ASI294MC Pro camera, the stars are anything but 'sharp'. I have attached images of both coming to focus with the flattener in place, and coming to focus without the flattener in place from near the centre of the frame.
 
I cannot re-iterate enough, the spacing is correct. I have:

6.5mm      to ASI294 sensor from camera body face
11mm       ZWO coupling ring
21mm       ZWO filter drawer
16.5mm    ZWO spacer
 
= 55mm total
 
then 36.5mm from Sharpstar flattener to endface of M48 adaptor
 
55mm + 36.5m = 91.5mm TOTAL

 

With Flattener.jpg

 

Without Flattener.jpg

 

The supplier is kindly sending me another one to try in the meantime.

 

Any thoughts?

Regards,

Rob.


Edited by vk2gom, 12 April 2021 - 11:50 AM.


#2 PirateMike

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Posted 12 April 2021 - 12:52 PM

How are you focusing the scope?

 

 

Miguel   8-)

 

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#3 vk2gom

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Posted 12 April 2021 - 01:15 PM

How are you focusing the scope?

 

 

 

At the moment with the focuser knob on the focuser, 10:1 reduction, and watching a HFD monitor to achieve best focus. 

 

...why?

 

Regards,

Rob.



#4 vk2gom

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Posted 17 April 2021 - 12:11 PM

New Flattener supplied by retailer, perfect results.

For some reason, the first one I received was a dud!

Regards,

Rob


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