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Monday, January 13, 2020

The Frankenstein monster, my current imaging setup


First time at this Winter season 2019-20 I have a clear sky and somehow functional imaging system.
I managed to mate Apogee Alta U16 + filter wheel with my old second hand Tokina AT-x 300mm f2.8 camera lens.
Lots of self made mechanical tweaks was needed to make this work out.. (I used even an angle grinder to cut off ”unnecessary” parts of the lens to have correct back focus distance)

The result looks more like a Frankenstein monster. It’s alive!!!


"New" imaging setup


Apogee Alta U16 with a filter wheel and Tokina AT-x f2.8 camera lens n th 10-micron 1000 mount. 






The focusing system is build around the TCF-s focuser. Focusing is done by a spring loaded round metal file over the focusing ring. This is a very accurate autofocusing system and it's temperature compensating too.




Shortening the lens, bajonet and aperture control ring are removed and I'm just about to cutting off the filter holder area.  The current imaging system is kind of crazy combination. Actually it shouldn't work at all but with a angle grinder and self made adapter I was able to mate Tokina AT-x 300mm f2.8 optics to Apogee Alta U16 camera and filter wheel. There is also a temp compensating focusing system made from TCF-s focuser, L-shape metal from an old table, round metal file and a spring from an old desk lamp. The CCD is very large, over 36 x 36 mm but for some reason the lens can lit the whole area with a very little coma at most outer corners. 




Self made adapter for the Apogee filter wheel attached.



Original untouched lens.


First light photo for this system


First light image, IC 1396. Since the Apogee Alta U16 has a very large square CCD, the Tokina lens has a very hard time to draw good stars at very outer corners. The system is very picky about he correct back focus distance and the tilt since the critical focus zone at f2.8 is just over 10 metric microns. I did crop out narrow zones from left and right to have perfect star shapes over the area.



Image analysis with CCDinspector
Click for a large image

This works way better than I thought! The whole oversize CCD is lit, there are some coma at corners but it'll be easy to crop out by removing narrow areas from left and right or from up and bottom.

Image of the full uncropped frame 
(reduced 50% due to large size) 





2 comments:

Eko said...

Ompa tosiaa oikea hirviö.
Tekee hienoa jälkeä....
Minä kuvailen tuota avaruutta sellaisilla pikku-hirviöillä....
https://eskoalamaunu.blogspot.com/2020/01/taivaalta-kuvattua.html
Teveisin
Eko Kuusamosta

J-P Metsavainio said...

Hienoa työtä olet tehnyt!

Kirkkaita kelejä,
J-P