Samyang 135+ filter wheel or drawer + asi6200

Auto-Focusing EAA Troubleshooting
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Vladimir González avatar
Vladimir González avatar
I have a big problem to achieve correct focus. Somebody solve with this setup?
samyang 135 ( for nikon ) + adapter ( zwo ) + filter wheel or drawer ( zwo , usually 20 mm ) + zwo camera asi6200
andrea tasselli avatar
andrea tasselli avatar
F mount lenses require 46.5mm of backfocus. The ASI6200 needs 17.5mm by itself which leaves 29mm to play with. The following adapter/filter drawer from ZWO would do the trick:

https://www.365astronomy.com/zwo-2-filter-drawer-for-nikon-lenses-with-male-m42-connection-for-the-camera?path=160_303

You'd still have 0.5/0.7 mm of extra backfocus to play with, depending on the filter you'd be using. You'd be needing a M54 to M42 female-male adaptor to go with it. There will be still some vignetting I'm afraid. Custom modification of a standarf filter drawer with a M54 back thread is another possibility but isn't in the ZWO catalog. Otherwise you'd need a ASI filter wheel for 2" filters and the following adapter:

https://astronomy-imaging-camera.com/product/nikon-lens-adapter-for-2filter-wheel
Helpful
Carastro avatar
Carastro avatar
Many have problems like this.  I wonder whether this might be your answer, you need to remove the bayonet and screw this to the back of your lens.

https://www.firstlightoptics.com/adapters/astro-essentials-samyang-lens-to-m48-adapter.html

Carole
Vladimir González avatar
Vladimir González avatar
Hi, thanks. It’s a good possibility.
Carastro avatar
Carastro avatar
I should add that you will not find that adapter anywhere else as it was designed by a member of Stargazers Lounge having the same problem as you and made by First Light Optics the sponsors of Stargazers Lounge.  

Carole
Achim Schaller avatar
Achim Schaller avatar
I had a similar problem but Sony e-mount and an ASI 294mm pro and I built my own adaptor:

https://www.cloudynights.com/topic/810468-diy-asi-to-sony-e-mount-adapter-with-filter/

Clear skies,   Achim
andrea tasselli avatar
andrea tasselli avatar
Carastro:
Many have problems like this.  I wonder whether this might be your answer, you need to remove the bayonet and screw this to the back of your lens.

https://www.firstlightoptics.com/adapters/astro-essentials-samyang-lens-to-m48-adapter.html

Carole

That won't work. It is for a Canon fit not a Nikon. You'd need to add a 2.5mm spacer to make it work.
Well Written Concise
Carastro avatar
Carastro avatar
I believe the bayonet gets removed altogether, it certainly fits some of the more modern CMOS cameras, but not sure which since I just know it doesn’t fit my Atik cameras.

The Retailer knows what cameras it will fit. 

Carole
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