Photastro "On OTA Mounting Kit"

[dugnsuz (Doug)]

Hi all,
I recently acquired a Canon 70-200mm f4L IS lens with a view to using it as a travel ‘scope’
I’ve had success with that particular lens in the past and I wanted to use it with my 2600MM and 7x36mm filter wheel, and that’s where things started to get complicated.

Canon lenses have a back focus distance of 44mm - the 2600 and EFW added up to 32.5mm. So an EOS-M42 adapter to connect lens to filter wheel/camera of 11.5mm was needed. ZWO do a 11.5mm adapter for the 2" Filter wheel but not my 7x36mm model unfortunately.

The currently available ZWO adapters are larger than 11.5mm, so after much forum diving, I sourced a 10mm adapter and 1.5mm spacer from Teleskop-Express in Germany.

After getting some positive results testing out this setup I wondered how I could attach my ASIAIR and EAF and create a rig!

Google searches yielded a few 3D printed add-ons, but no all in one solution.

Then I discovered the Photastro site - Vladimir Minenko in Germany produces an excellent 3D printed ‘On OTA’ rig for various different lenses, my new Canon 70-200 being one!
All up $260AUD delivered
https://minenko.org/on-ota-mounting-kit/

Yet to test under the stars, but happy so far - unfortunately I’m off O/S soon and clouds are forecast for the next few days leading up to my departure.
So a full test may be a month or so away - the EAF belt turns the focusing ring on the lens smoothly, without any observable backlash - so far,so good!

Anyway, the included pics show the easy construction process and final result.
Might be of interest to some of the imaging brethren

[leon]

Oh, I like that Doug, very interesting and I do have a nive 70-200 Lens which would suit the job.

Thanks for the informative post, and enjoy your trip to where ever you are going.

Leon

[anyabellina364 (MICHAEL)]

Originally Posted by leon

Oh, I like that Doug, very interesting and I do have a nive 70-200 Lens which would suit the job.

Thanks for the informative post, and enjoy your trip to where ever you are going.

Leon

Thanks for the kind words! The 70-200mm lens should work great for what you're planning. Enjoy using it, and safe travels to Doug!

[Ryderscope (Rodney)]

That is very interesting Doug, thanks for posting this information. I’m running an ASI6200 camera with a Canon f2.8 prime lens and have made up my own side by side plate to accomodate a mini guidescope. Whilst this is working quite successfully for now, I will certainly keep this product in mind for future planning.

CS,
Rodney

[dugnsuz (Doug)]

Originally Posted by leon

Oh, I like that Doug, very interesting and I do have a nive 70-200 Lens which would suit the job.

Thanks for the informative post, and enjoy your trip to where ever you are going.

Leon

Originally Posted by anyabellina364

Thanks for the kind words! The 70-200mm lens should work great for what you're planning. Enjoy using it, and safe travels to Doug!

Thanks leon & Michael - off to UK/Europe soon

[dugnsuz (Doug)]

Originally Posted by Ryderscope

That is very interesting Doug, thanks for posting this information. I’m running an ASI6200 camera with a Canon f2.8 prime lens and have made up my own side by side plate to accomodate a mini guidescope. Whilst this is working quite successfully for now, I will certainly keep this product in mind for future planning.

CS,
Rodney

I edited my post after reading your comment Rodney - I recalled that ZWO do produce an 11.5mm EOS-M54 adapter for large format cameras and the 2" EFW.


Do you use a filter wheel with your 6200 and lens?
Doug

[Ryderscope (Rodney)]

Originally Posted by dugnsuz

I edited my post after reading your comment Rodney - I recalled that ZWO do produce an 11.5mm EOS-M54 adapter for large format cameras and the 2" EFW.


Do you use a filter wheel with your 6200 and lens?
Doug

I have the 50mm filter wheel and Astronomik filters. For connection to the lens, I have the adapter from Astro Mechanics. This adapter has the correct back spacing and gives direct control of the focus mechanism in the lens and the aperture control. Astro Mechanics is a Russian firm. I bought mine before the current hostilities.

[dugnsuz (Doug)]

Originally Posted by Ryderscope

I have the 50mm filter wheel and Astronomik filters. For connection to the lens, I have the adapter from Astro Mechanics. This adapter has the correct back spacing and gives direct control of the focus mechanism in the lens and the aperture control. Astro Mechanics is a Russian firm. I bought mine before the current hostilities.

Very nice - I've looked at those Astro Mechanics adapters, but alas it would involve me de-assimilating myself from the Borg, errr ZWO ecosystem

[Leo.G (Leo)]

That looks like a very nice set up Doug. Pity my Nikon lenses aren't as easily focused or zoomed with a toothed belt, they have a cross hatched knurled finish instead of the Canons simple toothed structure. I guess I could always get a toothed rubber ring if I ever wanted to mess around with it.
That wouldn't take up a lot of space in your OS travel luggage I'm guessing so you get beautiful wide field night skies where ever you are?


I've only ever been overseas twice, once to Manly, once to Tasmania.

[dugnsuz (Doug)]

Originally Posted by Leo.G

I've only ever been overseas twice, once to Manly, once to Tasmania.

That travel rig is still a heavy wee beastie, so it'll have to accompany me n' Mrs Doug on caravan trips to Oz dark skies only Leo