ASI 290MC and TS Optics B1060 Vario Finder scope

philippe

Hello,

I plan to buy very soon an ASI 290 MC color camera after many weeks talking about my needs (deep sky mainly and planetary) with friends on French astronomy forums .

I already have an AZ EQ6 GT Pro with a Sky-Wtcher 200/1000.

My finer scope has been replaced recently by a TS Optics B1060 Vario model :

- https://www.teleskop-express.de/shop/product_info.php/info/p11022_TS-Optics-60mm-Finder---Guide-Scope-with-ED-Objective-and-T2-Connection.html

I would like to know exactly which ring and/or extender I need to use this camera mainly for autoguiding purpose ?

One web shop told me that I only need this reference :

- https://www.teleskop-express.de/shop/product_info.php/language/en/info/p5733_TS-Optics-T2-Verlaengerung-und-Zwischenring---Baulaenge-15-mm.html

Is that right ?

Will I just need to screw this extender on the finder scope and the camera to it and that will be it ?

Is there a risk of wrong backfocus ?

Furthermore, on one of the forums I'm a member of, some people practice "short time shooting sessions", that is they take hundreds of photos of no more than 1 seconds and then use Siril, DSS, and other softwares to stack and process photos.

I would then have to attach the camera to the focuser.

Do I need again something specific ?

Kind regards

Philippe

katherine.tsai

Hi Philippe，

I am not sure about the back focus of your guide scope.

Please confirm the back focus of your guide scope then arranged the adapter.

ASI290 MC provides 7.5mm or 12.5mm back focus.

https://astronomy-imaging-camera.com/product/asi-290mc-color

As it is illustrated in the mechanical drawing on the website.

Do you mean lucky imaging, it is widely used in planetary photography.

philippe

Hi Katherine,

In one of the emails exchanged with the web store, here's the answer provided :

Yes it is the same adapter ring for both cameras. Both cameras have 17,5mm back focus.

They talk about the ASI224 (which was my first theoritical choice) and the ASI 290 MC color of course.

I'm a bit suprised with the figures you mentioned...

They're no beginners and noticed for their fast and professional asnwers to email requests.

Is there a different way to calculate the backfocus ?

For memory, the T2 distance ring suggested is of 15mm .

By the way, you didn't answer the second part of my post, regarding the camera being used attached to the focuser ?

Do I need an adapter / extender / ring ?

Kind regards

Philippe

katherine.tsai

Hi Philippe,

First I would like to apologize that I made a mistake, the back focus og 290MC is 12.5mm, not 7.5mm.

https://astronomy-imaging-camera.com/product/asi-290mc-color

You can see the mechanical drawing from product detail page.

I saw the specification from the technical data and it says: Working distance from the female T2 thread: 57-94 mm

The 290MC has the back focus of 12.5mm and there will need more 44.5mm distance and M42*0.75 male thread. You can buy two 16.5mm extender and one 21mm extender, then add a T2-T2 adapter(2mm), it will give you 68.5mm back focus.

It should be enough.