Celestron AstroFI 130 Reflector

[AdyB]

Hi Guys, Just new to the site but not to asltrophotograpy . I have shot loads of times with the DSLR and using a star tracker and have had some rewarding result. I have a problem now........I bought a Celestron AstroFI 130 Reflector but I can't get enough back focus to allow me to focus correctly, does anyone have a solution to the issue I'm having???? Thanks in advance,

[happy-kat]

Welcome.

You could try a x2 barlow or move the mirror up the tube though that's more drastic, though I think the mount is an altaz so moves with tiny up down left right movements which will limit exposure length. A mirrorless camera if you already have one might focus ok.

[AdyB]

Thanks Happy-kat tried x2 Barlow.....no joy. I have x5 Barlow and no joy either. Really would like to take some telescope shots ,,,,,,,,disappointing buddy. Is there any other possible way I have SVBONY extender tube would that help used the correct way??

[happy-kat]

Are you sure it is back focus and not inward focus you are running out of?

[AdyB]

Happy-Cat its possibly inward focus (towards telescope  I presume???). Im ok with the camera but still getting used to the telescope jargon. 

[happy-kat]

I had expected it to be inward focus travel and extension tubes don't help there.

[happy-kat]

Wind the focuser all the way in and then use the barlow and then the camera, and slowly wind the focuser out, you may find you get focus.

[AdyB]

Happy Kat this is the fruit of my labour with x2 Barlow fully inwards no better moving out

[happy-kat]

Have you checked your telescopes collimation?

[happy-kat]

I'm assuming you are trying to use your camera in prime focus, the telescope is acting like a large lens?

[AdyB]

Yes, Happy-Kat, the telescope is brand new and out of the box. Im unsure about collimation

[happy-kat]

Have you left the lens on the camera and then tried to focus through the barlow?

a picture of the telescope with your camera connected could help please

Edited March 13, 2020 by happy-kat

[AdyB]

This is the way I connect Happy-Kat via t-mount. I don't think I can connect with lens attached

[Cornelius Varley]

There appears to be some sort of adapter between the camera and the focuser. There is a threaded part on the focuser, this should be a t -thread (M42x0.75). The t-ring on the camera will attach directly to it giving you a bit mote inwards focus.

[AdyB]

Cornelius Varley and Happy Kat I opted to return the telescope and have good or bad went for a CELESTRON AstroFi 102 mm Maksutov-Cassegrain Telescope  have you both any views (excuse the pun!!) on that ?

[happy-kat]

That sounds not a bad move. Nice and compact and good for night and day use (not sun unless using the correct safe equipment)

[happy-kat]

You might want to consider a 32mm eyepiece if at a later date look to get an eyepiece.

A dew shield you could make yourself easily.

[AdyB]

Thank you Happy-Kat for your help and advise over the past number of days. I'll have to wait a few days on delivery, heres hoping I have better luck attaching the cameras this time.

[irandar]

I seem to keep harping on how to use a mirrorless camera instead of a phone to get focus with the  Starsense DX130 and similar reflectors. Just made a short Youtube on the subject. It includes Sony Nex camera only, with Barlow and with eyepiece projection.                                                                              Using a Camera with a Reflector Telescope

https://www.youtube.com/watch?v=kVYoy1TCWjA