Can't get anywhere close to focus

[_Belial]

Hi All,

I recently purchased a William Optics Zenithstar 73 II APO, I've got a canon 600D which I'm using prime, I have a t-ring and adaptor and fits into the scope fine, but for the life of me I cannot focus at all. I've tried all the way down the focus wheel and doesn't come anywhere near close to focusing at all. I tried this with the moon and stars, just a blurry mess, am I missing something obvious? I an put my 120M guidecam in fine and it focus' but the 600D won't come close, but the camera itself is fine as I can use the lens and it can focus fine?

Any advice gratefully appreciated.

[Davey-T]

May not have enough back focus travel, try it in the diagonal to see if it focuses.

Dave

[PeterCPC]

...and if it does use an extension tube.

Peter

[andrew s]

You need to find roughly where it is. Use just the scope and point it at a distant outside view, then with no camera or eyepiece find where the image focuses on a bit of white card.

Focuser fully in so you can see the card. This tell you where the chip in the camera needs to be.

Regards Andrew 

[_Belial]

Thank you all so much for that, I'll try again later, thank you.

[rickwayne]

Or, absent a white card, you can just hold the camera behind the telescope and move it back and forth. Don't ding the sensor into the back of the telescope, though -- I can tell you it's hard to look at all the things at once!

[Pompey Monkey]

I fhi k you may need a 35 mm extension: