Unable to focus (Skywatcher Heritage 150 + ZWO ASI120MM)

[sivy]

Hi folks,

I got a Skywatcher Heritage 150 telesfope for my kid a few years ago. Last week, I borrowed ZWO ASI120MM camera from a friend who had it laying around.

The integration went smoothly:

Unfortunately, with this setup I was unable to focus this setup on infinity ;/ I could not get the sensor (camera) close enough.

As a next step, I did a "stupid" experiment to remove the focusing ring and put the camera directly in the frame:

With this configuration, I was much closer to focusing, but of course I did not have any adjustment possibility. I was just holding everything in place by hand.

Here comes my question: is there any adapter that could be used in my setup to enable me to focus?

 

[Stu]

I would try putting the focusing ring back, and then just not extending the truss fully so you shorten the optical path enough to reach focus.

[Cornelius Varley]

Can you upload the images instead of external links (links not working)

[Stu]

11 minutes ago, Cornelius Varley said:

Can you upload the images instead of external links (links not working)

That’s weird, I could see them earlier but not now.

[Chris]

You just need to drop the truss rods down by about 1cm and re-tighten them to reach focus with a ZWO planetary cam.

I do this often with my Heritage 150p including last night.

EDIT: The helical focuser and lack of tracking can be frustrating for imaging though. 

 

Edited September 26, 2021 by Chris

[Tiny Clanger]

Yep, close the heritage down a little from the click stop, and tighten the locking screws . Not ideal , but it works.

[sivy]

10 hours ago, Stu said:

That’s weird, I could see them earlier but not now.

Hmm, I attached my pictures as part of the post. Links were only to the manufacturers of camera and telescope.  I still see them fine, not sure what else I could do.

Thanks for the hints to shorten the telescope tube. I will try it tonight!

 

[Cornelius Varley]

On 26/09/2021 at 20:01, sivy said:

Hmm, I attached my pictures as part of the post. Links were only to the manufacturers of camera and telescope.  I still see them fine, not sure what else I could do.

Thanks for the hints to shorten the telescope tube. I will try it tonight!

 

The two photos have links to gooleuser.com and probably can only be viewed by you. The rest of us only see this:

 

Try uploading the images directly from you computer rather that inserting a link to a cloud storage.

 

[wobblewing]

How did you get on with this?

 

I recently bought an ASI224MC and did a bit of Jupitering last night with the 150p and a 2x barlow sitting on my homebrew EQ platform (https://www.youtube.com/watch?v=fGdvxtIfSmU).  However, then I tried to get a wider field of view (I realise this isn't a speciality for the 224!) by fitting 0.5x reducer.. I found that I couldn't get focus even with adjusting the truss rods (camera needs to be closer in).. Will have another play with it - was getting late and cold outside!)

 

Thoughts?  Maybe this is not practical which would be a shame as that's what I bought the reducer for 🙂

 

 

Edited November 5, 2021 by wobblewing