72ed woes and The Double Cluster

[alacant]

Hi everyone

A pristine 72ed landed on the bench and looked in perfect repair, Three issues; focuser, astigmatism, tilt 

We removed the 4 rubber -mainly split, hardened and distorted- 'o' rings- from the focuser, loosened the lens collar of the objective cell, rattled it about a bit and then tightened until the rattle of the lenses just disappeared. That was two out of three major issues fixed.

The tilt was a little more difficult and without a reliable laser, resorted to taking flat frames whilst wiggling the shiny collar. It worked quite well.

 

 

 

 

 

 

From tilt city:

... to something which is reasonable;

Waiting for m45 to reach imageable altitude, someone suggested we tested on this. Oh, and I finally realised the official intended purpose of the mysterious black cup which is supplied with all SkyWatcher telescopes and which is normally used to take tots of coñac on cold nights whilst imaging.

Thanks for looking and do post your low end sw refractor experiences.

apilado siril 1.3.0a, procesado st 1.9.558, ~90m

 

Edited October 25, 2023 by alacant
Spell

[Stuart1971]

That’s a very interesting way of adjusting for tilt, using flat frames…so can I ask, the first image you show with the two dark corners in the upper half of the image, does that indicate the tilt, and then the second image was after it was corrected….?

‘I ask because my images come out with two darker corners on one side while the rest of the image is fairly uniform bright….similar to yours 

[alacant]

1 hour ago, Stuart1971 said:

second image was after it was corrected….?

Hi, yes. As you describe. 

If flat fields are correcting ok, then you may as well leave it. Only adjust if star shapes are being affected.

If you have a collimated laser, it may be easier to use that in the focuser to align, but hey, either method takes only a few minutes.

 

Edited October 18, 2023 by alacant