ST80 experiments

[Richard N]

It's pouring with rain and so I decided to do some little experiments with my Meade Adventure Scope 80 (ST80). I was curious to see how well collimated it was. To test it I removed the dew shield and inserted a laser collimator into the 1.25 inch port on the focuser. I then stood the scope on a mirror. I did a few checks to make sure that the method was sound (it was) and then looked at the collimation. It was quite good and I did note that it varies throughout the focusser range being best around infinity (good). I then compared two diagonals. They altered the collimation slightly (the two screw fixing is not the best). The additional dispertion noted on the reflected spot was interesting. Both the cheap supplied mirror diagonal and a celestron prism diagonal gave fairly similar results - the prism being perhaps slightly better. I am not sure what I have learned but it passed a pleasant half an hour. Anything else I could do?

Edited August 8, 2021 by Richard N

[John]

The laser collimator test is good to determine that the optical axis of the focuser is aligned with the objective lens - the laser beam should exit through the centre of the objective lens if the alignment is correct.

Once you have done the above, the cheshire eyepiece is a good way to test the tilt of the objective lens:

Probably best not to get too hung up on these tests though !

 

 

[Knighty2112]

In all the refractors I’ve ever owned I’ve never had a call to collimate any of the scopes. On some of them I did upgrade the stock focuser if possible to give better and finer control over focus, but not sure if that’s doable on your scope.

[Tiny Clanger]

2 hours ago, Richard N said:

It's pouring with rain and so I decided to do some little experiments with my Meade Adventure Scope 80 (ST80). I was curious to see how well collimated it was. To test it I removed the dew shield and inserted a laser collimator into the 1.25 inch port on the focuser. I then stood the scope on a mirror. I did a few checks to make sure that the method was sound (it was) and then looked at the collimation. It was quite good and I did note that it varies throughout the focusser range being best around infinity (good). I then compared two diagonals. They altered the collimation slightly (the two screw fixing is not the best). The additional dispertion noted on the reflected spot was interesting. Both the cheap supplied mirror diagonal and a celestron prism diagonal gave fairly similar results - the prism being perhaps slightly better. I am not sure what I have learned but it passed a pleasant half an hour. Anything else I could do?

There's a whole thread dedicated to messing with st80s , you may find some of the cloudy time activity suggestions useful 🙂

Heather

 

 

[Ags]

I have learned a lot from this thread, thanks!