Image shift between EP's

[parallaxerr]

I recently bought a Skywatcher illuminated reticule eyepiece with the intent of improving the GOTO accuracy of my Nexstar SE mount.

It is 1.25" format so I fitted it to my diagonal with the usual adapter, however, when reverting to my Hyperion Zoom with 2" snout, the object that was centred in the reticule EP was considerably off centre.

Has anyone else experienced similar or is this perhaps a known issue that I am not aware of?

[Tinker1947]

This will just be the sloppy fit that comes with the standard fitting, i suspect throwing a large amount of money at it will cure the problem, like  a Moonlight/Feathertouch Focuser and Baader Click Lock fittings........

[parallaxerr]

4 hours ago, Tinker1947 said:

This will just be the sloppy fit that comes with the standard fitting, i suspect throwing a large amount of money at it will cure the problem, like  a Moonlight/Feathertouch Focuser and Baader Click Lock fittings........

My initial thoughts, but I already have a moonlite focuser!?

[Louis D]

Verify the reticule is centered by slightly loosening the retaining screw/clamp and rotating the eyepiece in the holder to see if it remains centered on the star.  If possible, repeat by rotating only the 2" to 1 1/4" adapter.

[bomberbaz]

Is the 1.25 adaptor a self centering type or one with screws or compression rings. Personally I would test each element in the focuser train inc the actual focuser, how well centred in the secondary is it. So on, I did this when I set mine up to confirm collimation of the focuser, also moonlite. I threw a 1.25 adaptor away recently because it was so poor at centering eyepieces.

[parallaxerr]

5 hours ago, Louis D said:

Verify the reticule is centered by slightly loosening the retaining screw/clamp and rotating the eyepiece in the holder to see if it remains centered on the star.  If possible, repeat by rotating only the 2" to 1 1/4" adapter.

 

15 minutes ago, bomberbaz said:

Is the 1.25 adaptor a self centering type or one with screws or compression rings. Personally I would test each element in the focuser train inc the actual focuser, how well centred in the secondary is it. So on, I did this when I set mine up to confirm collimation of the focuser, also moonlite. I threw a 1.25 adaptor away recently because it was so poor at centering eyepieces.

Goid ideas, thanks guys. I have both moonlite and altair astro 1.25" adaptors so will try both and rotate to confirm the reticule us central. Both have compression rings so may be the issue.

[Louis D]

I forgot to mention that if you have a rotating focuser in a newtonian, it is much easier to verify that everything is aligned.  It wouldn't help all that much with a telescope that uses a diagonal.