Televue Paracorr?

Does anyone here own a Televue Paracorr?
Find it any good?

Cheers,

I'd really like to try one on the 20", although I dont think most of the eyepieces would benefit from it.

I've used the Televue Paracorr. In particular at the Newtonian focus at f/4.
The coma does disappear, however, at this f/ratio astigmatism is an inherent problem. I also have had problems with vignetting with the combination of Parracorr and a wide field 31mm Nagler. This would only apply to a steep cone entrance of a large telescope. I got over the problem by enlarging the entrance to the focus holder.

Eamonn A

Eamonn,
Does the position of focus change between just using the eyepiece and using the eyepiece/paracorr combination? I have cut the poles of the truss to suit using my Naglers but am curious about the Paracorr. I don't want to buy one and find that the position of focus is so radically different that I need to get new poles for the truss.
Thanks,

You treat the Paracorr as an eyepiece. ie put the Paracorr into the focus mount, just like an eyepiece, then put the eyepiece into the Paracorr internal tube.

Eamonn A

You treat the Paracorr as an eyepiece. ie put the Paracorr into the focus mount, just like an eyepiece, then put the eyepiece into the Paracorr internal tube.

Eamonn A

Thanks Eamonn. That bit I was aware of.

Say I use my 17mm Nagler and turn the focus knob so that the image comes to focus.
Next, I remove the eyepiece and insert the paracorr with the 17mm Nagler in it. Will I need to change focus from the original position? If so, will I need to turn the focuser by much?

My concern is that at present, the three best eyepieces I have all come to focus. However, if I use a paracorr with the eyepieces, will they all still come to focus, or will I need to modify the telescope in some manner?

Thanks,