TeleVue Paracorr

[icytailmark]

i decided to buy a televue 20mm type 5 nagler eyepiece for my 12" skywatcher Dob. I was wondering would i need a paracorr to correct coma in my f4.9 telescope?

[wavelandscott]

"Need" is a very strong word...I'd try it without one for a while and see what you think.

I use a Paracorr at f5 and faster and prefer the view even at f5 with the Paracorr...is it necessary, no...I did go for a long time without it. But now that I have it, it rarely leaves the focuser.

[astro744]

Have you used a highly corrected eyepiece in your telescope before? The Nagler 20NT5 is a highly corrected eyepiece and will give you wonderful views with your 12" f4.9 and show you only coma if you look for it and no other aberrations. Any coma you will see is from the primary mirror and not the eyepiece.

Get the eyepiece first and then if you don't like the coma get the Paracorr. General consensus is a Paracorr is useful under f5 but some individuals are bothered by coma more than others.

[icytailmark]

thanks guys ill wait a while before deciding whether or not to buy a paracorr