Pentax 8-24mm zoom

[Mr Moff]

Evening everyone. I was just wondering what the Pentax zoom is like compared to the xw range or naglers?

Is it worth the price tag?

Just thinking out loud really.

[E621Keith]

Pentax XL 8-24 zoom is a very good eyepiece, but it is not on the level of premium fixed. The field is narrow, starting from 40deg at 24mm to 60deg at the 8mm end.

Transmission doesn't seems to be as good as my LVW13. However, it's very sharp and shows no CA. The coating is also excellent and shows very little reflection on planets.

All my scopes are F6 or more so I can't tell you how it will perform on a fast dob. Whether it's worth the money is subjective. It's definitely worth the money for me, I bought mine used and it is my most used eyepiece.

However, if you are considering a zoom of XW/Nagler quality, you may have to look at the Leica ASPH zoom instead.

[Doug]

Pentax XL 8-24 zoom is a very good eyepiece, but it is not on the level of premium fixed. The field is narrow, starting from 40deg at 24mm to 60deg at the 8mm end.

Transmission doesn't seems to be as good as my LVW13. However, it's very sharp and shows no CA. The coating is also excellent and shows very little reflection on planets.

All my scopes are F6 or more so I can't tell you how it will perform on a fast dob. Whether it's worth the money is subjective. It's definitely worth the money for me, I bought mine used and it is my most used eyepiece.

However, if you are considering a zoom of XW/Nagler quality, you may have to look at the Leica ASPH zoom instead.

I thought this Leica ASPH zoom was for sporting scope !

[E621Keith]

I thought this Leica ASPH zoom was for sporting scope !

Apparently APM Germany has special adapters for the Leica eyepiece. The Leica ASPH is only zoom I know to have Nagler class 80deg AFOV (@8.9mm). It also has an AFOV of 60deg at the long end, which means it's narrowest AFOV is wider than the widest AFOV of most zoom eyepieces. Also it seems to be very highly regarded by the refractor owners on CN, but it is also said to be a poor performer on fast newt. Personally I've never looked through one and doubt I ever will, especially with its price tag.

APM also sells an adapted Zeiss zoom, which has a widest AFOV of 68deg, but I haven't heard anything about this eyepiece for astro use.