Eyepiece focus position advice

[MortonH]

I've noticed that Televue eyepieces require more focus out travel than all my other eyepieces.

Anyone know of other brands that are similar in this respect? I need an eyepiece around 20mm that will focus at a similar position (I'm having in-travel issues with my ZS80 and erecting diagonal). Needs to have at least 60 degree field and at least 15mm eye relief (closer to 20mm would be better).

Based on my current collection, I believe that Pentax, Orion Stratus and Burgess/TMB eyepieces are out. Anyone have the 20mm William Optics Swan? Any other contenders? Not willing to spend lots of money since this is for terrestrial viewing and will be a duplicate of my lovely Pentax XL 21mm.

Thanks for any advice.

Morton

[The Warthog]

I picked up a parfocalizing ring at a star party last year, because it was cheap, like me, and tossed it into my kit against future requirements. When I bought my two Antares SWAs, they turned out to be parfocal, but the 4.3mm W70 I bought required a lot of out-travel to focus. I put the parfocalizing ring on the W70, and with a little adjustment I have an ep that is almost perfectly parfocal with the others, leaving only enough tube for the set screw to grasp.

So, that Antares W70 needs a lot of out-travel, and would be a good choice for terrestrial viewing, as it's a good ep for the money. Consider parfocalizing rings if you need to make your set as parfocal as possible.

[iancandler]

Give Ian King a ring and ask if he has an sct thread nosepiece for your diagonal as it brings the whole assembly much closer to the focuser and has helped me with my in travel problems.

[Andrew*]

So you're wanting one around the 20mm mark? I'm just reviewing three at the moment. I almost certainly will note focus position as I also have issues with this.

http://stargazerslounge.com/index.php/topic,19362.0.html

check this space

Andrew