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View Full Version here: : Speers-Waler 5-8mm Zoom

iceman
06-10-2005, 09:05 AM
Does anyone own one of these, or has anyone tried them?

They don't seem to be that common in Australia.

They're made by Antares, and i'm contemplating the 5-8 SW Zoom for my premium planetary eyepiece. The 5-8mm zoom would allow use in average and good seeing, and by all reports, they also barlow very well for use in very good seeing.

Some vital stats:

- 9 (!) element design
- 89-84 deg AFOV
- 12mm ER
- 1.25" barrel

They go for about US$239 or CDN$299 or approx AU$315, not including any shipping, customs or GST charges.

Some more info is on Phil Harrington's site (http://www.philharrington.net/sw35a.htm) if you scroll down.

They are big! (image from Phill Harrington's site)
http://www.philharrington.net/speers3.jpg

Anyone used them?

They'd be a bit cheaper than a televue nagler or radian in the same focal length, and with the zoom you effectively have multiple eyepieces in one.
h0ughy
06-10-2005, 09:12 AM
gee mike you would need a few speaker magnets to balance that! Best of luck tracking one down.
ving
06-10-2005, 10:15 AM
not seen them before mike but I have been looking into the vixen zoom EP... havent seen any reviews tho.
the FOV on that SW is great tho hey :)
mickoking
06-10-2005, 10:47 AM
9 elements, Me thinks thats too many.:D
asimov
06-10-2005, 07:48 PM
9 elements hey? Not to my liking I'm afraid..
iceman
06-10-2005, 07:50 PM
Why not? Please explain..
ving
06-10-2005, 08:07 PM
theres a review for the SW zoom on CN mike... go have a look :)

gtg, the sky becons!
asimov
06-10-2005, 08:41 PM
I don't know......Just what I was taught back in the old days: too many elements = less light transmission. But perhaps these days that 'theory' no longer holds true due to advances in optical design?
Starkler
06-10-2005, 09:31 PM
The issue is that the more glass to air surfaces, the more opportunity for light scatter and ghosting. Coatings will have to be A-1 to prevent ghost images.

One issue I have heard mentioned about this eyepiece is that dirt can easily get inside the slot for the sliding barlow adjuster.

Read user reviews here (http://www.excelsis.com/1.0/entry.php?sectionid=22&entryid=103&PHPSESSID=e5eb6f5feff57596fdcba52b9 b8a503a)
asimov
06-10-2005, 09:38 PM
Interesting......
iceman
07-10-2005, 07:10 AM
There's a review by well respected amateur David Knisley over on CN, here:

http://www.cloudynights.com/item.php?item_id=331&pr=2x7x32
davidpretorius
07-10-2005, 07:48 AM
that is a good recommendation, so mike, will you have the eyepiece at snake valley??
iceman
07-10-2005, 07:58 AM
Unlikely, unfortunately.