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View Full Version here: : New William Optics 71mm f/4.9 APO


MortonH
19-02-2014, 09:32 PM
Stumbled across this tonight. One for the imagers.

http://agenaastro.com/william-optics-star71-71mm-apo-imaging-refractor.html

Camelopardalis
19-02-2014, 10:09 PM
Oooo sounds nice, 5 elements and FPL-53 :thumbsup:

MrB
20-02-2014, 02:16 AM
Hmmm, would be nice to see the 100% version of the example photo taken thru it.
WO also have a 5 element 81mm FPL-53 scope (GTF-81) for the same price.
Extra 10mm aperture, tho at f5.9 : http://www.williamoptics.com/wo_shop/index.php?route=product/product&path=21_58&product_id=660

But the 348mm fl of the 71 would suit my Astrotrac nicely as an ultra-portable imaging rig.
Would end up approx. $1300 to my door...
Hmmmmm :confuse3:

AG Hybrid
20-02-2014, 09:20 AM
Morton. Buy one so I can look through it. Do IT!

MortonH
20-02-2014, 10:21 AM
Well, it's not even available until April at the earliest, and I'm not an imager, so no!

Dunk, on the other hand, might want to upgrade his ZS71...:P

Steffen
20-02-2014, 11:15 AM
Hm, so this is what people would use for imaging?

I've got a 75mm f/4 lying around that I might try for that. It has 8 elements (two of them ED) in 6 groups, built-in filter drawer, and full-frame sensors snap right onto it (provided they have a F-mount ;) ).

Cheers
Steffen.

Camelopardalis
20-02-2014, 01:10 PM
I bring my ZS71 with me almost every time but it doesn't get used as much as it deserves...but winter is coming :D That 6 degree FOV will no doubt get used...just nudge any time if you want to look see.

From my experience with the f/6 version, I wouldn't hesitate for a second if I had a good use for it. They don't really show the focuser area, so it's hard to tell if it'd take a 2" diagonal :confused2:

However, I do have the reducer/flattener for my existing one (it came as a bundle) which would take it down to f/4.7...just haven't figured out how to mate the thread with a diagonal :question:

acropolite
20-02-2014, 01:23 PM
A touch wider than the ED80 with f/r (510mm vs 348mm) would make a nice compliment good sensor coverage and hopefully flat field.

David Niven
24-02-2014, 11:54 PM
This is the The WO Zenith Star 71 f/5.9 with a Flat III which turn it into a f/4.8?

Visionary
09-11-2015, 05:44 PM
The postman.... post-per-sibling today delivered a very shiny William Optics Zenith Star 71 f5.9 this unit was supplied with the updated DDG Focuser.
The Focuser is of rack & pinion design and it's built, seriously built. I would go as far to say this is the most stable Focuser I have ever used.
The standard Focuser is rated around 4kg, the DDG is at least 4kg or even more. The way the Focuser moves under load needs to be felt to be appreciated.
I secured the unit at $670 Aust it's an incredible bargain at $670. This is a little scope with a very low centre of gravity... in your hands it feels a million dollars.
This unit belongs to the "red" series and has 2ED elements. I have a very strong feeling that this scope.... telephoto is going to be seeing a lot of use. The 10-1 DDG rack and pinion is truely extraordinary, I have never felt such a beautifully smooth Focuser, 4kg + through 5kg would be my guess, the thing is a rock!