William Optics WO-Star71 71mm f/4.9 Apo

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Jonas
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Ort: Kristianstad

William Optics WO-Star71 71mm f/4.9 Apo

Inläggav Jonas » 2014-08-07 10:22:21

Ursäkta att nedanstående recension är skriven på engelska men det beror på att jag även publicerat den på en del internationella fora. Engelska fungerar nog föresten för de flesta här på forumet.

When I was scanning the market for a small lightweight photographic refractor, my attention was drawn to the new astrograph from William Optics.
The Star 71 Astrograph seemed to contain every aspect I was looking for:
- Lightweight (OTA with rings and dovetail only 5.3 lbs / 2.4 kg)
- High optical and build quality (FPL-53 glass, 5 elements in 3 groups)
- Small size (Only around 330 mm / 13 inches long)
- Flat photographic field (Covers 45mm full frame imaging circle!)
- In addition, the focuser is an R&P design which mean there is now risk of slippage during photography and an EOS adapter is included in the delivery.
So I decided to order one from Ganymedes Optics in the Netherlands and received it a couple of days later.

Delivery/unpacking:
The scope arrived in a well foamed cardboard box. This inner box was placed inside a second cardboard box. The packaging felt very secure.

Lifting up the telescope from the box, the feeling of it was that it is very solid. I get a feeling of high quality in every detail of it. Focuser is very distinct as are the rotation of the camera mount. No plastics anywhere and the little gem has the same good looks as all the other white and gold scopes from William Optics.

Photographic tests:
As I had bought this astrograph mainly with a thought as traveling scope in mind, I was of course eager to know how it would work on my Astrotrac with a Canon 5D MkII so this was to be my 1:st test.
Putting the package on the Astrotrac, presented of course no large problems. Just the ordinary balancing issues.
Focusing the astrograph is extremely easy. Just centre a medium strong star in the camera and use LiveView. The focuser (with its 10x reduction) is very exact and have no play. The star is well defined and exact focus very easy to reach. (Easier than on my Canon 300/f:2.8 set at f:4).
There are no visible focus shift when locking the focuser or rotating the camera.

Images:
As I live in the north of Europe, the sky during summer doesn’t really get dark during July and I had to keep the exposure times to a maximum 2 minutes but in my opinion, the imaging quality look promising.
Attached are my first two images together with a picture of the setup used during the evening..
- Double cluster (NGC 869 and NGC 884), 2014-07-22, 8x2 minutes.
- M31, 2014-07-22, 10x1 minutes.
- Astrotrac mounted on a Manfrotto 055B tripod. Canon 5D MkII mounted on the Star 71 astrograph.

Summary:
As you understand from the text above, I am very happy with my Star 71 but there are maybe two issues that could be improved.
I look forward to working with this little gem and see what it can deliver.
Positive:
- Large flat imaging field with pinpoint stars.
- Good and solid mechanics.
- Small and light. (Perfect travel scope!)
Can be improved:
- Too short dew shield. (Especially in my climate, this will need to be solved.)
- I would rather have a M48 to M42 male or M48 to T2 male adapter instead of the Canon adapter. (This would make it easier to connect other imaging equipment).

Best Regards

Jonas Carlsson
Sweden
astrofotografen@gmail.com

My impression coincide very much with Charlie Bracken’s. Read his review here:

http://digitalstars.wordpress.com/2014/ ... refractor/
Bilagor
14-07-22 M31 CFM Small.jpg
14-07-22 M31 CFM Small.jpg (379.68 KiB) Visad 3502 gånger
14-07-22 Double cluster CFA Small.jpg
14-07-22 Double cluster CFA Small.jpg (450.74 KiB) Visad 3502 gånger
Setup Small.jpg
Setup Small.jpg (212.45 KiB) Visad 3502 gånger
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