William Optics Star 71mm APO f/4.9 Refractor Telescope w/ Rings and Dovetail
"This is the best imaging scope we ever built" says William Optics founder and CEO, William Yang, in describing this new apochromatic refractor.
In addition to utilizing the highest quality FPL-53 fluorite glass, five elements are configured in three groups- a unique, patented 3-1-1 design- not the conventional objective/flattener/reducer design, that affords pinpoint stars from edge to edge covering a 45mm full frame imaging circle-- an astrophotographer's dream especially since this little jewel of a telescope includes a robust 2.5" dual speed rack and pinion focuser that even incorporates a temperature gauge. The drawtube terminates in male M48 thread to which a wide M48-Canon EOS adapter ring (included) can be attached.
This is not a conventional 2" focuser tube with locking thumbscrews. For those wishing to use this very portable telescope as a visual instrument, an optional 1.25" 90 degree dielectric mirror diagonal is available separately. The diagonal comes with a custom adapter that connects directly to the telescope. (Please note: standard 1.25" diagonals are not compatible with this scope which also will not reach focus with larger 2" diagonals.
The CNC-machined optical tube assembly, that weighs no more than six pounds, is finished in William Optics traditional pristine white with gold trim.
- Additional Information
SKU WO-A-STAR71 Manufacturer William Optics Telescope Series William Optics Star Optical Design Refractor - Apochromatic Mount Type None - Optical Tube Only Warranty 1 Year Warranty Telescope Aperture 71mm Telescope Focal Length 348mm Telescope Focal Ratio f/4.9 Tube Color or Finish Gloss White Dew Shield Included? Yes Finder Included None Focuser Size 2.5" Focuser Style Rack & Pinion Manual or Electronic Focusing? Manual Focusing Speeds Two-Speed Total Telescope Weight 6.2 pounds
Customer Reviews 1 item(s)
- Quality and Service is amazing!
I purchased this Star71 from OPT and have to say it came highly recommended for astrophotography and doing more wide field shots. I have not been able to use it yet but the quality of it is amazing! Todd at OPT has been nothing but amazing and helpful with every purchase and will continue to do business with him for a long time.
1= Houston, We Have a Problem & 5= It's Out of This World
- Included Items
- William Optics 71mm Star Refractor OTA
- Mounting Rings
- Vixen Style Dovetail
- M48 Canon EOS Adapter Ring
- Questions & Answers
Product QuestionsQuestion by: Bob on May 24, 2015 8:51:00 AMQuestion by: johnc on May 27, 2014 10:19:41 AMGiven that the telescope will not reach focus with a standard 1.25" diagonal, the usable back focus is probably less than 70mm, which means a Canon DSLR (44mm) with the M48 T-ring (11mm) would have the focuser racked out less than 15mm from minimum.Answer by: Chris (Admin) on May 27, 2014 12:27:15 PMCan you supply the optional diagonal for this telescope?
Do you have a part number and price for it?Question by: Charles Lamb on Aug 19, 2015 1:49:00 PMYes! We do not yet have it listed on the website, but our reference for it is WO-D-125D-WO71, with a price of $119. Please give us a call or email firstname.lastname@example.org if you would like to order. We do have them in stock currently.Answer by: Eric Blackhurst (Admin) on Aug 19, 2015 4:51:00 PMAre there any Optec motor focusers that work with this? Would like to use a DSLR/motor focuser on this for automated imaging runs with Sequence Generator Pro.Question by: Mike Rogers on Jan 19, 2016 7:12:00 AMUnfortunately, no. At the moment, there are no third party motor add-ons that will work with the Star71. Robofocus is a possible option, but you would need to take measurements of the focuser drive shaft in order for them to figure out the correct coupling and brackets needed. Please contact us if you have any questions.Answer by: Chris Hendren on Jan 19, 2016 6:07:00 PMQuestion by: Todd on Dec 8, 2015 11:53:00 AMThe Star71 already has a flat field with its 5 element optical design, and there is not enough additional back focus to allow a focal reducer. This is a camera-ready astrograph and does not need additional optics to be used to its full potential photographically.Answer by: Chris Hendren on Dec 8, 2015 6:37:00 PMIs the William Optics 90-degree diagonal (Item # WO-M-P90) compatible with this scope? Or is there a new diagonal for visual viewing in development?Question by: ScottAz on May 27, 2014 5:07:08 AMThe WO Star71 is a pure Astrograph and is not designed at all for visual use. It is possible to reach focus with a special short-focus 1.25" diagonal, but WO notes these limitations:
This is not a conventional 2" focuser tube with locking thumbscrews. For those wishing to use this very portable telescope as a visual instrument, an optional 1.25" 90 degree dielectric mirror diagonal is available separately. The diagonal comes with a custom adapter that connects directly to the telescope. (Please note: standard 1.25" diagonals are not compatible with this scope which also will not reach focus with larger 2" diagonals.)
For visual applications, the Zenithstar 71 f/5.9 scope would be a better fit.Answer by: Chris (Admin) on May 27, 2014 7:40:48 AMQuestion by: JerryK on Dec 9, 2014 7:17:45 AMAccording to the manufacturer: In addition to utilizing the highest quality FPL-53 fluorite glass, five elements are configured in three groups- a unique, patented 3-1-1 design- not the conventional objective/flattener/reducer design, that affords pinpoint stars from edge to edge covering a 45mm full frame imaging circle.
Given that a full frame DSLR sensor has a diagonal of 43.6mm, it will work fine for that size sensor.Answer by: Chris (Admin) on Dec 9, 2014 10:26:17 AMWould this scope be able to do eyepiece projection with the Baader Hyperion Zoom eyepiece (with or without its barlow attachment)? If so, what adapters would be necessary to mount the eyepiece?Question by: Gavin on Aug 9, 2015 9:03:00 AMThe Star71 was designed as a pure astrograph - meaning that it was not intended to attach eyepieces to this scope. You may be able to focus if you use a Vixen T to 2" adapter http://www.optcorp.com/vixen-t-thread-to-2inch-adapter-for-flip-mirror-diagonal-37292.html and the M48 to T2 adapter http://www.optcorp.com/m48-to-t2-adapter-male-to-male-thread.html, but there is no 100% guarantee that this will focus. If it does, you then need a Baader M43 to T2 adapter and a t-thread spacer or two between the eyepiece and your camera.Answer by: Chris Hendren (Admin) on Aug 10, 2015 5:19:00 PMDoes this scope accept Orion manual filter wheel with Baader Filters, and a Canon 60Da camera? Can focus be achieved in this setup?Question by: Robe on Sep 20, 2014 10:41:33 AMThis telescope has 66mm.4 of back focus from the male M48 threads to the focal plane. A Canon 60Da has a back focus of 44mm and a standard T-ring is 11mm, leaving only 11mm for the filter wheel (which is not possible). Even when using a Teleskop Service short M42 EOS T ring at 2.5mm thick, you only have 19.5mm and the Orion filter wheel is at least 22-25mm thick depending on the attachment method. It would not reach infinity focus.Answer by: Chris (Admin) on Sep 22, 2014 10:29:50 AMIs it suitable to use with STL 11000 +AOL unit ? backfocus,imaging circle,lifting capacity of focuser?Question by: Jose Mundo on Jan 19, 2015 9:06:43 AMPossibly, but it would require custom adapters and you would have no way to rotate the camera. The STL-11000 + AOL combo takes up a minimum of 74mm of back focus with the 5 position wheel and 3mm thick filters. The default back focus of the Star71 is 71.3mm, but if you remove the camera rotator from the focuser you get a female M65x1 thread with a back focus of 92.9mm (see the PDF diagram here: http://www.williamoptics.com/telescopes/images/WO-STAR%2071%20BACK%20FOCUS(20141029).pdf)
The imaging circle of the scope is 45mm, and the sensor on the STL-11000 has a diagonal of 43.6mm, meaning that the images will not be fully corrected and probably vignetted somewhat on the guide CCD. This could make triggering the AO-L fast enough difficult.
William Optics does not state a capacity, but the focuser can probably lift around 3-4kg, so the STL-11000 and AO-L is at the maximum limit. Focus shift or tilt may occur if the focuser is extended too far. The camera and AO-L together weigh more than the whole telescope, so balance will be an issue even if focus tilt is not.
The biggest issue is that the AO-L is really not very useful for a camera with 9 micron pixels much below 1000mm of focal length. It would not make the stars sharper as you would already be at 5.3 arcsec per pixel resolution and any night with seeing worse than that would have such bad conditions that imaging would not be fun. Taking off the AO-L would make this system work better, would save a lot of weight, let you keep the rotator, and only a small custom adapter would be needed to the scope. Balance would still be tricky on some mounts without a longer dovetail, but it could be done.Answer by: Chris (Admin) on Jan 20, 2015 12:24:53 PM
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