

















Why Purchase from All-Star Telescope?
Free Expert Support
Whether you are a first timer needing help with setting up or an enthusiast that can't quite make that one thing work, our expert staff are ready to support your needs. With decades of knowledge and first hand experience we've been there and we can help you through it!
Stress Free, Secure Transactions
You can trust purchasing and delivery with All-Star Telescope. All of our transactions are 100% secure and Level 1 PCI DSS compliant thanks to Shopify's ShopPay platform. For additional protection, we insure 100% of the value of every shipment we make. If it get's lost during shipment, we replace it. If it gets damaged during shipment, we repalce it. We make sure your product arrives exactly as you would expect it to; we promise.
We also ensure privacy protection. We never keep any of your credit card information on file and any of your personal data is stored accordign to our policies.
30 Day Return Policy
Buy with confidence knowing that we accept returns up to 30 days after purchase. We want you to have something you will actually use and we are confident that we keep good quality products in our store with No Junk.
Price Match Promise
Shipping around for the best price is tough, we make it easier by offering the best pricing in the market. But if you find a better price on an in-store item somewhere else we will match it!
Recommended Accessories

iOptron SkyGuider-Pro [SGP] w/ iPolar (3550A)

ZWO ASI2600MC Pro USB 3.0 Colour Cooled Ca...
These are extraordinary cameras. Incredible detail and sensitivity combined with huge sensors result in gorgeous wide-field images. They also work ...

ZWO ASI2600MC Pro USB 3.0 Colour Cooled Camera (ASI2600MC-P)

ZWO Filter Drawer for 2" Mounted Filter (Z...
Filter drawers are the simplest way to improve your astrophotography. Whether you're adding a light pollution filter, or a premium performance narr...

ZWO Filter Drawer for 2" Mounted Filter (ZWO-FD-M54-II)

Optolong L-Ultimate Dual-Band 3nm Filter 2...

ZWO ASIAIR MINI (ZWO-ASIAIR-MINI)
The ZWO ASIair mini keeps almost all the performance of the larger plus while reducing size and cost by considerable margins. These are fantastic c...

ZWO ASIAIR MINI (ZWO-ASIAIR-MINI)

ZWO EAF 5V Electronic Automatic Focuser (Z...
The ZWO electronic auto focuser (EAF) is sure to improve your astrophotography sessions with pin-point stars. It's a great little package that can ...

ZWO EAF 5V Electronic Automatic Focuser (ZWO-EAF-5V)

Pegasus Astro Pulley and Timing Belt for M...
Why we love the William Optics RedCat 51 II APO Petzval OTA (L-RC51II)
Product Description
Designed to be the best, affordable, small, lightweight and fast Apochromatic refactor for astrophotography. The unique optical design includes the highest quality glass for the best possible color correction and flat large image circle. The result is a 51 mm objective lens, in a sleek Petzval design, for a full-frame image.




What can I see with a William Optics RedCat 51 II APO Petzval OTA (L-RC51II)?
Here are some simulated views of common objects. Results with your telescope will vary with viewing conditions, obrits, equipment and more.
Jupiter with
25mm Eyepiece - 10x Magnification
(Sold Separately)
Jupiter with
10mm Eyepiece - 25x Magnification
Sold Separately
Jupiter with
5mm Eyepiece - 50x Magnification
Sold Separately
Moon with 25mm Eyepiece
10x Magnification
(Sold Separately)
Moon with 10mm Eyepiece
25x Magnification
Sold Separately
Moon with 5mm Eyepiece
50x Magnification
Sold Separately
Andromeda with 36mm Eyepiece
7x Magnification
Sold Separately
Andromeda with 25mm Eyepiece
10x Magnification
(Sold Separately)
Andromeda with 10mm Eyepiece
25x Magnification
Sold Separately
What's in the Box
Specifications
Focal Length: | 250mm |
Diameter: | 51mm |
Aperture: | f/4.9 |
Camera Format: | APC-C Full Frame |
Focuser: | Manual Helical Focuser |
Image Circle: | > Full Frame |
Tube Length: | 225mm (Fully Retracted) 305mm (Fully Extended) |
Tube Weight: | 1.8 kg |
Interchangeable T-Mount: | Canon EF Nikon F Sony E Pentax Micro Four Thirds Fuji |



