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William Optics Zenithstar 61 II APO Refractor OTA

William Optics Zenithstar 61 II APO Refractor OTA
William Optics Zenithstar 61 II APO Refractor OTAWilliam Optics Zenithstar 61 II APO Refractor OTAWilliam Optics Zenithstar 61 II APO Refractor OTAWilliam Optics Zenithstar 61 II APO Refractor OTA
Price:  £499.00(Inc. 20% VAT)Earn 499 Loyalty Points

Model:  A-Z61IITG
Brand:  William Optics

2 Year Warranty On All New Items
(Excluding Batteries & Globes)

  (1 Review)

Now complete with soft case as standard

Click here to read the Sky At Night Magazine review of these superb travel refractors. 

We have the brand new 2020 models of these stunning telescopes now complete with William Optics patented bahtinov mask cover! 


The newborn Zenithstar 61II (2020 Model) is the most versatile and portable scope ever made by William Optics. It provides and excellent sharp image with any DSLR for astrophotography or wildlife photography. These telescopes can be used for high power visual work, as well as lunar and solar photography thanks to the dedicated Flattener 61. It is truly a great instrument!

The FPL53 has a significant advantage rather than the older FPL51 (ED). The dispersion properties of the ED and SD glass used in the objective lens are important in determining the overall colour correction. The abbe index is the number used to quantify the "partial dispersion" of a particular glass. The material with the highest partial dispersion is Fluorite at about 95 V and the FPL53 is very very close to pure Fluorite.

FPL53 is the top notch glass material that allows our designer to achieve the best correction possible.

An in house Zygo interferometer test & report is available with this telescope. Click here to read about the interferometer test in more detail. There are various packages available on this model. Please select from the packages above. The optical test and enhance includes a full inspection of the telescope, including optics, focuser, paintwork and other mechanical parts. A precise optical check is then performed then the scope is enhanced to ensure you get the best possible optical performance from your new instrument. 


The interferometer is essentially a measuring instrument. Within the interferometer is a calibrated laser that is pointed through the optical test surface, then onto a high quality reference sphere, then back through the test subject then to an internal camera which gives us the measurement on the screen. From this, we can adjust the position of the test optic and the reference sphere to obtain a perfectly calibrated system. The more central the laser to the test optic and then on return, the better and more accurate reading and measurement we can take. This takes a lot of adjustment to get the best results from the optical surface. Once the measurement has been taken, we are provided with a series of results that show the optical quality of the surface plus other information. We will aim to provide 0.95 Strehl or higher. 

Average Rating (1 Review):  
Write a Review and share your opinions!

Stunning piece of equipment
Wednesday, 5 February 2020  | 

This scope is so well manufactured and presented. The attention to detail and build quality is exceptional for the money and quite refreshing in an 'entry level model'. Solid build, silky smooth operation and good looks all combine to give a feeling of a company that has gone the extra mile to deliver the best they can. The associated case is well worth the money too. I also added the Flat 61 field flattener and it too is beautifully made. I've not challenged the combination optically that much yet on account of poor weather but if the physical build quality is anything to go by then it should be spot on. I'll revert back when I have a bit more use under my belt. I also bought the WO dec adapter, WO saddle plate and WO Vixen plate as upgrades for the iOptron Skyguider Pro and all these are also superbly made. Rother Valley ordering, supply and customer services and support was also superb throughout.

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Some items that are showing as in stock are in stock at our holding warehouses, not at the shop. To double check the stock levels at the shop, please contact us on 01909774369 or

The delivery times for most items is 1 - 2 days but again, please double check stock levels on important orders before placing an order via the website.

The delivery costs for courier next day are for mainland UK only. If you live in the Scottish Highlands/Islands, Channel Islands or Northern Ireland, then a shipping surchage will apply. please contact us for prices. Smaller items can still go 1st class via Royal Mail.

Please note that if you are wanting to take advantage of our Saturday and Sunday timed services or next day pre 12 or pre 10:30 services, you MUST check that the stock is here at the shop before placing orders. Also, orders using the Saturday and Sunday services must be placed before 1pm the previous working day. Also, please remember to check that the stock is here at the shop before placing orders. If the stock is not at the shop, we won't be able to ship on any of the timed services. 

Please note International customers will need to contact us for a shipping price prior to ordering via the website. We don't ship all items internationally. It is at our discretion what we ship outside of the UK. This all depends on the size and weight of the items. Please get in touch with us for any postage costs. Please note we do NOT ship telescopes or heavy items outside of the UK. This is due to massive postage costs and problems regarding returns.

If you have any questions regarding stock levels or delivery, please get in touch.

Rother Valley Optics now have a loyalty point scheme active on the website. As you can see from the products, every item has a point value. Each pound you spend with us, you will receive 1 loyalty point. 1 point is worth 1p. You can accumulate these points as you shop with us, then when you are over £5, you can spend them on the website! Easy as that.

Even if you collect most of your items from our shop, you can still order via the website and select the "shop collection" delivery option. Then you can come to our shop, collect your item and still get your points!

Please note this scheme is online only. Customers who order via the telephone can still be added to the scheme manually. Please ask for more details on this. Before placing orders online, please make sure you are registered with us first otherwise your points won't be allocated.

So happy shopping and if you have any questions about the scheme or any other queries, please get in touch.

Rother Valley Optics


Finance is now available on most products above £250! We offer 12, 24, 36 and 48 months with a fixed 15.9% typical APR. Please note this can't be done through the website at this moment in time. You will need to email us or drop into the shop to sort out finance. As long as the item is above £250, finance is generally available!

Please note some items are NOT eligible for finance. Please contact us for eligibility first. 

Please get in touch with us today to find out if you're applicable.

You must be over 18 years to apply, live in the UK, have a valid UK bank account and not be bankrupt. Your credit file will be searched on application to see if you are eligible.

Rother Valley Optics Ltd is registered in England and Wales 04762707. Registered Office: 21 Station Road, Kiveton Park, Rotherham, S26 6QP. Rother Valley Optics Ltd acts as a credit broker only. Rother Valley Optics Ltd are authorised and regulated by the Financial Conducts Authority. Credit provided subject to age and status..

If you have any questions about this, simply give us a ring or drop into the shop for a chat.

- - - Rother Valley Optics Ltd

01909 774 369