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William Optics Zenithstar 73 ED APO With 50mm Guidescope & Altair GPCAM v2

Price:  £865.00 (Inc. 20% VAT)Earn 865 Loyalty Points

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Generally In Stock, Please Confirm Before Ordering  

Generally In Stock, Please Confirm Before Ordering

Model:  A-Z73RD-M-G50
Brand:  William Optics

William Optics Zenithstar 73 ED APO With 50mm Guidescope & Altair GPCAM v2
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William Optics Zenithstar 73 ED APO With 50mm Guidescope & Altair GPCAM v2William Optics Zenithstar 73 ED APO With 50mm Guidescope & Altair GPCAM v2William Optics Zenithstar 73 ED APO With 50mm Guidescope & Altair GPCAM v2

Rother Valley Optics have put together an imaging rig consisting of the incredibly popular William Optics Zenithstar 73 ED APO superbly paired with the William Optics 50mm guidescope, finished off with the Altair GPCAM v2 Mono guide camera. A perfect imaging set up all equipped for guiding immediately. This kit is in the red colour, but we can do kits with any of the other colours at the same price. Please enquire for more details. 

Full specification of the individual items are below.

William Optics Zenithstar 73 ED APO.

This is the brand new William Optics Zenithstar 73 APO. This superb new scope features an air spaced doublet lens with fully multi coated optics and a Japanese Ohara FPL-53 ED glass element. Thanks to these high quality elements, this will provide very high contrast and sharp views virtually free from any false colour.

The ideal telescope for wide field, high resolution astrophotography and also visual work. The fast f/5.9 focal ratio and compact size makes it the perfect grab and go scope too.

Comes complete with mounting rings, guiding rings and vixen style dovetail bar.

Quality CNC machines aliminium for that luxury finish.

Dual speed 2.5" Rack & Pinion Focuser With 1:10 Reduction.

Refractable dew shield.

New matching anodized tube rings.

Available in a choice of Gold, Blue or Red.

William Optics 50mm Guidescope.

A unique, straight high-quality fully multi coated WO 50mm f/4 Guiding scope that fits perfectly on your William Optics and other telescopes. It's 5.7 deg. of field paired with illuminated reticle will make finding that faint star a cinch.

Both straight and angle finderscopes have a tube diameter of 54mm and dewshiled of 58mm.

• Guiding scope gives sharpest image and straight through viewing with an inverted image.
• Angle version is fully correct image.
• High-quality 50 mm objective.
• 5.7 deg field of view.

Nice Fit & Finish
• Straight and angle versions are compatible with same body.
• 1.25" Helical focusers can accept all standard 1.25" eyepieces.
• White Powder painted.
• Nylon head screws.

• 50 degree 23mm fully multicoated crosshair eyepiece and illuminator can be purchased separately.

Perfectly suited for large SCTs or any William Optics refractor.

Guide Scope Weight: 270g
Optional Rings & Bracket Weight: 430g

Altair GPCAM v2 Mono Guide Camera.

The Altair GPCAM2 AR0130 Mono camera has the sought after Aptina AR0130 CMOS sensor, with higher sensitivity of about 78% QE.

Very high sensitivity in the far red / NIR region makes the GPCAM2 AR0130 especially good for solar imaging with the Daystar Quark other Hydrogen Alpha filters. This high red sensitivity makes it a great choice for Astro Video or EAA use.

The form factor is ideal for the Daystar Quark. GPCAM fits direct to the Daystar Interference Eliminator and the 1.25" nosepiece screws into the other side, which goes into the Quark. Simple and easy to use. Keep it assembled and just pop it in and go!

Onboard buffering gives USB data transfer speeds significantly higher than the GPCAM1 series, pushing the USB2.0 format to the limit, yet within a stable envelope. This almost completely eliminates dropped frames, corrupted video, and enables faster more consistent frame rates, even with less powerful notebook computers.

The GPCAM2 AR0130 Mono camera can be used for any type of imaging you care to try, such as solar, planetary, lunar “lucky” imaging, and even long exposure deepsky photography. Of course video astronomy is easy with the incredible sensitivity of approx. 78% QE. Time-lapse all-sky imaging (with the optional meteor lens) is fully supported in both AltairCapture and SharpCap software.

The camera has an ST4 auto-guiding port, and can be used to auto-guide with mounts from all the major manufacturers supporting ST4 format, such as iOptron, Celestron and Skywatcher.

You would be hard-pressed to find a more versatile small-format colour astronomy imaging camera with this price and features. And what's more, you get UK/EU based warranty support, plus the Altair Camera Google User Group for all your technical questions - a great place to share tips and techniques to get the best out of your camera.

The GPCAM cameras can be fully controlled in AltairCapture and SharpCap to output uncompressed .AVI and .SER video files for solar system "lucky" imaging, as well as all common still image formats such as .JPEG .PNG .TIF .BMP, to mention just a few. The GPCAM supports 8bit or 12bit output. The 12 bit output mode can be used for deep sky imaging with less frames needing to be stacked and a wider pixel intensity range, or for high dynamic range solar and lunar imaging where bit depth improves tonal range. The AR0130 sensor is extremely sensitive in the NIR region and can be used very effectively with IR Pass filters such as the Altair Planet Killer series, for solar and lunar imaging in mono mode. Simply attach the IR pass filter to the front of the 1.25" nosepiece.

What’s different about the "Purple casing" GPCAM2 platform compared to the blue casing GPCAM1 platform? You’ll notice the GPCAM2 casing is larger than the GPCAM. This is to house larger electronics boards which support trigger mode and frame buffering as well as to increase the surface area for cooling. The GPCAM2 platform supports “Trigger Mode” to make long exposures of over 5 seconds easier to control. With most cameras, in normal video mode, you have to wait for an exposure to complete before the camera will accept, say a command to abort the frame, for say clouds, aircraft, or an alignment issue, like kicking the tripod and so-on, or for routine changes in gain, exposure time, , re-aligning or refocusing on the object. For long exposures, normal video mode is inconvenient, especially for video astronomy and deep-sky imaging, however in Trigger mode, you can stop the camera instantly (even if you are half way through a long 30 second exposure) change the settings, and re-start the camera looping again. The GPCAM2 also has an improved onboard frame buffer to improve data transfer stability at high frame rates (to reduce dropped frames) and to increase compatibility with a wider range of PCs. The improved buffers give a more consistent data transfer rate over USB2.0 and USB3.0 buses on laptops and desktop PCs.

Some interesting features of the AR0130 Mono sensor, aside from increased overall sensitivity compares to the MT9M034 sensor in the GPCAM1, is a very high response in the red region of the spectrum making the camera very sensitive to red light for Hydrogen Alpha solar imaging and in the NIR / IR region which enables the camera to be used with an Altair Planet Killer IR Pass filter for high contrast lunar imaging.

Included in the box:

Camera body.
2m High-speed USB2.0 A male to B male cable.
1.5m ST4 guide cable.
1.25 inch x 20mm nosepiece with female 1.25" filter thread on the front.
CS-Mount adapter with built-in Clear Optical Window, AR coatings. (Attached at factory but removable).
Plastic dust cap 1.25".

Camera body.
2m High-speed USB2.0 A male to B male cable.
1.5m ST4 guide cable.
1.25 inch x 20mm nosepiece with female 1.25" filter thread on the front.
CS-Mount adapter with built-in Clear Optical Window, AR coatings. (Attached at factory but removable).
CS-Mount adapter with built-in UV-IR Blocking Filter, AR coated. (Removable).
Plastic dust cap 1.25".
2.1mm F1.6 150 degree FOV wide angle Meteor lens and dust caps.
C-Mount 5mm extension adapter for C-Mount lenses requiring 17.5mm back-focus.
Please note: This camera does not come with software in the box. To operate the camera you will need to download the latest camera drivers at

Sensor & performance specifications:

Sensor Size: 1/3" (4.8x3.6mm)
Exposure duration shortest/longest:
0.115ms (0.000115 secs) / 800 secs (trigger mode)
0.115ms (0.000115 secs) / 5000ms (5 secs) (video mode)
Bit depth: 8bit & 12bit mode switchable
Pixel size microns: 3.75x3.75 um
Resolution in pixels: 1280x960
Recording System: Still Picture and Video
Region of Interest (ROI) support: Yes, in SharpCap & AltairCapture
Approx. Max frame rates (assuming computer Bus and Hard Drive operating at full bandwidth)*:
8 bit mode:
1280x960 - 27-30fps
640x480 - 55fps ROI mode
320x240 - 104fps ROI mode
12 bit mode - approx 50% of above.
* Based on average user reports. May be revised with more data. Shorter exposure durations yield faster frame rates. An expensive PC does not guarantee a fast frame rate.
Sensor QE / Quantum Efficiency: Approx. 78%
Gain Sensitivity: 6.5V/ lux-sec
Dynamic Range: 82dB
SNR Maximum: 44dB
Readout: Progressive Scan
Shutter: Electronic Rolling Shutter

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