William Optics GuideStar61 61mm f/5.9 Doublet Apo Refractor / Guidescope with Soft Case - Red
This item is discontinued by the manufacturer and is no longer available.
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Important note: As of May 2024, the optional FLAT-GS61 field flattener made for this guidescope has been discontinued by William Optics. Hence, buy this item only if you intend to use it as a guidescope or as an occasionally visual telescope as explained below. Please do not purchase this item for imaging applications only. It will NOT work with the flattener sold for the GS61 telescope so please do not buy that item either to use with this guidescope.
New from William Optics - a simpler guidescope version of their very popular Z61 telescope! It features the same excellent optics and build as the Z61, but in a basic, lightweight housing.
Simpler Focusing Mechanism
The conventional focuser in the Z61 has been replaced by a rotatable 2" drawtube that you can slide in or out manually over a range of 60mm for coarse focusing. Fine focusing is accomplished by rotating the dewshield and locking it in place as is done on many finderscopes. The dewshield can be adjusted over a distance of 25mm.
Mounting the Guidescope
The bottom of the GS61 features a narrow Vixen/Synta-style finder dovetail rail (32mm wide x 120mm long). This is designed to fit into the Saddle/handlebar found on William Optics scopes or in other compatible finder bases. Note that this finder rail is much narrower than Vixen-style mount rails, so you cannot attach this guidescope directly to larger Vixen mount saddles. The top features a Vixen-style handle/saddlebar.
Imaging with the Guidescope
Since this is optically the same as the William Optics Z61 telescope, it provides a full-frame image circle. To attach your guide camera directly to the guidescope, you will require it to have a 2" nosepiece. For use as a primary imaging scope, the use of the optional FLAT-GS61 field flattener is highly recommended. Since the GS61 terminates in a male M48 thread, you will need a camera-specific 48mm wide T ring (sold separately)
Using the Guidescope Visually
As a telescope for visual use, this guidescope can be used with a 1.25" diagonal (you will also need a 2"-1.25" adapter that is not included) and it will be able to reach focus with many eyepieces. However, it cannot reach focus if a 2" diagonal is used.
This guidescope is available in a choice of 3 colors. Also included with each guidescope is a free soft case.
Specifications:
- Focal Length: 360mm
- Diameter: 61mm
- Aperture: f/5.9
- Camera Format: APS-C, Full Frame
- Image Circle: Full Frame
- Recommended Flattener (sold separately): Flat GS61A
- Tube Length: 340mm
- Tube Weight: 3.17 lb (1.44kg)
Other Information
- Country of Manufacture: Taiwan
New from William Optics - a simpler guidescope version of their very popular Z61 telescope! It features the same excellent optics and build as the Z61, but in a basic, lightweight housing.
Simpler Focusing Mechanism
The conventional focuser in the Z61 has been replaced by a rotatable 2" drawtube that you can slide in or out manually over a range of 60mm for coarse focusing. Fine focusing is accomplished by rotating the dewshield and locking it in place as is done on many finderscopes. The dewshield can be adjusted over a distance of 25mm.
Mounting the Guidescope
The bottom of the GS61 features a narrow Vixen/Synta-style finder dovetail rail (32mm wide x 120mm long). This is designed to fit into the Saddle/handlebar found on William Optics scopes or in other compatible finder bases. Note that this finder rail is much narrower than Vixen-style mount rails, so you cannot attach this guidescope directly to larger Vixen mount saddles. The top features a Vixen-style handle/saddlebar.
Imaging with the Guidescope
Since this is optically the same as the William Optics Z61 telescope, it provides a full-frame image circle. To attach your guide camera directly to the guidescope, you will require it to have a 2" nosepiece. For use as a primary imaging scope, the use of the optional FLAT-GS61 field flattener is highly recommended. Since the GS61 terminates in a male M48 thread, you will need a camera-specific 48mm wide T ring (sold separately)
Using the Guidescope Visually
As a telescope for visual use, this guidescope can be used with a 1.25" diagonal (you will also need a 2"-1.25" adapter that is not included) and it will be able to reach focus with many eyepieces. However, it cannot reach focus if a 2" diagonal is used.
This guidescope is available in a choice of 3 colors. Also included with each guidescope is a free soft case.
Specifications:
- Focal Length: 360mm
- Diameter: 61mm
- Aperture: f/5.9
- Camera Format: APS-C, Full Frame
- Image Circle: Full Frame
- Recommended Flattener (sold separately): Flat GS61A
- Tube Length: 340mm
- Tube Weight: 3.17 lb (1.44kg)
Important note: As of May 2024, the optional FLAT-GS61 field flattener made for this guidescope has been discontinued by William Optics. Hence, buy this item only if you intend to use it as a guidescope or as an occasionally visual telescope as explained below. Please do not purchase this item for imaging applications only. It will NOT work with the flattener sold for the GS61 telescope so please do not buy that item either to use with this guidescope.
New from William Optics - a simpler guidescope version of their very popular Z61 telescope! It features the same excellent optics and build as the Z61, but in a basic, lightweight housing.
Simpler Focusing Mechanism
The conventional focuser in the Z61 has been replaced by a rotatable 2" drawtube that you can slide in or out manually over a range of 60mm for coarse focusing. Fine focusing is accomplished by rotating the dewshield and locking it in place as is done on many finderscopes. The dewshield can be adjusted over a distance of 25mm.
Mounting the Guidescope
The bottom of the GS61 features a narrow Vixen/Synta-style finder dovetail rail (32mm wide x 120mm long). This is designed to fit into the Saddle/handlebar found on William Optics scopes or in other compatible finder bases. Note that this finder rail is much narrower than Vixen-style mount rails, so you cannot attach this guidescope directly to larger Vixen mount saddles. The top features a Vixen-style handle/saddlebar.
Imaging with the Guidescope
Since this is optically the same as the William Optics Z61 telescope, it provides a full-frame image circle. To attach your guide camera directly to the guidescope, you will require it to have a 2" nosepiece. For use as a primary imaging scope, the use of the optional FLAT-GS61 field flattener is highly recommended. Since the GS61 terminates in a male M48 thread, you will need a camera-specific 48mm wide T ring (sold separately)
Using the Guidescope Visually
As a telescope for visual use, this guidescope can be used with a 1.25" diagonal (you will also need a 2"-1.25" adapter that is not included) and it will be able to reach focus with many eyepieces. However, it cannot reach focus if a 2" diagonal is used.
This guidescope is available in a choice of 3 colors. Also included with each guidescope is a free soft case.
Specifications:
- Focal Length: 360mm
- Diameter: 61mm
- Aperture: f/5.9
- Camera Format: APS-C, Full Frame
- Image Circle: Full Frame
- Recommended Flattener (sold separately): Flat GS61A
- Tube Length: 340mm
- Tube Weight: 3.17 lb (1.44kg)
Other Information
- Country of Manufacture: Taiwan