William Optics ZenithStar 61mm f/5.9 Doublet Apo Refractor with Hard Case - Red
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The William Optics ZenithStar 61 Apo refractor combines superb color-corrected optics, extreme portability, and rock-solid built quality into a versatile telescope for on-the-go visual observation and astrophotography. This little scope is an ideal instrument for wide-field visual sweeps of stars and nebulae along the Milky Way, lunar and solar observation (with an optional solar filter), and daytime nature observation. It also makes a superb astrograph for imagers who wish to take advantage of large-sensor DSLRs and astronomy cameras to capture wide and colorful vistas in the night sky.
The 61mm f/5.9 apochromatic doublet objective in the ZenithStar Apo is made with FPL53 glass with superior dispersive properties and color correction compared to less expensive FPL51 ED glass. The color correction of FPL53 is very close to that of pure fluorite glass, which is why FPL53 is sometimes called ‘synthetic’ fluorite. This glass results in an extremely high degree of color correction, even in a relatively simple and affordable doublet objective.
While the ZenithStar 61 telescope weighs just 1.45kg (3.2 lbs), it has the solid build and high-quality feel common to all William Optics refractors. The beautiful metal tube includes a retractable dew shield and incorporates internal baffled field stops to reduce stray light. Fully retracted, the tube length spans just 230mm, and it's outfitted with a rotatable L-type mounting ring with a short bracket with ¼” and 3/8” holes for mounting onto a solid photo tripod. The bracket also fits into telescope mounts with Vixen-style saddles.
The 2" rack-and-pinion focuser includes a coarse focus knob and a 10:1 fine focus adjustment knob with protective cover. The coarse-focus knob includes a thermometer to help you track temperature changes during your observation sessions so you know when you may need to adjust focus. The focuser has a full 75mm of travel length, a drawtube locking screw with tension adjustment, 1.25" adapter with compression ring, and pre-drilled holes for finders with Vixen-style brackets.
As you might expect with a quality apo refractor, the William Optics ZS 61 is a superb instrument for taking wide-field astrophotos with DSLRs or dedicated astronomy cameras. The scope's optics provide a 41mm-diameter image circle, and with the optional Flat 61 field flattener, a full 43mm image circle to fill the sensor of most any camera.
This package of the William Optics ZenithStar 61 includes the OTA and an airtight carrying plastic hard case. This little scope matches perfectly with a William Optics 2" star diagonal and eyepieces with 5mm to 40mm focal length for visual use.
Useful Resources
- User Manual: William Optics ZenithStar 61 (PDF format, 2.50 MB)
- Z61 telescope review at AstroBackyard.com
- Images taken through Z61 telescope on AstroBin.com
The William Optics ZenithStar 61 Apo refractor combines superb color-corrected optics, extreme portability, and rock-solid built quality into a versatile telescope for on-the-go visual observation and astrophotography. This little scope is an ideal instrument for wide-field visual sweeps of stars and nebulae along the Milky Way, lunar and solar observation (with an optional solar filter), and daytime nature observation. It also makes a superb astrograph for imagers who wish to take advantage of large-sensor DSLRs and astronomy cameras to capture wide and colorful vistas in the night sky.
The 61mm f/5.9 apochromatic doublet objective in the ZenithStar Apo is made with FPL53 glass with superior dispersive properties and color correction compared to less expensive FPL51 ED glass. The color correction of FPL53 is very close to that of pure fluorite glass, which is why FPL53 is sometimes called ‘synthetic’ fluorite. This glass results in an extremely high degree of color correction, even in a relatively simple and affordable doublet objective.
While the ZenithStar 61 telescope weighs just 1.45kg (3.2 lbs), it has the solid build and high-quality feel common to all William Optics refractors. The beautiful metal tube includes a retractable dew shield and incorporates internal baffled field stops to reduce stray light. Fully retracted, the tube length spans just 230mm, and it's outfitted with a rotatable L-type mounting ring with a short bracket with ¼” and 3/8” holes for mounting onto a solid photo tripod. The bracket also fits into telescope mounts with Vixen-style saddles.
The 2" rack-and-pinion focuser includes a coarse focus knob and a 10:1 fine focus adjustment knob with protective cover. The coarse-focus knob includes a thermometer to help you track temperature changes during your observation sessions so you know when you may need to adjust focus. The focuser has a full 75mm of travel length, a drawtube locking screw with tension adjustment, 1.25" adapter with compression ring, and pre-drilled holes for finders with Vixen-style brackets.
As you might expect with a quality apo refractor, the William Optics ZS 61 is a superb instrument for taking wide-field astrophotos with DSLRs or dedicated astronomy cameras. The scope's optics provide a 41mm-diameter image circle, and with the optional Flat 61 field flattener, a full 43mm image circle to fill the sensor of most any camera.
This package of the William Optics ZenithStar 61 includes the OTA and an airtight carrying plastic hard case. This little scope matches perfectly with a William Optics 2" star diagonal and eyepieces with 5mm to 40mm focal length for visual use.
| Manufacturer | William Optics |
|---|
| Aperture | 61mm |
| Focal Ratio | F/5.9 |
| Focal Length | 360 mm |
| Objective Type | Synthetic Fluorite FPL53 Doublet, Air Spaced, APO Fully Multi-Coated, SMC coating |
| Limiting Magnitude | 10 |
| Lens Shade | Retractable |
| Focuser | 50.8mm (2") Rack & Pinion Focuser with 1:10 Dual Speed microfocuser 75 mm (3.2") Focuser Travel Length |
| 1.25" Adapter | Compression Rings |
| L-type Mount | Rotatable L Bracket |
| Field Stops | Baffles |
| Tube Diameter | 93 mm (3.66") |
| Tube Length | 230 mm Fully Retracted 300 mm Fully Extended |
| Tube Weight | 3.19 lbs. (1.45 kg) |
The William Optics ZenithStar 61 Apo refractor combines superb color-corrected optics, extreme portability, and rock-solid built quality into a versatile telescope for on-the-go visual observation and astrophotography. This little scope is an ideal instrument for wide-field visual sweeps of stars and nebulae along the Milky Way, lunar and solar observation (with an optional solar filter), and daytime nature observation. It also makes a superb astrograph for imagers who wish to take advantage of large-sensor DSLRs and astronomy cameras to capture wide and colorful vistas in the night sky.
The 61mm f/5.9 apochromatic doublet objective in the ZenithStar Apo is made with FPL53 glass with superior dispersive properties and color correction compared to less expensive FPL51 ED glass. The color correction of FPL53 is very close to that of pure fluorite glass, which is why FPL53 is sometimes called ‘synthetic’ fluorite. This glass results in an extremely high degree of color correction, even in a relatively simple and affordable doublet objective.
While the ZenithStar 61 telescope weighs just 1.45kg (3.2 lbs), it has the solid build and high-quality feel common to all William Optics refractors. The beautiful metal tube includes a retractable dew shield and incorporates internal baffled field stops to reduce stray light. Fully retracted, the tube length spans just 230mm, and it's outfitted with a rotatable L-type mounting ring with a short bracket with ¼” and 3/8” holes for mounting onto a solid photo tripod. The bracket also fits into telescope mounts with Vixen-style saddles.
The 2" rack-and-pinion focuser includes a coarse focus knob and a 10:1 fine focus adjustment knob with protective cover. The coarse-focus knob includes a thermometer to help you track temperature changes during your observation sessions so you know when you may need to adjust focus. The focuser has a full 75mm of travel length, a drawtube locking screw with tension adjustment, 1.25" adapter with compression ring, and pre-drilled holes for finders with Vixen-style brackets.
As you might expect with a quality apo refractor, the William Optics ZS 61 is a superb instrument for taking wide-field astrophotos with DSLRs or dedicated astronomy cameras. The scope's optics provide a 41mm-diameter image circle, and with the optional Flat 61 field flattener, a full 43mm image circle to fill the sensor of most any camera.
This package of the William Optics ZenithStar 61 includes the OTA and an airtight carrying plastic hard case. This little scope matches perfectly with a William Optics 2" star diagonal and eyepieces with 5mm to 40mm focal length for visual use.
Useful Resources
- User Manual: William Optics ZenithStar 61 (PDF format, 2.50 MB)
- Z61 telescope review at AstroBackyard.com
- Images taken through Z61 telescope on AstroBin.com
| Manufacturer | William Optics |
|---|
| Aperture | 61mm |
| Focal Ratio | F/5.9 |
| Focal Length | 360 mm |
| Objective Type | Synthetic Fluorite FPL53 Doublet, Air Spaced, APO Fully Multi-Coated, SMC coating |
| Limiting Magnitude | 10 |
| Lens Shade | Retractable |
| Focuser | 50.8mm (2") Rack & Pinion Focuser with 1:10 Dual Speed microfocuser 75 mm (3.2") Focuser Travel Length |
| 1.25" Adapter | Compression Rings |
| L-type Mount | Rotatable L Bracket |
| Field Stops | Baffles |
| Tube Diameter | 93 mm (3.66") |
| Tube Length | 230 mm Fully Retracted 300 mm Fully Extended |
| Tube Weight | 3.19 lbs. (1.45 kg) |