About this product
Part Number: 61EDPH III
Optical Bench Test
At FLO, we check all SharpStar refractor telescopes on our optical bench before dispatch.
This ensures you can be confident your telescope will, from the outset, have well-figured optics, negligible false colour and spherical aberration, and no astigmatism (the bane of any optical system!). Star shapes will be round, not triangular, oval or egg-shaped!
SharpStar 61EDPH III f/5.9 Triplet ED APO Telescope
The 61EDPH III features an air-spaced apochromatic triplet objective with two ED elements.
Sharpstar upgraded the triplet air-spaced APO optical design for this new V III model. It now has two low-dispersion ED glass lenses (its predecessors had one) for enhanced performance.
Sharpstar has also upgraded the handle with a new multifunctional design that can be connected to the universal vixen-style finder base. In addition, the 61EDPH Ⅲ is equipped with a longer 200mm Vixen-type dovetail plate for connection to equatorial mounts and accessories, which makes the OTA easier to balance on the mount.
With a focal length of 360mm and a fast focal ratio of f/5.9, the fully multi-coated optics provide excellent colour correction and image sharpness in a highly compact design.
The internally-blackened aluminium optical tube further enhances the performance by maximising image contrast. The optical tube is 272mm long when the dew shield is retracted.
The 61EDPH III is equipped with a 2.5" dual-speed rack-and-pinion precision focuser. The focuser is fully rotatable by 360 degrees to enable easy framing of targets on the camera sensor.
An optional full-frame reducer and a full-frame flattener are available for the 61EDPH Ⅲ: The back focus is 55mm. One end of the reducer or flattener features an M68 x 1 thread to connect to the focuser drawtube; Camera side, the reducer and flattener features an M48 x .75 thread and has a built-in 2" filter thread. If more back focus distance is required, the reducer and flattener can be split to reveal an M54 × 0.75 male thread, and the back focus then becomes 75mm (Reducer) and 81.5mm (Flattener)
The focuser adopts a quadruplet air-spaced structure, supporting full-frame imaging. With the reducer, the focal ratio of the 61EDPHⅢ reduced to F4.5 and the focal length is reduced to 270mm, and this is considered the best choice for deep sky astrophotography.
With its excellent colour correction, the 61EDPH III also works well for grab-and-go visual astronomy (without the focal reducer).
It is supplied with anodised tube rings, a carrying handle, and a finderscope mounting bracket. It also includes a 1.25”-2” adapter for use with smaller diagonals and eyepieces.
- 61mm Aperture
- f/5.9 focal ratio / 360mm focal length
- f4.5 focal ratio / 275mm focal length with optional Reducer
- 3-element air-spaced APO optics (two ultra-low dispersion ED elements)
- Fully multi-coated optical surfaces
- 2.5" Dual Speed Rack & Pinion Focuser
- 44mm image circle with optional reducer
- OTA weighs only 1.5kg / 1.92kg with rings & dovetail
- 272mm Long with dew shield retracted
What's in the box
- Sharpstar 61EDPH Triplet Apochromatic Refractor
- CNC Tube Ring / Cradle & Handle
- Vixen Compatible Dovetail
- 2" and 1.25" Eyepiece Adaptors
- Finder Shoe
|Aperture ||61mm |
|Focal Ratio ||f/5.9 |
|Focal Length ||360mm |
|Optics ||Triplet air-spaced APO with two ultra-low dispersion ED glass elements |
|Resolution ||1.93 Arc Seconds |
|Limiting Star Magnitude ||10.7 |
|Tube Length ||272mm Retracted |
|Tube Diameter ||75mm |
|OTA Weight ||1.48kg |
|Weight with Rings & Dovetail ||1.92kg |
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