As modern technology is dramatically changing, so is people’s demand for advanced products, the industrial structure of astronomy is unknowingly undergoing an upheaval. Customers are becoming more greedy for astrophotograph since the digital cameras are now more budget-friendly and available for ordinary people. So the future dominant product in the field may be a comprehensive device which can be applied for astrophotograph as well as visual observation.
Responding to the call of the new era, Sharpstar introduces its 61EDPH astrograph. Its aperture is 61mm, and the focal length is 355mm, thus the focal ratio is f/5.5. One of its objective lens is an ED(extra-low dispersion) glass.
The comparatively fast-focal-ratio astrograph is rather compact and lightweight, wrapped with an integrated tube ring that is artistically pierced. Additionally, there is a streamline handle that can function as a base for the attachment of other accessories, and a 10cm dovetail plate.
There is a hole pre-tapped at the center of the dovetail plate, convenient for attachment of a tripod in ground-imaging situations. The 61EDPH is equipped with a 2.5" rack-and-pinion focuser which can be loaded with a dedicated reducer.
Sharpstar also casts a lot of attention to the 2.3" f/4.5 full-frame reducer which is dedicated for 61EDPH. It has M63×1 thread at one end(for connection to the focuser) and M48×0.75 at the other. The back-focus is standard 55mm after a connection of a camera. If not satisfied, users can attach extra spacers(not included) to extend the back-focus up to 99mm.
The reducer features three-element air-spaced lens structure, supporting full-frame imaging, more strictly controlling the vignette at the edge of the image. When cooperating with 61EDPH II, the reducer can effectively shorten the focal length to 275mm, really preferred by experienced deep-sky imagers. Another improvement is that the f/4.5 reducer is also designed with a 360-degree rotator, which is of great convenience for composition when imaging the deep-sky objects.
Application：for Sharpstar 61EDPH
Back-focus：55mm (can be extended to 99mm)
Length：95mm (including the M48 thread)
Coating：full-surface multi-layer coating
Name：Sharpstar 61 EDPH
Tube length：235mm (with dew shield contracted)
Limiting visual magnitude：10.7
Accessories：one tube ring, one dovetail plate, one handle
Tube outer diameter：80mm
Resolution：1.93 arc second
Net weight：1.42kg (without tube ring and dovetail plate)
Objective type：doublet air-spaced APO (including an ED glass)
Gross weight：1.8kg (with tube ring and dovetail plate)
SHARPSTAR 61EDPH + F4.5 full frame reducer：
H 30x 10min