72ED Black Diamond Telescope Dual Speed ​​Optical Tube

• Compact, lightweight, Sky-Watcher EvoStar 72ED f/5.8 optical tube only
• Ideal for wide-field deep sky photography or as a second instrument
• Crayford Dual Speed ​​Focus with 10:1 gear ratio
• Comes with clamps, dovetail and hard case.

Sky-Watcher has recently completed its range of apochromatic refractors with the EvoStar 72ED. It is the brand's smallest diameter refractor in ED and is aimed at amateurs looking for an instrument that is as transportable and light as possible . The EvoStar 72ED only weighs 2kg (with collars and dovetail) for a length of 420mm, its spray shield is even removable if necessary (but not retractable). The high optical quality of this model offers everyone the possibility of acquiring a high-performance instrument at a very attractive price for wide-field astrophotography, planetary/solar observation or self-guiding .

To obtain the valuable "APO" designation, a refractor must correct primary and secondary chromatic aberrations , inherent to all systems whose light rays pass through an optical element. In the case of the Sky-Watcher EvoStar 72ED, a doublet formed by an ED glass element reduces chromaticism to significantly limit the appearance of colored edges on planets or the Moon. The ED glass chosen, FPL-53 (Schott) , is the one that can best correct these defects thanks to a very low dispersion (NOTE: this doublet is different from the Black Diamond models).

The use of multi-layer coatings on all surfaces significantly limits losses due to lens crosstalk, making EvoStar 72ED are brighter and more contrasty than conventional, less corrected glasses . The "Metallic High-Transmission" (MHC) treatment is deposited on the air glass surfaces ensuring impressive results ( transmission close to 99.5% ). Thanks to your very short focal ratio, f/5.8 , the Sky-Watcher EvoStar 72ED refractor is particularly interesting for deep sky photography. . In combination, for example, with a large format digital camera (corrector/reducer recommended), point the telescope at large nebulae such as Orion, the Lagoon or the famous Andromeda galaxy.

10:1 Dual Speed ​​Focuser

The focus is obtained through a 2" Crayford focuser (in aluminum) that offers robustness and precision during focus. A clamping screw allows focus to be maintained according to the orientation of the tube. To be consistent with the optics and provide good results in astrophotography (where focus is essential) the EvoStar 72ED focuser has a fine screw 10:1 reduction .

To meet the requirements of amateur astronomers, the optical tube is made entirely of aluminum. No plastic parts used! The solidity is therefore there, as the aesthetics are particularly successful. The interior is blackened and baffled to limit stray light intrusion. A Kodak pitch screw is placed on top of one of the collars to position a camera in parallel.

Specifications

Items delivered

• 1 Sky-Watcher EvoStar 72ED optical tube
• 2 clamps
• 1 Vixen dovetail
• 1 Piggyback mount for Kodak stepper camera on top of one of the clamps
• Rigid suitcase with pre-cut foam