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Sky-Watcher SkyMax-150 / EQ6 Pro mount
Until the arrival of the new SkyMax-150, SkyWatcher offered Maksutov-Cassegrain tube assemblies in apertures of 90, 102 and 127mm. Each of these instruments has garnered praise for its optical quality, t and nish, a tradition continued by the SkyMax-150 Pro with its stunning champagne gold and white trim. This is no lightweight though: the tube assembly and 9x50 nder tip the scales at over 6kg. However, this does of course mean that you get a lot of telescope for your money. The rich, deep green multi-coatings on the 151mm diameter meniscus at the front reveals an aluminised secondary mirror 43mm in diameter (with a 28 per cent central obstruction). A conical bafe tube xed to the rear of the meniscus gives improved light sealing and reduced light scatter. The review instrument proved to be in perfect collimation, but should the need to adjust optical alignment ever arise, the rear cell does have three pairs of Allen-head screws.

Wide focusing range

The visual back eschews a standard SCT-style thread, while the rear aperture of the bafe tube is 24mm in diameter; this is a scope designed for 1.25-inch (31.7mm) diagonals and eyepieces. The SkyMax-150 is focused by moving the primary mirror via a focusing knob on the rear cell in the manner of Schmidt-Cassegrains. This does give a wider focusing range but the penalty is mirror shift, which in this model was in the region of 1 arcminute when changing focus direction. Not surprisingly for a scope of this size and type, it required a cool-down time of about an hour before delivering the best images. Star testing revealed that the optics were smooth and well corrected, with very symmetrical intra- and extrafocal images. Jupiter was a mesmerising sight when seeing permitted. Both pairs of epsilon () Lyrae displayed a clean, single diffraction ring around each of the components, with other stars in the eld; high contrast optics indeed.
The SkyScan Go-To mount is very rigid and imposing; with the tripod, it has a mass approaching 24kg. Add a counterweight and the SkyMax-150 tube assembly, and youre looking at a total close to 35kg. However, the weight is not a problem for this impressively equipped German equatorial: it will carry payloads up to about 22kg for visual use, approximately 18kg for imaging. Like the HEQ5 Pro, I was most impressed by the performance of the new EQ6 Pro. At all slew speeds it was by far the quietest of all those under test and both the Go-To and tracking accuracy were superb. Astrophotographers will be glad to note that it has a built-in auto guider port and trainable period error correction (PEC) via the SkyScan hand control. Tests showed that it is possible to consistently autoguide the EQ6 Pro to an accuracy of better than 6 arcseconds.

VITAL STATS

> PRICE 1,549 > OPTICAL DESIGN Maksutov-Cassegrain > APERTURE 151mm > FOCAL LENGTH 1,800mm, f/12 > GOTO MOUNT German equatorial > GROSS WEIGHT 35kg > MANUFACTURER Sky-Watcher (Synta) > TEL > WEB www.opticalvision.co.uk > FOR Optics and high-spec mount > AGAINST Heavy to set up for one person

VERDICT

VALUE FOR MONEY OPTICS EASE OF USE BUILD QUALITY MOUNT & DRIVES OVERALL

94% 96% 88% 90% 92%

September 2005 BBC Sky at Night

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Sky-Watcher EQ6 Pro SkyScan

VITAL STATS

> PRICE 1,149 > CONNECTOR Vixen-style dovetail > WEIGHT 24kg > LOAD CAPACITY 24kg > MAX SLEWING SPEED 3.4/second > HAND CONTROL DATABASE 13,400+ objects > INTERFACES RS-232; autoguider > POWER SUPPLY 12V external (supplied) > MANUFACTURER Sky-Watcher > TEL > WWW.opticalvision.co.uk > FOR Best for heavy scopes > AGAINST Too heavy to be portable
The Sky-Watcher EQ6 Pro is by far the most substantial mount of the four on test. Like the HEQ5, the EQ6 Pro is a logical development of Syntas popular heavy-duty EQ6. Those who still possess the older version may be interested to hear that a 499 upgrade kit is available from the UK importer, Optical Vision Ltd. This includes a replacement control panel/motor board, two stepper motors and, of course, the SkyScan computerised hand controller. At twice the weight of the Vixen Sphinx mount and tripod even before any
counterweights are added the EQ6 Pro is clearly not for the faint-hearted or weak of limb. While its quite possible to assemble this leviathan and strip it down on your own, it is really a mount that is best suited to a permanent observatory setup. At rst glance it may simply appear to be a scaledup version of the HEQ5 Pro, but there are notable differences. Consider the tripod and its 5cm (2-inch) diameter stainless steel legs: its identical to the Celestron CG-5s. Given that Synta now owns Celestron, perhaps thats not so surprising. The extra mass of the EQ6 mount increases the stability to such an extent that we practically had to thump it to induce any vibrations.
Polar scope is a pleasure

VERDICT

BUILD QUALITY
FEATURES GO-TO ACCURACY TRACKING ACCURACY STABILITY OVERALL

86% 89% 91% 91% 95%

Like the HEQ5 Pro, the built-in polar axis alignment scope is a real plus for the Sky-Watcher range. When the SkyScan is powered-up, a small red LED gently illuminates its objective lens to aid the visibility of the internal reticle, making it so much easier to offset from Polaris to the true north celestial pole. When we inspected the polar scope in detail, we found that it was well aligned with the axis of the mount, to better than 2 arcminutes in fact. It is also adjustable for higher precision if required, making it a real pleasure to use. If the HEQ5 is powerhungry, the EQ6 is a powerdevourer; expect an even shorter time between charges with this mount, although this is not so much of a problem with an observatory setup, where a mains supply can be used. One thing that surprised us was how quiet the EQ6 Pro was, even when operating at its fastest slew speeds. The alignment procedures and capabilities of the version 2.05 SkyScan hand control are identical to that supplied with the HEQ5 Pro, though curiously we found that the tracking accuracy of this larger mount was slightly worse. Periodic error was similar, at around 30 arcseconds before calibration, while Go-To accuracy was identical to that of the HEQ5 Pro. We felt that this, the largest mount offered by Sky-Watcher, caters more for big-scope owners seeking a permanent setup than observers who like to be eet of foot. If the rumours of a ash-upgradeable SkyScan hand control are true, then more features are on the way.
June 2006 BBC Sky at Night 97

Sky13_GTtests_final 5

5/5/06 10:56:56
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