The new Astro-Tech AT60GS 60mm guidescope with upgraded helical focuser makes highly accurate autoguiding of deep space astrophotos affordable for any astrophotographer. The Astro-Tech AT60GS 60mm fast focal ratio guidescope adds 10mm of aperture to its 50mm predecessor to allow guiding on fainter stars, plus a new rock-solid upgraded helical focuser to eliminate any possible play in the focuser over its entire travel range.
The Astro-Tech AT60GS guidescope refractor is superb for guiding long-exposure DSLR and CCD astrophotos. It is usable with refractors and imaging Newtonians up to 1500mm in focal length, as well as longer focal length scopes, such as the 12" Astro-Tech Ritchey-Chrétien astrographs.
Taking deep space photos used to require tedious and error-prone manual guiding through a crosshair eyepiece and a large aperture, long focal length guidescope. However, the guiding accuracy of modern CCD autoguiders allows hands-free automatic guiding of long exposure photos through smaller guidescopes with much shorter focal lengths. Using an optically "fast" guidescope, such as the 60mm Astro-Tech AT60GS, you save valuable time, space, and money, while still recording the pin-point star images that only autoguiding can bring to long-exposure astrophotos.
The Astro-Tech AT60GS guidescope is a 60mm aperture 240mm focal length (f/4) achromatic refractor with a helical focuser. The focuser can rotate as well to help you get the perfect framing. It has dual mounting rings with nylon-tipped collimation screws (three per ring). The rings are attached to a riser block that uses a standard Vixen style mounting foot. A vixen mounting shoe is included as well. Add an optional small-chip CCD autoguider, and you ready for automatic guiding.
The Astro-Tech AT60GS guidescope weighs only 20 ounces (30 ounces with the mounting rings and dovetail mounting bar). Its light weight lets you replace a heavier guidescope to gain a little breathing room with imaging setups that are pushing your mount's payload capacity. It measures 10.2" (259mm) long with the focuser collapsed. With the focuser fully extended it measures 10.75" long. A 48mm long fixed dew shield (with rubber dust cover) shields the fully multicoated cemented doublet lens from stray light.
The Astro-Tech guidescope's helical focuser has a lock on the rotation for your CCD autoguider during focusing. The helical focuser simply moves the attached autoguider in or out while maintaining its set orientation. This ensures that the field of potential guide stars will not rotate when focusing.
The focuser drawtube also has a lock on it so you can't accidentally change focuser during your guiding session.
The focuser terminates in a 1.25" accessory holder for those guiders that have a fixed 1.25" nose piece for connecting guider to guidescope. There are also male T-threads for a more solid and secure direct attachment of a guider whose nose piece can be removed to expose female T-threads for attachment to a guidescope.
