If you are considering buying an SBIG ST-i planet cam, consider adding the SBIG ST-i Guiding Kit to your camera order. The Guiding Kit will convert your ST-i camera into a compact, lightweight photoguide system for long exposure astrophotography that can be used with any equatorial mount that accepts an autoguider input. Buying this guiding kit now, at the same time that you buy either ST-i planet cam, will save you some money over the cost of adding it to your planet cam later. The pictures on this page show the STIKIT/ST-i camera combination. For an image of the STIKIT by itself, click here
. This special $300 price does not include the ST-i camera shown in the image above. The camera must be ordered separately (but at the same time as this guiding kit), at the camera's regular price, in order to get this special price on this guiding kit.
The SBIG ST-i Guiding Kit consists of a high quality 100mm focal length f/2.8 lens with locking aperture (f/2.8 to f/22) and focus adjustments, a custom C-mount adapter that connects the autoguider lens to your existing SBIG ST-i color or monochrome imager, custom heavy duty black satin finish rings and a universal mounting plate, plus a lens shade/dew shield that slips over the lens to shield it from unwanted ambient light. The assembled ST-i/Guiding Kit combination is ultra-compact, only 6.5 inches long, and weighs less than 13 ounces (368 grams), including the camera.
The Guiding Kit’s fast f/2.8 lens allows guiding on very faint stars. For example, it is capable of guiding to sub arc second accuracy on stars fainter than 7th magnitude using 1-second exposures. Its large 2.7° x 2.0° field of view means that there will virtually always be a suitable guide star in the field of view, no matter where the telescope is pointed at the sky.
The benefits of this wide field are twofold. First, there is no need to hunt for guide star. Second, since there is no need to adjust the pointing of the guide scope away from the main scope to find suitable guide stars, the guider can be more firmly mounted to avoid differential deflection. Unlike mounting systems using rings with three-point adjustment screws that can move or flex, the oversized rings of this Guiding Kit clamp firmly around the body of the ST-i camera and hold it firmly in place. Guide scopes that use adjustable mounting systems are almost always plagued with differential flexure. In comparison, the ST-i guiding Kit is mechanically rock-solid.
The custom mounting rings and universal base plate of the ST-i Guiding Kit provide multiple attachment options for almost every telescope equipped with a piggyback mount or accessory plate that uses a standard 1/4-20 bolt or threaded hole.
In addition to making guiding a complete and easy task, this Guiding Kit also makes the ST-i a very capable electronic finder scope. The ST-i, with its built-in shutter, can take dark frames allowing the useful capture of relatively long exposures compared to other guiders. The fast f/2.8 focal ratio of the Guiding Kit, combined with the high sensitivity and dark frame capability of the ST-i, means that globular clusters and cores of galaxies are within easy reach of this compact system. In tests of the ST-i and Guiding Kit from a typical backyard observatory with average light pollution, stars dimmer than 10th magnitude were detected in 1-second exposures. In 10 seconds, stars dimmer than 13th magnitude were recorded and stars as dim as 15th magnitude were captured in 30 seconds.