| This new SBIG #CFW83 5-position filter wheel comes with a complete four-filter set of 36mm Baader Planetarium LRGB filters. The package price saves you $95 over the cost of buying the filter wheel and filters separately. The filter wheel mounts on the front of the SBIG ST-8300 8.3 megapixel monochrome camera for tri-color imaging with fast focal ratio reflectors and refractors.
Due to the large size of the 3326 x 2504 pixel CCD detector used in the SBIG ST-8300, the typical 1.25" filters in cells that are used with other cameras have a 27mm clear aperture that is too small to fully cover the ST-8300 sensor without vignetting. While this may be acceptable at f/7 or longer focal ratios, at shorter focal ratios the vignetting becomes obtrusive. The 36mm diameter Baader LRGB filters eliminate the possibility of vignetting with a fast focal ratio scope.
The #CFW83 filter wheel is a single carousel design with a new filter retaining system that makes changing filters easier than using individual retaining screws for each filter. An optional second filter carousel is also available so you can quickly swap between the standard LRGB set and a narrowband filter set all as a unit without having to mount and dismount individual filters.
This thin design filter wheel requires only 20mm of back focus, so that the total back focus for an ST-8300 with filter wheel is only 38mm. The #CFW83 plugs directly into the I2C port on the SBIG ST-8300 camera and does not require separate power or control cables. Fully automatic functioning of the filter wheel is controlled by the same software that controls the camera. An optional Nikon lens adapter (#CFW83NIK) is available that connects to the filter wheel to let you use Nikon 35mm and DSLR lenses for extremely wide field imaging.
The 36mm unmounted Baader Planetarium LRGB filters in this package have a peak transmission of 98% in each of the color pass bands. Equal exposure times may be used for all three colors for easier image reduction using a single length dark frame. Each filter is made using a striae-free substrate and optically polished to 1/4 wave p-v flatness over the filter surface, plane parallel to within 30 seconds of arc, for exceptional image quality. The durable multi-layer plasma assisted hard dielectric coatings are ion beam hardened using the latest technology so that the coatings are actually harder than the glass substrate itself to give you a lifetime of use. Unlike other more-delicate filters, the Baader LRGB filters can be cleaned routinely to maintain peak optical performance.
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