DESCRIPTION

QSI WSG Upgrade for QSI 500 Series "WS" Cameras (O)

About the QSI Precision Off-Axis Guider...

Selecting the best guiding solution has always required a compromise. The available, integral off-axis guider (OAG) solves many of the problems associated with existing guiding solutions.

The Right Guiding Solution...

Guiding with a separate guide scope provides the most flexibility, but differential flexure can be an issue, especially with long focal length scopes. With an internal guide chip, you're forced to guide with light through your filters and you can't guide at all while the shutter is closed or an image is being downloaded. This is especially problematic for narrowband imagers. To get around those issues, you could add an external off-axis guider, but a traditional OAG can add an inch or more of back focus plus more weight and two new mounting surfaces that need to be held rigidly.

Guide with Light From in Front of the Filter Wheel...

The QSI 500 Series "wsg" models solves the problems with other guiding solutions by integrating a precision off-axis guider directly into the camera body with the pick-off prism positioned in front of the integrated color filter wheel ƒ??????????? right where it belongs.

Never Struggle With Finding a Guide Star...

One of the main challenges when using a camera with an internal guide chip is to find a star bright enough to guide by within the limited field of view of the internal guide sensor. When shooting through red, green or blue filters, two-thirds of the available light is blocked by the filter and not transmitted to the internal guider chip, guaranteeing lower signal-to-noise stars for guiding. This problem is compounded with narrowband filters where as little as 1% of the total light from a star reaches the guide chip. By positioning the pick-off prism in front of the filters, you always have all the star's light available for guiding.

Integrated OAG Supports Fast Optical Systems...

By integrating the off-axis guider into the camera, we're able to position the pick-off prism very close to the internal filter wheel adding minimal backfocus and eliminating any possibility of flexure or rotation compared to a traditional OAG. The large 1/2" square pick-off prism is optimally positioned close to the internal filter wheel, supporting the use of guide cameras with large sensors, while preventing any vignetting of the main sensor even with very fast optical systems.

Flexible Guide Camera Options...

The off-axis guider (OAG) built into 500 Series "wsg" models is designed to support any camera with 12.5mm of back focus or less that can be attached using C-mount or T-mount threads. Many cameras are designed with 12.5mm of back focus to be compatible with CS-mount lenses which use the same thread as C-mount (1" x 32tpi) but with 12.5mm of back focus instead of 17.5mm for C-mount.

Easy, Rigid Guide Camera Focusing...

The guide camera attaches to the "wsg" using a C-mount or T-mount threaded adapter (specified at time of order). The threaded adapter sits on top of the focus ring and allows the guide camera to be rotated to any position. The focus ring threads onto the focus base to allow 3mm of travel when focusing the guide camera. Once focus is achieved, the focus ring is locked with a set screw. The guide camera can still be rotated manually if desired without changing the focus. The end result is a rigid, easily focused guide camera that will not move or flex while your mount tracks the apparent motion of the night sky.

Image shows "wsg" cover attached to a "ws" camera body, which is sold separately.