Zoom Tab

The Zoom tab provides a close up view of the sky. When the telescope is connected, it also shows a target at the current telescope position.

Along the top is a status display area. The first column shows the position of the current field center, the Field Of View (FOV) of the display (measured top to bottom), and if connected the Position Angle (PA) of the focal plane rotator. The second column shows you the position of the mouse in equatorial and local coordinates. The third column shows information when you click on an object in the display. Please note that you may need to expand the Zoom Tab window to see all of the information presented.

You can move the display by a variety of means. Click and drag on the star field to move the sky. You can use the mouse wheel to zoom in and out, or use the menus. The sky position can also be set from the All Sky Tab and Catalog Tab.

The Snap to Scope button will link the display to the current telescope position. The sky position will move if the telescope is moved. If you move the display manually the Snap to Scope will automatically disable.

The Options menu allows you to control the display:

The Guide Star Catalog should be set up in order to ensure that plenty of stars are available at close-in zoom levels. The GSC is available at http://gsc.dc3.com. It is also available on a memory stick that can be purchased from Diffraction Limited. For fast display it is strongly recommended that the GSC be copied to your hard drive. Both the GSC and TABLES folders are required; point the GSC Location to the folder above these two folders.

The FOV Indicators option allows you to configure overlays indicating the FOV of the camera. You can have several different indicators, but you can only select one for display at a time. To select an overlay, simply turn on the check box beside the Name.

To create a new entry, click New. The FOV Setup dialog appears. Enter a name for FOV Indicator Name. Click the Read Hardware button (if a camera is connected) to enter the Pixel Size X (microns), Pixel Size Y (microns), Pixel Count X, Pixel Count Y, and Focal Length (mm). You can of course enter these values manually if desired. For cameras with integrated guide chips, you can turn on Built-In Guider Chip and enter the equivalent values for the guider. Separation (mm) can be specified as either the distance between the Near Edges of the two sensors (outer edge of main sensor to inner edge of guide sensor), or between the Centers of the two chips; select the method you require using the Measured between control. In either case, the distance is specified in millimeters. (Changing the measurement method will recompute and update the separation if enough information is available to do so.) Click OK to add it to the list.

You can alter an FOV indicator by selecting it on the list and clicking Edit. You can also remove it from the list by clicking Delete. If you have a long list you can resize the dialog by dragging the lower right corner with the mouse. Click OK when you are done.

A right-click menu is also available when the mouse is positioned over the sky display. Many of the Options menu features are available here. There are also additional features:

This allows you to reset the alignment of the telescope mount controller. You have the option of either synchronizing to the catalog object nearest the cursor, or synchronizing to the mouse position on the sky display.

Tip: The best method to align is to use PinPoint Astrometry to measure the exact location of an image from the camera, and then use the Telescope Tab Sync button, which allows you to synchronize to an image PinPoint solution.