The remote guiding head contains a cooled, 16 bit 657x495 TC-237H CCD indentical to internal self-guiding CCD in the STL camera body. The remote head is equipped with t-threads on the front cover and it will accept the eFinder assembly for guiding, a camera lens adapter, a T to C adapter, or the provided 1.25" nosepiece for use with an external guide scope. The external guider will also control the AO-L when used with an off-axis assembly or pellicle splitter.
Now you can add a second head to your ST-7/8/9/10/2000 camera and guide using the internal tracking CCD or the external Remote Guide Head. The single sensor "I" versions of these cameras can also add the remote head for external guiding only. Originally designed for the large format STL cameras, the Remote Guide Head contains a cooled TC-237 CCD with 657 x 495 pixels at 7.4u and 16-bit A/D. This is the same CCD that is used as the built-in tracking CCD on all of our dual sensor, self-guiding cameras. It is also the same sensor used in the stand-alone STV autoguider and the former ST-237 CCD camera. By popular request, we have added support for the STL Remote Guide Head to the ST-7/8/9/10/2000 series (single sensor and dual sensor models) for those who want to put the guiding CCD in front of the filter wheel by way of an off-axis guider, or separate guide scope.
One of the main benefits of using the Remote Guide Head instead of a separate camera for guiding is that no additional power or computer connections are required. The Remote Guide Head gets power and control from the camera and it is controlled just like the internal guider by the same software program that is used to control the camera. Once installed, the user can select either the internal or external guider and all other software functions are essentially identical. Another benefit is that the Remote Guide Head can control both the AO-7 and AO-L adaptive optics units when used in an off-axis guider* placed between the AO and the camera/filter wheel. This allows the AO to be used with any filter in place and the guide star brightness will not be affected. Since the Remote Guide Head is also compatible with upgraded "I" versions of the ST-7/8/9/10/2000 cameras, a wide variety of choices are available to the user when putting together a system. The alternative for external guiding is to use a separate autoguider such as the ST-402ME. These also have advantages in terms of flexibility and independent control but they require their own power supplies and separate cables for computer connections. Separate guiders cannot control the AO units, unless you use the built-in guider in a second ST-7 camera. They will, however, guide continuously while the image downloads from the main camera whereas the Remote Guide Head acts just like the internal guider and pauses during download. However, software allows for automatic resumption of guiding with the Remote Head, including automatic re-acquisition and positioning of the guide star between exposures.
* Note: A custom made off-axis guider is needed to use the remote head to control an AO. We are working on this accessory but it is not yet available from SBIG, although there may be some third party solutions available.