Unlike external guiding arrangements, when using an OAG, the guiding camera and the imaging camera share the field of view of main optical system. If a user’s OTA has a long focal length, and the environment is not ideal, there will often be fewer stars suitable for guiding to be found in the FOV. One way to improve the chance of finding a good guide star is to use a guide camera with a larger sensor. For example, guide cameras like the QHY5III174M or the QHY5III585C have a FOV that is 2-4 times larger than that of smaller cameras typically sold as guiders. This larger FOV naturally allows you to capture more stars, essentially solving the issue of no or few stars available to guide the image.

In order for a large-sensor guide camera to fully perform to its potential in an OAG, a prism large enough to allow illumination of the larger sensor is needed to avoid severe vignetting. The new OAGM/L Pro uses a new wider prism to better accommodate larger sensor guide cameras. The prism size of the standard QHYOAG series is about 8 x 8mm, while QHYOAGM/L Pro is 10 x 14mm.The main purpose of the OAG is to use the same optical path as the main camera. This avoids the problem of differential deflection that can occur when using a separate optical system for guiding. This method provides more accurate guiding and sharper images. QHYOAG includes a precision 1.25-inch helical focuser that accepts the QHY5II and QHY5III cameras. After focusing, you can lock the focus mechanism with thumbscrews.

The QHYOAG Series directly attaches to the camera or filter wheel with six screws, ensuring a solid, parallel and reliable mechanical connection. At the same time, various standard and optional QHY accessories can be used to realize a variety of structural combinations.

Below are some typical connection examples. Now Adapter B1 Kit is included in each package of QHY268M and QHY600M-PH SBFL. Adapter G1 Kit is included in each package of QHY268C and QHY600C-PH SBFL.