Serious astrophotographers know that an off-axis guider is the best way to ensure perfect tracking accuracy over long exposure times. Unlike a separate guide scope, which can never be 100% perfectly aligned with the telescope, the off-axis guider uses the main telescope optics. This means you’ll correct for tracking errors, opto-mechanical errors, and flexure. It’s a difference you can see in your final images, with round, pinpoint stars across the field of view.
But in the past, off-axis guiders were complicated and difficult to use. Celestron has solved those problems with the most user-friendly off-axis guider we’ve seen to date.
What makes this guider different? The massive 12.5mm multi-coated prism. Other off-axis guiders with inferior prisms provided so little light to the autoguider that locating a guide star was challenging and time consuming. This huge prism perfectly intercepts a small portion of the light coming through the telescope optics and deflects it up to your autoguider. Its huge size, fully multicoated optics, and aluminized backing bring in enough light that it’s easy to locate an adequate guide star.
Even though the prism is large, it intercepts light outside of your camera’s imaging circle, so there’s no loss in image quality. You can adjust the exact positioning of the prism to bring it closer to the imaging circle when using smaller sensors like that of a DSLR.
The guider also features a fixed-orientation helical focuser that works perfectly with any autoguider. A smooth adjustment knob makes it easy to bring your guide star into focus without changing or twisting the autoguider camera’s orientation.
The Celestron Off-Axis Guider goes a step beyond most competitors, providing a wide variety of spacers and adapters to ensure you space your camera exactly on your telescope’s focal plane, even accounting for the width of the guider. Other manufacturers don’t provide these spacers, adding cost and complexity to your final setup. Each guider includes an SCT/EdgeHD adapter, female M48, female M42 (t-thread), male M48, male M42 (t-thread), and 3 T-thread spacers.
This elegant solution will allow you to track exposures confidently for minutes at a time while simplifying your overall setup and reducing setup time.