AstroZap Focus Cap for 6" SCT's
When you want help focusing the image during CCD or DSLR photography sessions, just turn the center knob to the "Open" position to reveal a trio of off-axis masks, just like a simple Bahtinov mask. Moreover, the Astrozap Focus Cap doesn't stop working once focus is achieved. Turn the center knob again to place the cap in the "Closed" position. Then you can either take dark frames or use it as you would any dust cap.
Made proudly in the USA from lightweight aluminum and powder-coated black, this Astrozap Focusing Cap is both strong and will be a helpful astronomical accessory for years to come. Three thumbscrews hold the Focusing Cap firmly in place. No plastic plugs or tools are necessary.
The AZ-423 focus cap will fit telescopes with outside diameters from 180mm-190mm. This measurement is normally that of a 6" SCT, but please measure your own telescope before ordering.