[60 mm]

Never worry about blurry stars again. Get perfect focus for astrophotography every time with a bahtinov focus tool. The tool clips to the exterior of the lens, allowing for easy mounting and dismounting, even in the dark. Removing the mask wont bump your focus ring. Measure the exterior diameter of the lens or dew shield for the best fit. Bahtinovs are easy to use. Before attaching the device, aim your lens or telescope at a bright star and manually adjust the focus of your lens or telescope until it looks close to focus. Then, gently attach the bahtinov. The mask will diffract the light into three spikes. Adjust focus until the middle spike is centered, then carefully remove the mask to begin viewing. This product is NOT a medical device.