Adjust the brightness level of the Moon, Venus, and other bright objects with the Optolong Variable Polarizer. A standard Moon Filter is similar to a pair of sunglasses. They work fine, but sometimes the scene is too dark or too bright, and there’s not a lot you can do about it. A variable polarizing filter is much more flexible than a Moon filter. It allows you to set the percentage of attenuation by turning the top section of the two-piece filter. Simply attach the 2" threaded filter to a like-sized eyepiece or Astro accessory barrel, and then slowly rotate the top half of the filter—it turns 360°—to achieve the results you desire. The Optolong Variable Polarizing Filter also works great to cut brightness when you are using your telescope for terrestrial observations or photography. If you have ever done photography through a SLR or DSLR camera, you may have already been introduced to the qualities of a polarizing filter, since it is a very popular accessory for polarizing the light and making the sky appear bluer. You will especially appreciate a polarizing filter when viewing over water or photographing a scene that includes a river or body of water. Simply turn the filter until you achieve the most glare-free results—you will really see the difference. 1.25 inch 2 inch Brand Optolong Optolong Type Variable Polarizing Variable Polarizing Substrate Thickness 2mm 2mm Clear Aperture 26mm 44mm Surface Quality 60/40 60/41 Surface parallelism 1/4λ 1/4λ Parallelism 30" 30" Thread M28.5*0.6 M48*0.75 Single Thread Yes Yes
