SV135 fully multi-coated zoom plossl eyepiece zooms to any focal length between 7 mm and 21 mm - pick the better magnification for your subject. As a beginner; SV135 zoom eyepiece is good for starter astronomer!When you use the SV105 Astronomy Camera with a telescope, you need to adjust the telescope focus wheel while checking the image on your computer for clarity/sharpness.Note: The SV105 Astronomy Camera does not autofocus; you need to adjust the telescope focus to see a clear image.The SV105 camera works with many Windows, Linux, and Android systems.The SV105 Astronomy Camera works with telescopes with focal lengths ranging from 400mm to 800mm, so a refractor telescope with this focal length should see a clear image without any accessories.A tip for beginners: If you are photographing the moon, turn the gain and brightness down a bit, as the moon is closer and brighter. When photographing planets, increase the gain and brightness, as they are much fainter objects.SV155 telescope filter set Red Orange Yellow Green Blue that meets you different needs. CPL Filter: It filters out scattered light, enables you to cut through reflections and see the detail behind it. It tones down the brightness of the lunar surface so you can enjoy optimized contrast of the moon.