There are a number of things that you will thoroughly enjoy as an owner of this "Alstar 1.25" 8-24mm Zoom Eyepiece" which is specifically designed for both visual and photographic use. This high quality 8 to 24mm range zoom eyepiece comes well equipped to suit the demands and ease of use of the amateur astronomer. Equipped with a generous 40° to 60° field of view and a non-click stop adjustment mechanism, this eyepiece allows smooth transitioning between focal lengths, ensuring that the observer can find the perfect combination of field of view and magnification that the target object and seeing conditions will allow. Eyeglass wearers will also find that this eyepiece's long 15mm to 18mm eye relief combined with a flip down rubber eye guard ensures that even they can easily take advantage of the many benefits provided by this eyepiece's high quality multi-coated optics and zoom capability. The single feature that sets this zoom eyepiece above all others is its unique adaptability for eyepiece projection photography. The eyepiece is threaded at the top for a T-adapter (standard M42x0.75 male thread) and at the bottom for 1.25” filters (standard M28.5x0.6 female thread), enabling owners of any T-thread mountable camera to photograph the planets, the moon and high powered terrestrial targets at broad range of focal lengths! In addition to your D/SLR camera, you will require a T-ring for your camera (not included) to use this feature. Featuring a multi-coated optical design, this eyepiece will be providing high contrast views and unparalleled ease of use whether it be for photography or visual observing, for years to come.