The ridged focusing knobs are easy to turn, even with gloves on, and the 10:1 microfocusing dial allows for very small changes, or tweaks, in focus. The fan is powered by a eight (8) AA batteries (not included) which are housed in an external battery pack.Ī 3.3" dual-speed Crayford-style focuser rounds out this package. The inside of the OTA is painted in a matte black finish, which stops stray light in its tracks.Ī low vibration cooling fan is built into the primary mirror cell of the telescope to assist in cooling your optics down quickly. Steel is a bit heavier than traditional aluminum, but since it has a lower coefficient of thermal expansion, your telescope will tend to hold its shape (and therefore, hold focus) as temperatures fluctuate throughout the night. The ends of the tube are die-cast aluminum, which contribute to the OTA's rigidity. The optical tube assembly on the 3rd Planet Optics Imaging Newtonian telescope is made of rolled steel and painted white. The diagonal mirror is held in place with a thin four-vane spider. Collimation is made even easier due to the center spot marked on the primary mirror. The primary mirror cell is very sturdy, and has six collimation knobs that can be adjusted by hand with a push or pull of the knob. A 91% aluminum coating is applied, and then over-coated with a layer of quartz for the ultimate in durability. The mirrors are made from B270 white water optical crown glass, which is more thermally stable than glass traditionally used on other reflectors. The optics on all TPO Imaging Newtonians consist of a parabolic primary mirror and an elliptical secondary, or diagonal. Image with a DSLR or small webcam all the way up to large sensor CCD cameras with these inexpensive yet effective Newtonians.
If you are looking for a telescope that does a great job of imaging but doesn't come with the cost of a Ritchey-Chretien, check out the Third Planet Optics (TPO) Imaging Newtonian line of telescopes! All of our Imaging Newtonian optical tube assemblies, offered in apertures from 6" - 12", have very fast optics for the widest fields possible.
0 kommentar(er)
