Orion’s StarSeeker IV 150mm Reflector (not to be confused with their 150mm Maksutov-Cassegrain) has a number of features that I applaud. However, some of the design elements are questionable, or at least unproven. This being said, it is still a pretty nice telescope.
Note: This same telescope is sold as the Sky-Watcher Star Discovery 150P outside the US, and has the same features and flaws as described in this review – with the exception of including slightly different eyepieces and a Barlow lens.
The Optical Tube Of StarSeeker IV
The StarSeeker IV 150mm Reflector is a 6” f/5 Newtonian with a 750mm focal length. These are fairly common scopes, especially for beginning visual users or astro-imagers. However, the scope deviates from most of the common 6” Newtonians out there in the form of the primary and secondary mirror supports.
The secondary mirror is held in place by a spider made of ABS plastic, with rods instead of spider vanes. On a 4” scope this would be acceptable, but with a 6” f/5 these rods are of such a size that they introduce additional, unnecessary diffraction to the telescope and smear the image slightly more than regular spider vanes, slightly reducing ...