Since Stellarvue’s founding more than 20 years ago, optical excellence has been the driving force behind their production of top-tier refracting telescopes. Over the years, Stellarvue has refined their designs and manufacturing techniques, added sophisticated equipment, and trained a corps of master opticians. They currently offer refractors ranging in size from 3 inches to 6 inches. Their largest is the SVX 152T, a 6-inch f/8 apochromatic refractor.
As an astrophotographer, I wanted a telescope that excelled at several things: providing extremely well-corrected optics, easily handling a large 35mm-format camera, and offering a focal length long enough to enable both wide fields of view and relatively high resolution. Because it meets these criteria, I was eager to test Stellarvue’s highly rated SVX 152T.
Unpacking
The SVX 152T ships in a box about the size of a refrigerator and is packed with foam and double-layered cardboard. A robust, hard-sided carrying case with wheels further protects the scope. The case is extremely well made, with riveted aluminum framing around all the edges, and lined with a foam cutout to fit the scope. Twist-locking latches keep the case closed. There are handles on each end to allow two people to easily carry the case, if needed. Inside the case was a user manual and an envelope containing the objective report of the scope, measuring its specific optical quality using the Strehl ratio.
Let’s pause and go over what this number means. The Strehl ratio is one measure of optical excellence used by amateur and professional astronomers alike. A lens or mirror with a Strehl ratio of 1 is theoretically perfect. So, ideally, you want your optics to rate as close to 1 as possible.
These days, machined optics typically reach 0.95 Strehl. If a manufacturer wants to get a mirror or lens with a better value, they’ll need to further refine it by hand, which is a time-consuming art that takes years to perfect. But Stellarvue has reached that higher standard. The SVX line of refractors from 102mm and up all boast hand-figured objectives with a minimum Strehl ratio of 0.99, while the 80mm variants achieve a 0.98 Strehl ratio.
According to the report, my scope measured 0.997 Strehl.