With it and my 26mm Tele Vue Nagler eyepiece, the Image 3Įntire payload weighs 33 pounds. The optical tube assembly (OTA) comes with a set of tube rings, a Vixen-style dovetail plate and an 8x50mm right angle finder scope with mounting bracket.Īs shown closer in Image 2, I have swapped out the Vixen-style dovetail plate for a Losmandy-style dovetail plate to use on my Celestron CGEM II mount (see ATT Volume 11, Issue 1). Image 1 shows my newly purchased Sky-Watcher Starlux 190MN, a 190mm f/5.3 Mak-Newt. Finally, the secondary mirror in Mak-Newts is attached to the corrector lens, eliminating the four-vane spider that causes diffraction in standard Newtonians. But this too is minor compared to refractors. Like refractors, then suffer from field curvature. Mak-Newts have one-fourth the coma of straight Newtonians. So Mak-Newts have a meniscus-shaped lens at the end of the optical tube that eliminates this aberration. Spherical mirrors are easier to make than parabolic mirrors, but suffer from spherical aberration. The mirrors are configured like standard Newtonians, except whereas standard Newtonians have a parabolic primary mirror, Mak-Newts use a spherical primary mirror. Mak-Newts are a telescope design that use both a lens and mirrors. This is a 7.5-inch telescope for a fraction of the cost of a 6-inch apo. Mak-Newts are reputed to perform like an apos, at a fraction of the cost for the same aperture size! Fortunately, Sky-Watcher sells a 190mm f/5.3 Mak-Newt for $1500. Then it hit me, I should invest in a Maksutov-Newtonian (Mak-Newt for short) instead. I knew the views would be substantially better than either of my current 6-inch telescopes, but I kept weighing whether the difference is worth an investment tens times greater than my current refractor. Since I haven’t won the lottery, I wasn’t quite sure I wanted to invest that much. Six-inch Apos with high quality glass cost between $6000 and $9000. My refractor has great optics but suffers severely from chromatic aberration since neither element contains ED (Extra-low Dispersion) glass.įor these reasons, I have been considering the purchase of a 6-inch apochromatic (apo) refractor. Stars appear much shaper in the refractor. However, the Newtonian’s mirror does not have the greatest figure.
Both are great instruments for their price. I invested around $300 in the Newtonian and $700 in the refractor.
Sky-Watcher Starlux 190MN Review: I have a 6-inch f/6 Newtonian and a 6-inch f/6.5 achromat refractor that I use entirely for visual use.
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