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Bresser offers their Messier 4" f/5.9 Achro Refractor Telescope here without a mount or tripod for users who have a platform and want to add this to their options of OTAs. This Messier optical tube assembly (OTA) features an achromatic lens system to virtually eliminate chromatic and spherical aberrations which translates to an immersive distortion-free viewing experience with true color rendition across the entire field of view - especially at the edges. The combination of aperture, aberration-free optics and a fast f/5.9 focal ratio make this telescope ideally suited for astrophotography and astroimaging. This OTA is ideally suited for imaging or viewing near and deep-sky objects such as the Moon, planets, galaxies, and nebulae.
While there is no mount included, a mounting cradle-ring assembly is provided. It clamps over the optical tube and lets the user adjust the orientation and position of the scope relative to the mount to optimize viewing comfort and balancing, while avoiding interference with other equipment. A stainless steel Vixen-style dovetail plate makes it compatible with any alt-az or equatorial mount with a Vixen-style saddle, and a 1/4"-20 stud on the top of the cradle ring assembly enables a camera to be piggybacked onto the scope for wide-field photography.
The scope is equipped with a 2" rack-and-pinion focuser for over-sized eyepieces and accessories, and comes with a 1.25" reducer adapter and a 1.25" 26mm super Plossl eyepiece that yields 23x power on the OTA. The adapter also has integrated T2 mounting threads to enable the use of a user-supplied DSLR-specific T2 ring for astrophotography through the scope.
Focal ratio: f/5.9
Focal length: 600mm
Refractor-style optical design
Achromatic lenses eliminate chromatic and spherical aberrations for true color rendition and without distortion across the entire field of view, especially at the edges
6x30 non-illuminated straight-view finderscope
Requires user-supplied mount and tripod
Vixen-style dovetail mounting plate
Integrated 1/4"-20 piggyback camera mounting screw
Mounting ring cradle enables OTA orientation adjustment relative to mount
Carrying handle for safe set-up and break-down
2" rack-and pinion focuser
26mm super Plossl eyepiece, yields 23x power
2"-to-1.25" eyepiece adapter with integrated T2 threads
90° star diagonal
In the Box
BRESSER Messier 4" f/5.9 Achro Refractor Telescope - OTA Only