the finder scope caps on if you leave it attached to the optical tube.

Cleaning the Tube

Your StarMax 90mm EQ telescope requires very little mechanical maintenance. The optical tube is aluminum and has a smooth painted finish that is fairly scratch-resistant. If a scratch does appear on the tube, it will not harm the telescope. If you wish, you may apply some auto touch-up paint to the scratch. Smudges on the tube can be wiped off with a soft cloth and a household cleaner such as Windex or Formula 409.

Cleaning Lenses

Any quality optical lens cleaning tissue and optical lens cleaning fluid specifically designed for multi-coated optics can be used to clean the StarMax’s front meniscus lens or exposed lenses of your eyepieces or finder scope. Never use regular glass cleaner or cleaning fluid designed for eyeglasses. Before cleaning with fluid and tissue, however, blow any loose particles off the lens with a blower bulb or compressed air. Then apply some cleaning fluid to a tissue, never directly on the optics. Wipe the lens gently in a circular motion, then remove any excess fluid with a fresh lens tissue. Oily fingerprints and smudges may be removed using this method. Use caution; rubbing too hard may scratch the lens. For the large surface of the meniscus lens, clean only a small area at a time, using a fresh lens tissue on each area. Never reuse tissues.

10. Specifications

Optical design: Maksutov-Cassegrain

Aperture: 90mm

Effective focal length: 1250mm

Focal ratio: f/13.9

Central obstruction diameter: 29mm

Primary mirror coating: Aluminum with overcoat

Meniscus lens coating: Anti-reflection multi-coatings on both sides of lens

Eyepiece adapter: Accepts 1.25" accessories, camera t- threads

Eyepiece: 25mm Sirius Plössl, fully coated with multi-coatings, 1.25" barrel diameter

Magnification with supplied eyepiece: 50X

Actual field of view with supplied eyepiece: .96°

Diagonal: 90° mirror star diagonal, 1.25"

Finder scope: 6x magnification, 20mm aperture, correct- image, achromatic, 6.2° field

Finder scope bracket: Dovetail base, spring-loaded X-Y alignment

Optical tube mounting block: Fits standard photo-style tripods

Mount: EQ-1, German-type equatorial

Slow-motion controls: R.A. and Dec. axes

Setting Circles: R.A. scaled in 10 minute increments, Dec. scaled in 2.5° increments

Latitude range: 10° to 70°

Tripod: Adjustable-height aluminum legs, accessory tray included

Case: Deluxe carry case for optical tube included, padded case for EQ-1 mount optional

Motor drives: Optional

Weight: 15.8 lbs (tube 3.7 lbs, mount 12.1 lbs)

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Orion 90 EQ instruction manual Specifications, Cleaning the Tube, Cleaning Lenses