Orion 90 EQ Terrestrial Viewing, Photography, Care and Maintenance, Transporting, Storing

French astronomer Charles Messier, which represent some of the best and brightest deep-sky objects.

Determine in which constellation the object lies. Now, find the constellation in the sky. If you do not recognize the constella‑ tions on sight, consult a planisphere. The planisphere gives an all-sky view and shows which constellations are visible on a given night at a given time.

Now, look at your star chart and find the brightest star in the constellation that is near the object you are trying to find. Using the finder scope, point the telescope at this star and center it on the crosshairs. Next, look again at the star chart and find another suitably bright star near the bright star cur‑ rently centered in the finder. Keep in mind that the field of view of the finder scope is about 6°, so you should choose another star that is no more that 6° from the first star, if possible. Move the telescope slightly, until the telescope is centered on the new star.

Continue using stars as guideposts in this way until you are at the approximate position of the object you are trying to find (Figure 7). Look in the telescope’s eyepiece, and the object should be somewhere within the field of view. If it’s not, sweep the telescope carefully around the immediate vicinity until the object is found.

If you have trouble finding the object, start the star hop again from the brightest star near the object you wish to view. This time, be sure the stars indicated on the star chart are in fact the stars you are centering in the eyepiece.

7. Terrestrial Viewing

The StarMax 90mm not only excels at astronomical observ‑ ing, it’s great for terrestrial (land) viewing too. The equatorial mount, however, is not well suited for land viewing due to its motion about R.A. and Dec. axes instead of altitude (vertical) and azimuth (horizontal) axes. Because of this, we recom‑ mend removing the optical tube from the EQ-1 Mount and placing it on an appropriate photo-style tripod. This is easily done by rotating the thumb wheel clockwise on the mount’s 1/4"-20 adapter. Make sure to have a firm grip on the tube as it releases from the mount. Now, connect the optical tube to a photo tripod by threading the tripod’s 1/4"-20 shaft into the hole in the tube’s mounting block.

The included mirror star diagonal, while preferred for astro‑ nomical observing because of its viewing angle and better resolution, is not optimal for land viewing because it inverts images from left-to-right. We recommend purchasing an optional 45° correct-image diagonal for terrestrial observing; it provides a more comfortable viewing angle for land viewing and an image that is oriented the same as the naked eye.

For terrestrial viewing, it’s best to stick with low power eyepiec‑ es that yield a magnification under 100x. At higher powers, images rapidly lose sharpness and clarity due to “heat waves" caused by Sun-heated air.

Remember to aim well clear of the Sun, unless the front of the telescope is fitted with a professionally made solar filter and

the finder scope is covered with foil or some other completely opaque material.

8. Photography

With an optional camera adapter, the StarMax 90mm becomes

a1250mm f/13.9 telephoto lens for a single-lens reflex cam‑ era. For long-distance terrestrial or astronomical photography, you need only a T-ring for your specific camera model. The T- ring attaches to your camera and threads onto the StarMax’s eyepiece adapter (first remove eyepiece and diagonal), cou‑ pling the camera body to the telescope.

Use the camera’s viewfinder to frame the picture. Use the telescope’s focuser to focus the image.

You may want to consider using a remote shutter release instead of the shutter release on the camera. Touching the camera can vibrate the system and blur the resulting photo‑ graphic image. Also, be sure to use a solid tripod.

9. Care and Maintenance

Transporting

The included soft carry case provides an excellent way to transport the optical tube and its accessories. Remove the tube from the mount by rotating the knurled thumb wheel on the mount’s 1/4"-20 adapter. Make sure to have a firm grip on the tube as it releases from the mount. To place the optical tube in the case, the eyepiece, diagonal, finder scope and bracket must be removed from the tube. When removing the eyepiece and diagonal, remember to first loosen the securing thumb screws. The finder scope and bracket can be removed together by loosening the thumb screw on the tube’s dovetail mount. Cover the front of the optical tube with the dust cover and the rear opening of the eyepiece adapter with its cap. Now place the tube in the case’s main compartment under‑ neath the padded divider. The finder scope and bracket can be placed on top of the divider as one unit. The eyepiece and diagonal should be placed in the external compartments of the case.

It is not necessary to completely disassemble the mount to transport it. It will be convenient to remove the accessory tray (by unthreading the three wing screws) in order to fold the tripod legs together. It may also be convenient to remove the slow-motion control cables and counterweight shaft. Orion offers an optional Padded Scope Case that will fit the entire EQ-1 Mount.

Storing

If you give your telescope reasonable care, it will last a lifetime. Store it in a clean, dry, dust-free place, safe from rapid chang‑ es in temperature and humidity. Do not store the telescope outdoors, although storage in a garage or shed is OK. Small components like eyepieces, diagonals, and other accessories can be kept in the included carry case or in an optional eye‑ piece case. Keep the dust cover on the front of the telescope and cap the rear opening of the eyepiece adapter. Also keep

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