Polar Axis Finder Scope | Orion 100 EQ specs

Azimuth fine adjustment knobs

Date circle

Ring with engraved time meridian indicator mark

	Polar scope
	alignment
Tripod	thumbscrew (3)

attachment knob

R.A. setting circle lock thumbscrew

Pointer R.A. setting circle

Meridian offset scale

Polar scope housing

Polar axis finder scope

Figure 8. For polar alignment, position the tripod so that the “N” label at the base of the mount faces north. The two azimuth fine adjustment knobs above it are used to make small adjustments to the mount’s azimuth position.

4.Move the tripod so the telescope tube (and R.A. axis) points roughly at Polaris. If you cannot see Polaris directly from your observing site, consult a compass and rotate the tripod so the telescope points north. There is a label bear- ing a large “N” at the base of the equatorial mount (Figure 8). It should be facing north.

The equatorial mount is now approximately polar-aligned for casual observing. More precise polar alignment is required for astrophotography and for use of the manual setting circles.

From this point on in your observing session, you should not make any further adjustments to the latitude of the mount, nor should you move the tripod. Doing so will undo the polar align- ment. The telescope should be moved only about its R.A. and Dec. axes.

The Polar Axis Finder Scope

A feature of the AstroView 100 EQ is the polar axis finder scope housed inside the R.A. axis of the equatorial mount (see Figure 9). When properly aligned and used, it makes accurate polar alignment quick and easy to do. Alignment of the polar finder need only be done once, unless it gets bumped or otherwise shifts its position.

Remove the cover cap from the front opening in the R.A. axis of the mount (see Figure 6). Look through the polar finder at a distant object. Focus the polar finder so that the images and reticle are sharp by rotating the eyepiece end of the finder. Notice that the reticle pattern consists of a crosshair with a cir- cle around the middle. On the circumference of this circle is a tiny circle; this is where Polaris will be placed for accurate polar alignment once the finder is properly aligned. Alignment of the polar finder is best done during the day, before going out into the field at night.

Aligning the Polar Axis Finder Scope

Aligning the polar axis finder scope so that it will accurately point at the true north pole is a two-step procedure. First, the polar finder must be rotated in its housing so that the small cir-

Figure 9. The polar axis finder scope installed in the right ascension (R.A.) axis of the mount.

cle in which Polaris will be placed in is in the proper initial position. Next, the polar axis finder must be adjusted so that it points directly along the mount’s R.A. axis.

We will start by aligning the polar finder rotationally. Refer to Figure 9.

1.Loosen the large thumbscrew just above the R.A. setting circle. Rotate the R.A. setting circle until the line above the “0” on the setting circle lines up with the pointed indicator that is cast into the mount (located directly below the large thumbscrew; see Figure 8). Retighten the thumbscrew.

2.Rotate the date circle until the “0” line on the meridian off- set scale lines up with the time meridian indicator mark. The meridian offset scale is printed on the inner circumfer- ence of the date circle, and is labeled “E20” to “W20”. The time meridian indicator mark is an engraved line on the exterior of the polar finder’s housing. It is on the “ring” of the housing that is closest to the date circle.

3.The R.A. setting circle is labeled in hours, from “0” to “23” (military time). For Northern Hemisphere observers, refer to the top numbers on the setting circle. Each small line represents 10 minutes of R.A. The date circle is labeled from “1” to “12”, with each number representing a month of the year (“1” is January, “2” is February, etc.). Each small line represents a two-day increment.

4.Loosen the R.A. lock lever and rotate the mount about the R.A. axis until the March 1 indicating mark (the long line between the “2” and the “3”) on the date circle lines up with the 4 PM mark (the long line above the “16”) on the R.A. setting circle.You may find it convenient to remove both the counterweights and the telescope optical tube to do this.

5.Now, loosen the three thumbscrews on the polar finder housing and rotate the polar finder so the small circle where Polaris will be centered is located straight down from the intersection of the crosshairs. Retighten the thumbscrews.

The polar axis finder scope is now properly set in its initial position. Next, you must align it so that it is exactly parallel to the mount’s R.A. axis:

100 EQ specifications

The Orion 100 EQ is a high-performance telescope designed for both novice and experienced astronomers. Combining precision engineering with user-friendly features, this telescope offers an exceptional observing experience.

One of the standout features of the Orion 100 EQ is its 100mm diameter aperture, which allows for ample light gathering capabilities. This feature is essential for observing faint celestial objects, making it ideal for viewing planets, star clusters, and nebulae. The optics are made from high-quality glass and are fully coated to enhance light transmission and image clarity.

The computer-controlled equatorial mount of the Orion 100 EQ is another significant advancement in its design. This mount utilizes a durable, smooth operation mechanism that allows for easy tracking of celestial objects as they move across the night sky. The built-in dual axis slow motion controls provide astronomers with the ability to make fine adjustments to their viewing angle, ensuring that the object of interest remains centered in the eyepiece.

Another key technology included in the Orion 100 EQ is its robust and portable design. Weighing in at just under 25 pounds, the telescope is lightweight enough to transport easily but offers the stability necessary for steady views during observation. The adjustable aluminum tripod further enhances the telescope's stability while providing a sturdy platform for observers.

For beginners, the Orion 100 EQ is user-friendly and easy to set up. The telescope comes with a detailed instruction manual that guides users through the assembly process. Moreover, Orion includes a selection of eyepieces and a finderscope to assist users in locating celestial objects quickly. A 25mm Plössl eyepiece and a 10mm Plössl eyepiece come standard, allowing for a range of magnifications suitable for various observing conditions.

In terms of characteristics, the Orion 100 EQ stands out with its solid build quality and intuitive design. Its sleek black finish not only adds to its aesthetic appeal but also ensures both durability and resistance to weather conditions. The telescope's user-friendly nature, combined with its impressive optical performance, makes it a perfect choice for astronomy enthusiasts.

Overall, the Orion 100 EQ is a versatile telescope that caters to a wide audience. Whether you are a novice taking your first steps into astronomy or an experienced observer seeking a reliable tool for deep-sky exploration, the Orion 100 EQ promises to deliver an outstanding visual experience and a deeper connection with the cosmos. With its thoughtfully designed features and technologies, it is indeed a worthwhile investment for anyone passionate about stargazing.