Selecting an Eyepiece, Install and Using Barlow Lens

Altitude locking knob #12

Altitude adjustment rod #7

Azimuth locking knob #13

Figure 12. Altitude and azimuth moving

2.1.2.Selecting an Eyepiece

Always begin viewing with the lowest power eyepiece. (Note: a 20 mm focal length eyepiece has a lower power than a 12.5 mm one.)

The power or magnification offered by a telescope is determined by two factors: the optical or focal length of the telescope's lens and the eyepiece's focal length. This telescope's focal length is 700 mm. To calculate the magnification factor, divide the lens' focal length by that of the eyepiece. The resulting value represents the magnification factor offered by the telescope when it is used with this eyepiece. For example, using a 20

mmeyepiece provides a magnification factor of: Magnification = 700 mm/20 mm = 35X

Some words of caution on magnification. Although the theoretical power or magnification of a telescope is virtually limitless, there are practical limits, such as he earth's atmosphere. Every telescope has a useful magnification limit of about 2X per millimeter of aperture. This comes to 140X for a 70mm telescope. Moderate magnifications are what give the best views. It is better to view a small, but bright and detailed image than a dim, unclear, oversized image.

2.1.3.Install and Using Barlow Lens

A Barlow lens is used to increase the magnification of each eyepiece. Foe example, the total magnification will be 105X when a 20mm eyepiece (35X) and a 3X Barlow lens are used together. To use the Barlow lens, remove the diagonal and insert the Barlow directly into the focuser drawtube. You then insert an eyepiece into the Barlow lens for viewing. You can also insert the diagonal into the Barlow lens and then use an eyepiece in the diagonal but you may not be able to reach focus with all eyepieces.

Barlow lens

Figure 13. Using Barlow lens

2.1.4.Installing & Using the 1.5x Erecting Eyepiece

The iExplore 70AZ comes with a 1.5x erecting eyepiece, primarily for daytime terrestrial viewing. This eyepiece produces an image in the eyepiece that is correctly oriented both vertically and horizontally.

70AZ specifications

The iOptron 70AZ is a versatile and user-friendly telescope designed for amateur astronomers and families alike. Boasting a robust 70mm aperture, this telescope strikes an excellent balance between portability and performance, making it an ideal choice for both beginners and those with some experience in stargazing.

One of the main features of the iOptron 70AZ is its impressive optics, equipped with fully coated glass lenses. This enhancement reduces light loss and ensures that users get bright, clear images of celestial objects. The telescope's focal ratio of f/10 provides an ideal balance for observing both the planets and a range of deep-sky objects, granting users the flexibility to explore various astronomical phenomena.

The adjustable altazimuth mount is a significant highlight of the iOptron 70AZ. It allows for smooth and easy tracking of celestial objects as they move across the night sky, making it simple for users to locate and follow objects without hassle. The mount is also lightweight yet sturdy, providing a stable platform for observations while ensuring ease of transport.

Another attractive characteristic of the iOptron 70AZ is its uncomplicated setup process, which can be completed in minutes. This is particularly beneficial for families looking to introduce children to astronomy or beginners who may feel overwhelmed by more complex models. Combined with a user-friendly design, the telescope comes with an adjustable tripod that makes it straightforward to achieve the perfect viewing height.

Additionally, the iOptron 70AZ includes two eyepieces, a 20mm for low magnification views and a 4mm for higher magnification. This allows for a wide range of viewing options, from expansive star fields to detailed observations of the Moon and planets. Furthermore, the telescope is equipped with a red dot finder, which simplifies star locating by providing a point of reference against the night sky.

The compact and portable design of the iOptron 70AZ allows users to easily take it on trips or to darker locations away from city lights, enhancing the stargazing experience. With its combination of optics, mount stability, ease of use, and transportability, the iOptron 70AZ stands as an excellent choice for anyone eager to explore the wonders of the universe.