dark central spot is in fact the shadow of the secondary mirror. Turn the focus knob until the ring of light fills about 10% of the eyepiece field-diameter. If the dark central spot is offset in (i.e., not concentric with) the ring of light, your telescope’s optical system is misaligned and requires collimation.

Follow these steps for collimation of the optical system:

1.The only adjustments possible, or necessary, on the LT Series are from the three inner most screws

Collimation Screws

Figure 14: The LT Series Collimation

located at the inner surface of the secondary mirror housing.

CAUTION: Do not force the three collimation screws past their normal travel and do not loosen them more than two full turns in a counterclockwise direction or the secondary mirror may come loose from its support. You will find that the adjustments are very sensitive, usually requiring only one-half turn or less to produce the desired result.

2.While looking at the defocused star image, notice which direction the darker shadow is offset in the ring of light or notice which part of the ring is the thinnest (Pg. 41 Fig. 13, 1). Place your index finger in front of the telescope so that it touches one of the collimation set screws. You will see the shadow of your finger in the ring of light. Move your finger around the edge of the black plastic secondary mirror support until you see the shadow of the finger crossing the thinnest part of the ring of light. At this point, look at the front of the telescope where your finger is aiming. It will either be pointing directly at a set screw, or it will be between two set screws aiming at the set screw on the far side of the black plastic secondary mirror support. This is the set screw that you will adjust.

3.Using the Arrow keys at the slowest slew speed, move the defocused image to the edge of the eyepiece field of view (Pg. 41, Fig. 13 , 2), in the same direction as the darker shadow is offset in the ring of light.

4.Turn the set screw that you found with the pointing exercise while looking in the eyepiece. You will notice that the star image will move across the field. If while turning the defocused star image flies out of the eyepiece field, then you are turning the screw the wrong way. Turn the opposite direction and bring the image back to the center of the field.

5.If the screw you are turning becomes very loose, tighten the other two screws by even amounts. If the screw you are turning gets too tight, un-thread the other two by even amounts.

6.When you bring the image to center (Pg. 41, fig. 13, 3), carefully examine the evenness of the ring of light (concentricity). If you find that the dark center is still off in the same direction, continue to make the adjustment in the original turning direction. If it is now off in the opposite direction, you have turned too far and you need to turn in the opposite direction. Always double check the image in the center of the field of the eyepiece.

7.You may find after your initial adjustment that the dark center is off in a new direction (e.g., instead of being off side-to-side it is now off in an up-and- down direction). In this case repeat steps 2 through 6 to find the new adjustment screw.

8.Now try a higher power eyepiece (e.g., 9mm or less) and repeat the above tests. Any lack of collimation at this point will require only very slight adjustments of the three set screws. You now have good collimation of the optics.

9.As a final check on alignment, examine the star image in focus with the higher power eyepiece as suggested above, under good viewing conditions. The star point should appear as a small central dot (commonly referred to as an “Airy disc”) with a diffraction ring surrounding it. To give a final precision collimation, make extremely slight adjustments of the three set screws, if necessary, to center the Airy disc in the diffraction ring. You now have the best alignment of the optics possible with this telescope.

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Meade LT SC Series, LT ACF Series instruction manual Collimation Screws, LT Series Collimation
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LT Series, LT ACF Series, LT SC Series specifications

The Meade LT SC Series, LT ACF Series, and LT Series telescopes are designed to meet the diverse needs of amateur astronomers and astrophotographers alike. Each of these series caters to various levels of experience while incorporating advanced features and technologies that enhance observational stability and image quality.

The Meade LT SC Series, featuring the advanced Schmidt-Cassegrain design, excels in versatility. This series includes different aperture sizes, allowing users to view celestial objects ranging from the moon to distant galaxies. The telescopes come equipped with an AudioStar hand controller that provides a database of over 30,000 celestial objects, enabling users to easily locate and track their subjects. The built-in GPS feature facilitates effortless alignment by automatically determining the user’s location and time.

In contrast, the LT ACF Series showcases Meade's innovative Advanced Coma-Free (ACF) optics. This design minimizes coma and field curvature, providing sharp, crisp images across a wider field of view. Ideal for astrophotography, this series is enhanced by features like a fast focal ratio for better imaging of dim objects and a robust construction that ensures stability during use. The LT ACF telescopes also support advanced imaging techniques, allowing users to capture stunning images of deep-sky objects while minimizing aberrations.

The classic LT Series remains a favorite among beginners. Known for its straightforward setup and usability, this series is designed with a lightweight and portable frame. The LT Series telescope is equipped with an altazimuth mount, making it user-friendly for quick observations. The simplicity allows new astronomers to start observing with minimal technical knowledge. Additionally, these telescopes support a variety of accessories such as smartphone adapters, making it easy for users to capture their observations.

All three series incorporate Meade's proprietary StarLock technology in certain models, which facilitates automated tracking. This feature frees astronomers from the complexities of manual tracking, allowing them to focus more on the experience of observing celestial wonders.

In summary, the Meade LT SC Series, LT ACF Series, and LT Series deliver exceptional optical performance and user-friendly features, making them suitable for a wide range of astronomy enthusiasts. Whether you are a seasoned astrophotographer or a novice sky-watcher, Meade's telescopes provide the technology and capabilities needed to explore the universe.
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