The Maksutov optical design of the NexStar 90 SLT gives the telescope a focal length of 1250mm in an optical tube only twelve inches long. This long focal length is ideal for bringing out detail on the Moon and planets. When I look at the Moon for example, the view is crisp and clear with no trace of false color. When I look at Saturn I can easily push the magnification to 200X with an optional 6mm plossl eyepiece. When I look at deep space objects I often like to use an optional 32mm plossl eyepiece (39X magnification) because objects like M45 the Pleiades cluster and M31 the Andromeda galaxy look better with a wider field of view.

The NexStar 90 SLT also features Celestron's patented SkyAlign technology. With SkyAlign I don't need a star chart or a compass to align the telescope, I just enter the date and time then point the telescope at three bright stars. SkyAlign tells me the star names, and allows the telescope to find over 4,000 stars, planets, and galaxies by just pushing a button. The accurate tracking makes it easy to get high power views of the planets, and allowed me to take some great pictures using a Celestron NexImage webcam. I also like the "Two-Star align" and "Solar System align" modes because I can often get the NexStar system up and running while older scopes are still waiting for their alignme