Is Bigger Always Better? The Celestron CPC 1100


The star of many a star party. Credit: Celestron

Ready to move up to a big telescope? Perhaps you’ve cut your teeth on a 4-inch refractor, or a 6-inch reflector, and you’re hungering for more light-gathering ability, and would appreciate full computer control. If so, consider the Celestron CPC 1100. It has a generous 11-inch mirror and operates at f/10, for an effective focal length of 2800 mm. With this much aperture, familiar objects begin to take on new definition and character, and the dimmer targets in your star atlases are now within reach.


Pluses: Deep sky objects, planetary, lunar observing.

Who it is for: The intermediate to advanced astronomer who’s not deterred by moving a large piece of equipment around.

Who it is not for: Anyone unwilling to lug around a big, heavy telescope. Observers on a budget. Anyone who loves to observe at low power.

While at first it may sound like everyone should buy one of these telescopes, let’s talk about the literal elephant in the room. This may seem obvious, but this is a big and massive telescope. While the tripod weighs only 19 lbs (9 kg), with the older 2010 version weighing 27 lbs (12 kg), the optical tube assembly clocks in at an imposing 65 lbs (29 kg) – equivalent to the weight of a typical young pre-teen. This heavy tube must be lifted, carried and maneuvered until it mates with a pin on the top of the tripod plate, an operation that can be quite frustrating – not to mention nerve wracking – until you get a feel for it.

The CPC set atop the optional Equatorial Wedge (MSRP $419.95). Credit: Celestron

No matter how many times the author has assembled the telescope, he still gets nervous when contemplating this operation. Many users find their motivation for bringing out a large piece of equipment diminishes over time. After assembling the telescope each night, the author found himself mentally calculating the amount of time it would take to break it down, and adjusted his observing time accordingly.

The author’s tripod and CPC optical tube assembly inside optional third-party JMI hard case. Credit: Ed Ting

The built-in GPS simplifies initialization. Under the default mode, the user only need point the telescope at any three bright objects in the sky, including planets or the moon, and the computer handles the rest. The telescope’s pointing accuracy is very good, especially considering its 2800 mm focal length. Due to that long focal length, the telescope excels at smaller deep sky objects like globular clusters, as well as planetary nebulas. Under steady seeing conditions, the planets can look very impressive.

Are there any other drawbacks? The long focal length, which helps magnify smaller objects, can be a hindrance when viewing larger targets like the Andromeda Galaxy (M31), the Double Cluster in Perseus, or the Pleaides. You can get the feeling that you can never “back away” enough to see the entire object. For example, a 32 mm Tele Vue Plossl, considered a low power eyepiece in a mid-sized telescope, yields 87.5x in the CPC 1100. This close-up view can contribute to a feeling that observers sometimes characterize as “claustrophobic”.

The author’s CPC 1100 fully set up and ready for a night of observing or imaging. Credit: Ed Ting

With those caveats in mind, if you’re looking for a large-aperture computer-controlled Schmidt-Cassegrain, the Celestron CPC 1100 could be just what you’re looking for. Good viewing to you all!

MSRP:  $2999




About Ed Ting

Ed Ting is a well-known amateur astronomer. His work has appeared in Sky & Telescope, Night Sky, Skywatch, Amateur Astronomy, Discover, and Popular Mechanics magazines. His web site,, is a widely-read telescope review web site. He is a National Science Foundation Ambassador to Chile and a NASA Solar System Ambassador.

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