Celestron NexStar 4SE Review: Getting Closer

written by TTB
TTB score


The Good


The Bad

Check price on↓

Celestron NexStar 4SE is a lot of tech built onto little optics.


Is NexStar 4SE worth it? It depends. For the price tag of 500$, there are 8″ Dobsonians and phenomenal refractors. For automation, you are sacrificing optical quality at this price range. 

But it has well-built and reliable automation. The optical tube is phenomenal for planetary observations. In the end, the choice is yours.

Aluminum Secondary Mirror



102mm(4″) Aperture

1325mm Focal Length


Planetary Performer

NexStar 4SE has only one flaw preventing it from becoming one of the best planetary performers in its price range. Its secondary mirror. It is merely an aluminum spot instead of a high-quality mirror. NexStar 4SE has other problems, but this is the most important one. 

The secondary mirror is low-quality and cheap.

Celestron NexStar 4SE is a Maksutov-Cassegrain. It is a planetary performer at its core. It effortlessly gathers detail from Solar System objects such as Jupiter, Mars, Venus, and Saturn.

Planetary Performance

Jupiter shows its Galilean Moons, colorful stripes, and The Great Red Spot. 

Saturn shows its unique yellow-green color and its rings. The Cassini Division and a couple of its moons are visible on ideal conditions.

Mars shows its red color and some surface detail as black and white stains. These are the Polar Ice Caps and iron oxide on the surface.

Venus is visible as a yellowish disk. Its surface is impossible to observe with any telescope, but its phases are observable.

Neptune and Uranus appear as blueish dots. 

Mercury and Pluto are hard to observe with any telescope.

Overall planetary performance is pleasing. You can get the major details, and as I’ve mentioned before, NexStar 4SE is easy to focus at high magnifications. MAK’s are great for Solar System observations. The same is not true for deep space.

Deep Space Performance

Deep space observations aren’t mesmerizing.

Deep space performance is not that good for two reasons, the unusually high focal ratio(f/13) and low aperture(100mm). 

It is hard to fit the largest space objects inside the field-view, and even you did, very little detail is visible. You can solve this with a focal reducer such as this one, but still, deep space performance is not exciting. 

But, you can get great images of double star clusters. They are usually small in size and remarkably bright. They are like antidotes for the optical weaknesses of Celestron NexStar 4SE.

Is Astrophotography possible with Celestron NexStar 4SE?

Do not believe what is written on official marketing pages. Celestron NexStar 4SE is not suitable for serious astrophotography. 

The problem is the nature of the mount. It is an altazimuth instead of an equatorial. It moves in an up-down motion. For astrophotography, you need a curved motion to counter the Earth’s rotation. 

Built-in Wedge

Celestron tried to solve this problem by building a “wedge” inside the mount. It lifts the optical tube and creates the ability to follow space objects in a curved motion. But the wedge is not precise enough for long-exposure photography. 

The built-in wedge is not precise.

What is possible is 30-40 second images of Solar System objects. The Moon, Jupiter, Saturn, and Mars are all possible to image with Celestron NexStar 4SE. 

Galaxies and Nebulas are almost impossible to image, but double star clusters are possible. As I’ve mentioned before, they are bright, so easier to image with short exposures.



Sturdy Build

Reliable Accuracy

No Battery

2″-Steel Tripod

The Battery Problem

Celestron doesn’t send a built-in battery with NexStar 4SE, which is ridiculous in this day and age. We are surrounded by batteries that are built into smartphones, cars, and Celestron doesn’t send a battery for a small telescope. 

There is no built-in battery.

Instead, there is a battery slot for 8 AA batteries. They run out in a single night and expensive to supply as well. 

So, in the end, you have to use an external power supply. This is not only a burden, but it also may mess up the alignment if the cable is not lightweight. 

 Is NexStar Mount Reliable?

This is the reason why the mount is a confusing part. Because as compensation to the battery problem, the mount is incredibly reliable. It is well-built, sturdy, and will stand years of use. 

This is the reason why the mount is a confusing part. Because as compensation to the battery problem, the mount is incredibly reliable. It is well-built, sturdy, and will stand years of use. 

The mount is reliable and sturdy.

The motors inside are quiet and reliable. They are less prone to breaking down than most of the motorized mounts out there. This is a considerable achievement of Celestron.

In addition, the motorized nature of the mount creates a sturdy structure. The optical tube shakes much less and provides a pleasant observation experience.


The tripod is delightfully strong.

The tripod is also much better than any I’ve seen in this price range. It is a 2″-steel tripod. It is sturdy enough to carry the optical tube and the motorized mount. It also can take extra accessories such as a DSLR camera, heavy eyepieces, and finders. 

The tripod exceeds expectations.

The Software

There are three ways to control the optical tube. 

The first and obvious one is the hand controller. Although the software is 30-year-old technology, it is reliable. 

The second one is getting the Celestron WiFi Adapter and using the SkyPortal App. Although the app works pretty well, the adapter occasionally loses connection. 

The third is to use third-party software. I wouldn’t recommend this if you are not going to get into serious astrophotography.

Celestron StarSense

Celestron recently added StarSense to their upgrade line up. StarSense is a camera that auto aligns your telescope and works surprisingly well. But it is not cheap. You can get a professional DSLR Camera instead of it. 



25mm Plössl Eyepiece

Red Dot Finder

1.25″ Built-In Focuser

1.25″ Diagonal

There is not much to talk about in this section. Celestron only sends a 25mm Plössl eyepiece and a red dot finder with the telescope. You probably will spend an extra 100-150$ for extra eyepieces, finders, and correctors for NexStar 4SE.

The 25mm eyepiece is perfect for NexStar 4SE. It balance the high focal ratio with a low power eyepiece. 

The red dot finder is cheap. It is not easy to align, and with the 6″ and 8″ NexStar SE models, it is impossible. But, this is a GoTo telescope, so you won’t use the finder that often.

Recommended Accessories

Celestron Omni 40mm Plossl

SVBONY 15mm Redline

SVBONY 9mm Redline

A 40mm Plossl has no wider of a field of view than a 32mm unit in a 1.25” barrel, but with the 4SE’s long f/13 focal ratio you get a 3mm instead of a 2.5mm exit pupil, and a magnification of “only” 33x – and given that a 2.5mm exit pupil is already rather small/dim for viewing deep-sky objects, backing off the magnification a bit more certainly isn’t a bad idea. You’ll also get a wider true field of view than the included 25mm Plossl eyepiece – about 1.7 degrees. The SVBONY 15mm “redline” ocular provides 88x with the 4SE – at the low end of what you want for lunar and planetary viewing – while the 9mm provides 147x, nearly the most the little 4SE can handle. You could go up to 200x with this scope, but we think the 9mm redline is more appropriate than most other inexpensive options.


Cheap Secondary Mirror

Moderate Power

No Battery

The secondary “mirror” is merely and aluminum spot. It lowers the image quality.

The 100mm aperture is not wide enough for most deep space objects.

There is not a battery built inside the mount. The 8 AA battery slot finishes up in a single night. An external power source is necessary.


Although it has its problems, Celestron NexStar 4SE is among the decent players in terms of planetary performance and GoTo abilities. Its sturdy base and reliable motors are appealing. 

Celestron NexStar 4SE is not a bad choice for astronomers who are seeking Solar System performance and autonomy. 

TTB score


The Good


The Bad

Check price on↓