Astronomy can be a lot of fun if you have the right equipment and enough knowledge to know what you are looking at. Last month I reviewed the Celestron SkyScout. The SkyScout is great for learning about the stars, but it is not a telescope so you still cannot see the stars up close. This time I am reviewing the Celestron NexStar 4 SE. The NexStar line of telescopes will not only help you see the stars with more clarity and magnification, but they will also show you where they are. The only thing the NexStar is missing is a database of interesting information about each object.
- 4″ Maksutov-Cassegrain telescope
- StarPointer finderscope to help with alignment and accurately locating objects
- Internal flip mirror for convenient viewing straight through (with optional diagonal) or at 90 degrees
- Sturdy computerized altazimuth mount
- Nearly 40,000 object database with 200 user-definable objects and expanded information on over 200 objects
The biggest feature of the NexStar is probably the computerized mount. The mount allows the telescope to automatically point itself at any visible object with the push of a button. In order to get this working correctly you will need to set it up.
There are five different ways to setup the NexStar. Sky Align, which requires you to know your longitude and latitude and then use any 3 bright celestial objects to accurately align the telescope with the sky; you do not need to know anything about the objects you point the telescope at. Auto Two-Star Align also requires your location information, but it only needs you to point at one known star. This means the telescope will show you a list of stars and you need to select one and point the telescope at it. Once you have selected the first star the telescope will automatically select a second star and it will move to that star. You will then be asked to do some fine tuning to the alignment. One-Star Align is exactly like Two-Star Align, except you only have to choose the first star. Solar System Align is like One-Star align except you use the planets, moon or sun to align the telescope. EQ (equatorial) North and EQ South Alignments assist the user in aligning the telescope with polar alignment, using the tripod’s built-in equatorial wedge. The EQ alignments give you the choice of performing an Auto Align, Two-Star alignment, One-Star alignment, or Solar System alignment.
The hand controller is used for accessing all of the telescopes features. The focus is one of the few things that is not handled by the hand control. With the hand control you can select the planets, stars and other objects you want to see, change the speed that the telescope moves, and many other things.
The NexStar 4 SE has the ability to mount an SLR camera. This lets you take pictures of your favorite objects to show others. To use this mount you will need to purchase the T-Adapter for your telescope and a T-Ring that matches your SLR camera’s lens opening. There is an included cable that can plug into the telescope and camera and take the pictures for you. If you use the cable and the camera wizard the telescope will automatically move to any object and take its picture.
The telescope can also be controlled by a computer. Using the provided 6 foot RS-232 (serial) cable you can plug it into a computer and design your own tours and move the telescope.
The NexStar 4 SE comes with several pieces of software that help to make the viewing experience better. NexRemote is used to control the telescope with a computer. The Sky Level 1 Planetarium software is for exploring the Universe on your PC and printing out custom star charts of the sky. This software is really nice because it will tell you what is visible in your sky and when it will be in the best position.
As far as the telescope goes it is fairly simple. The NexStar 4 SE is a 4″ Maksutov-Cassegrain telescope and is the smallest of the NexStar line. On the telescope there is a Star Pointer Finderscope, Eyepiece, Threaded Photographic Adapter, Flip Mirror Control, and a Focuser Knob. Everything is self explanatory, but I wanted to point out that the Flip Mirror Control is used to direct the images from the top eyepiece to the bottom photographic adapter. This means you cannot use both at the same time. When you are taking pictures you will have to look at and focus the images through your camera. Most of the functionality is in the mount.
The mount uses a corded hand control for its interface. You have about 3 feet of cord that you can stretch out, so you can control the telescope while standing behind it. The hand control is really big; I would have preferred something more like the size of a small TV remote control. If the NexStar had a wireless hand control then it would be much more useful. The hand control has an LCD screen at the top and 19 buttons. The LCD screen is small and only able to display 2 lines of text at a time. The 19 buttons are used to input the names of object, control the movement of the telescope and navigate through the menus. Everything is backlit and very easy to see and use in the dark. The backlight is red which is easier on the eyes than white.
The mount also has the ability to tilt which provides for an equatorial alignment. The NexStar has two equatorial alignment modes (one for the northern hemisphere and one for the southern) that will help you to polar align your telescope when using an optional equatorial wedge. Both alignment methods require you to know the name and location of at least one star; so if you don’t, then you should skip this. Astronomy amateurs probably do not have to worry about this too much, but as you get more proficient you will want to use it because it gives the telescope better tracking ability which is very important when taking pictures.
Normally the NexStar runs off 8 AA batteries. You can buy a power adapter so you can plug it in your wall. I highly recommend this because you may end up going through a lot of batteries. Moving the mount around a lot will cause the batteries to drain faster. The longer you keep the mount still, the longer the batteries will last.
When you first get the telescope there will be a little assembly required. Basically you just need to put the mount/telescope on the tripod, then put the finder scope and eyepiece on the telescope. The tripod also has a tool tray that can be used to store extra items. I chose not to use it because when it is attached you cannot close the legs of the tripod. I needed to close the legs because I kept the telescope inside and only took it out when I wanted to use it, and found it would not fit through my door with the legs out. One other thing you need to install is the small level that is provided. I recommend that you put it on top of the battery lid so that it is always visible. This may seem like a small thing, but it is very important for the alignment that the telescope is as level as possible.
The next thing you need to do is align the finder scope and telescope. The easiest way to align the finder scope is to point the telescope at the moon or another easily findable object, and then adjust the finderscope so the red dot is in the center of that object. Once you have set up the finder scope you should never have to realign it. On the other hand you will need to align the telescope every time you turn it off and on again. The alignment method that I used the most is Sky Align. I used Sky Align because it gives the most accurate alignment. This alignment method requires you to know your longitude and latitude, and then point the telescope at any 3 bright celestial objects. The NexStar does have a GPS add-on that can take care of finding the Longitude and Latitude. Celestron was nice enough to send me the GPS add-on which makes this process easier. I was initially hoping that the GPS add-on would have made it as easy to use as the SkyScout, but even with the GPS add-on you still need to manually pick three stars and move the telescope to them.
I tried the alignment both with and without the the GPS add-on. The only difference is that the GPS will attempt to download your location information automatically. I did not have a lot of success with the alignment. After picking the three stars I mostly got a failure message and would have to do everything again. Even with the GPS module I did not have the best success. After a bit of playing around I found that the GPS had set the telescope to standard time. When I switched to daylight time I started having more success aligning. Although, even with a successful alignment I found that the telescope got out of alignment really easily. The first object I always looked at was right on, but every other object was off. Even if I went back to the first object it would never find it again. If you bump the telescope or move it with your hand it makes the problem even worse. Also, if you don’t know the names of stars, forget about any of the other alignment methods. I tried to setup the telescope to use EQ alignment because it is suppose to be better for photographing the stars, but when I went to choose a star to sync to I realized that planets are not listed and I don’t know the names of any stars. All the alignment methods except Sky Align and Solar System require you to know the location and names of stars. I usually ended up just skipping the alignment and picking out the stars on my own. Celestron really needs to make alignment of the telescope as easy as the SkyScout. With the SkyScout all you need to do is turn it on and let it sync to the GPS. There is no star alignment because it just works, and it works really well.
Once the telescope is aligned, if it works, viewing stars and other objects is very easy. You can either control the telescope manually by using the arrows on the hand control, or pick an object on the hand control and have the telescope go there automatically. The particular telescope that I got from Celestron is the NexStar 4 SE, which is one of their smallest. Because of this I could not see a lot of detail about each of the planets and stars I viewed. In fact, every planet that I saw just looked like a white circle. The reason I could not see any colors is because the telescope was not able to capture enough light to show colors. If you really want that experience you need to buy a bigger telescope. One way to kind of cheat this is to take pictures of the objects. Using long exposure photography you can get the camera to collect a lot of light which can help to get colors to show up. Also, Celestron offers a CCD camera attachment that can hook up to your computer and take pictures for you. This is probably the preferred method because it will take multiple pictures and combine them into one image, which can provide for great images of the stars.
Even though the telescope is small I was still able to see things like the rings of Saturn, they looked like one big ring, and some of the moons of Jupiter. Our own moon was brilliant and filled the entire area of the telescope. It was a very thrilling experience to see those things and I really enjoyed teaching my kids about each of the planets as we saw them, but it quickly became boring to not see anything new. If you are really serious about astronomy then I recommend that you spend a bit more money and get a bigger telescope. That way you can see more detail on each planet, and you can see the changes they go through.
I wanted to get some pictures of the planets to show you how well they looked in the telescope, but I had several problems when hooking up a camera. First, I am not a professional photographer so all the pictures I took were a bit fuzzy. I assume I left the shutter open too long or not long enough or maybe the tracking on the telescope was off so the image drifted while the shutter was open, there are so many reasons this could happen. I am fairly sure the telescope was in focus because I could clearly see the rings of Saturn through the cameras view finder. Second, the camera added a lot of extra weight to the back of the telescope and it became back heavy. If I bumped the telescope while adjusting the focus or something the telescope would tilt upwards because of the weight. I hope this is only because of how small the telescope is and the bigger telescopes would not have this problem. Celestron should offer a way to balance the telescope or tighten the mount so it does not move so easily. Third, the actual attachment for the camera prevented the telescope from pointing up. By the time it gets dark, this time of year, Saturn is almost straight up and with a big camera attached to the back of the telescope it cannot go very far up. In order to fix that you have to play around with the tripod and lower the back legs, which messes up the alignment. If Celestron made it possible to attach the camera to the top eyepiece then this would not be a problem. The last problem was the camera T-Ring never locked in place as well as a lens does, so if I bumped the camera it would rotate the camera on the mount and I would have to rotate it back, it’s possible it’s a flaw in the particular T-Ring I have. This didn’t hurt anything, it was just frustrating to have to keep fixing things.
I did finally get a friend to help me take pictures. He is much better then I am with a camera. We got some really good shots of the moon and we tried Saturn and Venus, but they were so small that it was very difficult to tell if they were in focus when taking the pictures. Needless to say the planets did not turn out as well as the moon. As you can see from the picture the moon was at about 3/4 and you can easily see many of the details of the moon like crater Tycho at the lower right, crater Capernicus lower left and Mare Crisium at the top, but you will notice that the moon is not very bright. We had to under expose the picture so the brightness did not overwhelm the photo.
The NexStar 4 SE uses the Maksutov-Cassegrain design, which has 3 mirrors in the tube. Because of this the image will appear right side up, but reversed left to right. You will not really notice this when you are looking at stars, but it does affect how the telescope moves. When you press the left arrow it moves the telescope to the left. As the telescope moves to the left you would expect the stars to move to the right. Instead, the stars also move to the left. It will take a little while to get used to.
The NexStar has a computer interface and will connect to your computer with a RS-232 cable. The ability to connect to a computer offers a lot of potential for more fun by letting you design tours of the sky and moving the telescope from your computer. The only problem here is that the cable provided is a RS-232 cable and I have not seen a computer with a RS-232 port for a long time, especially not a laptop. Since the cable is only about 6 feet long you are going to need to either drag your desktop outside or use a laptop. I would highly recommend that Celestron make this cable longer and change it to USB. I was unable to test this feature because none of my computers have a RS-232 port, I have 2 laptops and 3 desktops, all of them less than 5 years old.
Warranty and Support
The NexStar 4 SE comes with a 2 year warranty. Like usual, the warranty only covers manufacturer defects and not any damage that you may cause by bumping it around. Because of how delicate it is I recommend that you use great caution at all times and never let children use it without supervision. If you happen to knock a mirror out of alignment or something you will have a very expensive repair bill.
The optics on the telescope are really good. I was able to see planets really clear. The problems I had were with the software and taking pictures. Even though this is suppose to make finding stars easier, I found it to be unreliable and cumbersome. If you really need help finding the stars then I recommend you buy a manual telescope and spend the money you saved on a SkyScout. The SkyScout is much better than this telescope at finding the correct locations of each star, and it is much easier to setup for beginners. If you are a moderate or expert astronomer then you may want to look into a more powerful telescope that will provide a better picture with more color and detail. I do not recommend this telescope for astrophotography, there are just too many frustrating things that get in the way of taking good pictures. As always compare prices before purchasing.
|JusTech'n editors' rating|