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Celestron

Celestron - NexStar 90SLT Computerized Telescope - Compact and Portable - Maksutov-Cassegrain Optical Design - SkyAlign Technology - Computerized Hand Control - 90mm Aperture

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Style: NexStar 90 SLT


Set: Telescope Only


Features

  • Computerized Star Locating Telescope: The Celestron NexStar 90SLT is a computerized telescope that offers a database of more than 40,000 stars, galaxies, nebulae, and more, the telescope locates your object with pinpoint accuracy and tracks it
  • Compact and Protale;This telescope for adults and kids to be used together is ideal for weekend camping trips or excursions to dark sky sites. Its compact form factor makes it easy to transport and assemble just about anywhere
  • Maksutov-Cassegrain Optical: The NexStar 90SLT is the smalles in the SLT family. The 90mm aperture gathers enough light to see our Solar System and beyond. View Saturns rings, Jupiters cloud bands, and the Moon in brilliant detail
  • fast Setup with SkyAlign :Celestrons proprietary SkyAlign procedure has you ready to observe in minutes. Simply center any three bright objects in the eyepiece and the NexStar SLT aligns to the night sky, ready to locate thousands of objects
  • The NexStar 90SLT Computerized Telescope includes a FREE download of one of the top consumer rated astronomy software programs for an interactive sky simulation
  • UNBEATABLE WARRANTY AND CUSTOMER SUPPORT: Buy with confidence from the worlds #1 telescope brand, based in California since 1960. Youll also receive a two-year warranty and unlimited access to technical support from our team of US-based experts.

Description

The Celestron NexStar 90SLT is a computerized telescope that offers a database of more than 40,000 stars, galaxies, nebulae, and more. The telescope locates your object with pinpoint accuracy and tracks it. At the heart of the telescope’s Maksutov-Cassegrain optical design, a 90mm primary mirror gives fully color-corrected views ideal for astronomical use. The 90SLT comes with a fully computerized NexStarPlus hand control. The computerized hand control gives you the ability to automatically slew to any of its 40,000Plus objects, including over 600 galaxies, 300 clusters, and dozens of beautiful binary stars. This telescope for adults and kids to be used together is ideal for weekend camping trips or excursions to dark sky sites. Its compact form factor makes it easy to transport and assemble just about anywhere. With its pre-assembled, adjustable steel tripod, the NexStar 90SLT can be up and ready to use in a matter of minutes. Our SkyAlign alignment technology and the included StarPointer Finderscope with a red LED make aligning a breeze. Simply center any three bright objects in the eyepiece and the NexStar SLT aligns to the night sky, ready to locate thousands of objects. The NexStar 90SLT Computerized GoTo Telescope also includes a free download of our Starry Night Special Edition astronomy software for an interactive sky simulation. This computerized telescope allows you to view the lunar surface, the rings around Saturn, the moons of Jupiter, and a number of the Messier objects, such as the globular cluster in Hercules (M13) or the Great Nebula in Orion (M42). Buy with confidence from the world’s 1 telescope brand, based in California since 1960. You’ll also receive a two-year warranty and unlimited access to technical support from our team of US-based experts. Celestron's NexStar 90 SLT is the most compact telescope in Celestron's computerized NexStar line, with excellent Maksutov-Cassegrain optics that deliver delightful views of the Moon and planets. The NexStar 90 SLT package includes everything but the batteries. With a fully illustrated quick set-up guide, no tools are needed to assemble the telescope with its steel tripod, motorized mount, and computer hand control. Two eyepieces are included, a 25mm for 50X magnification and a 9mm eyepiece for 139X. The package even includes the latest version of "The Sky X", software that turns your PC into a virtual planetarium. 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 alignment stars to appear in he twilight. I enjoy using the NexStar 90SLT because it has excellent optics in a compact, twelve pound package that I can carry outside in one trip and be ready to go in minutes. A computerized telescope may take practice to set up; if I don't enter the time correctly the alignment may fail for example. The other drawback of a computerized telescope, of course, is the short life of standard AA batteries. A rechargeable 12-Volt battery is a handy way to power the NexStar 90SLT, and I like to keep the tripod legs short and observe while seated because this gives me a solid and comfortable view. --Jeff PhillipsPros:Excellent optics Compact and portable Easy computerized go-to tracking "The Sky X" planetarium software included Cons:Short battery life with AA batteries Suggested Options: Celestron Accessory Kit Celestron PowerTank battery Quarter Moon shot at 50X with a Powershot camera Quarter Moon closeup shot at 200X with Neximage camera Crater Ptolemaeus shot at 400x with Neximage and 2x barlow Planet Mars shot at 400x with Neximage and 2x barlow Planet Saturn shot at 400x with Neximage and 2x barlow

Brand: Celestron


Model Name: NexStar 90SLT


Optical Tube Length: 21 Inches


Eye Piece Lens Description: Plossl


Objective Lens Diameter: 9E+1 Millimeters


Telescope Mount Description: Altazimuth Mount


Product Dimensions: 16"D x 32"W x 54"H


Focus Type: Manual Focus


Power Source: Battery Powered


Finderscope: Reflex


UPC: 050234220873


Global Trade Identification Number: 73


Manufacturer: Celestron


Brand Name: Celestron


Model Name: NexStar 90SLT


Number of Batteries: 8 AA batteries required.


Coating: Fully Coated


Focal Length Description: 1250 millimeters


Field Of View: 1.7 Degrees


Zoom Ratio: 50


Power Source: Battery Powered


Finderscope: Reflex


Eye Piece Lens Description: Plossl


Mount: Altazimuth Mount


Focus Type: Manual Focus


Item Weight: 6.9 Kilograms


Exit Pupil Diameter: 4.09 Millimeters


Objective Lens Diameter: 9E+1 Millimeters


Item Dimensions D x W x H: 16"D x 32"W x 54"H


Optical-Tube Length: 21 Inches


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If you place your order now, the estimated arrival date for this product is: Tuesday, Dec 24

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Top Amazon Reviews

    • Great optics. Here's what to do if you get the "BOOT LOADER Invalid Pkg: 0080" error.
Style: Nexstar 130SLT Set: Telescope Only
OK, here is the Bible according to Celestron SLT scopes. When the scope is working, it's fantastic (see below if you have a non-working scope with a boot loader failure). The Newtonian design is comfortable to look through - the eyepiece is at the front of the scope, and it is positioned around eye-level when standing. Newtonian optics are also simple, which keeps the cost down (and minimizes light lost to lens absorption). The optic properties of this scope are outstanding. The 650mm focal length and 150mm (about 5-1/8") aperture are great specs, especially when paired with the highly-recommended Celestron accessory kit (Celestron Model 94303, available on Amazon). The scope comes with a 9mm and 25mm eyepiece, for magnifications of 72 and 26 power (magnification is focal length divided by eyepiece length, so magnification increases as focal length increases, and decreases as eyepiece length increases). The big 130mm aperture of this scope gives the scope a maximum useful magnification of about 307 power, using the rule of thumb that you can magnify 60 times for each inch of aperture. At a focal ratio of f5, this is a fairly "fast" scope, meaning it lets in a lot of light for it's focal length. The f-number is the focal length divided by the aperture size, and the lower the f-number, the faster the scope. Faster is (generally) better. F-numbers will be familiar to photographers, and telescopic "lenses" operate on the exact same concept as fast photographic lenses. In photography, a lens is "fast" because it allows a shorter shutter speed (because it lets in more light), meaning you can capture faster motion that would be blurry with a longer exposure (as would be required by a "slower" lens). The auto-orientation works like magic, but it's better to give it very precise time and location. Use a GPS for location; don't just tell it what city you are in (you can choose your location input method). For some reason, the controller can remember your last location and the time zone of your previous observation, but the controller does not keep time when it is switched off, so you must enter the (exact) time again whenever you switch the power off and back on (C'mon, Celestron - seriously?) You can orient the scope by pointing the scope at ANY three bright objects (you do not need to know what they are) or two objects if you know what they are (but this is said to be less precise). The scope must be level (it has a built-in level bubble). Although this scope is not really classified as a "beginner's scope," it is great for beginners - you don't need to know anything to begin viewing amazing things, and a beginner will not "outgrow" this scope anytime soon. The only comparable computerized Newtonian scope that I could find in this price range is the Orion StarBlast 6i IntelliScope, but it is available only with a table-top mount (???). If that Orion scope (750mm focal length, 6-inch aperture) was available with a sturdy tripod mount in this price range then I would be writing this review for that scope, because I would have bought that scope instead, without a doubt. Orion lost my business because they expected me to have a study TABLE available at each observation site. The optional Celestron accessory kit includes (among other things) 6mm, 8mm, 13mm, 17mm, and 32mm eyepieces and a Barlow 2X adapter. With a 6mm eyepiece and a Barlow 2X adapter (which effectively doubles the magnification of the eyepiece, making it a 3mm focal length), the scope can achieve a magnification of 216 power (pretty respectable). You could purchase shorter eyepieces or a 3X Barlow to push the magnification near the 307 power limit, but I don't think you will find yourself wanting to do so - you will be amazed at what you can clearly see (the bands of Jupiter and its Galilean moons, the rings of Saturn, etc). Note that the 307-power limit cannot be exceeded with eyepieces or Barlow lenses - the image will be pretty much worthless if you try to exceed this limit, which is a function of how much light the scope can gather (which is determined by the aperture size). As you approach this limit, the image quality decreases, so you will probably find images much more satisfying at low-to-mid-200 power than you would at theoretical maximum 300+ power. The gray moon filter in the accessory kit is especially useful for bright objects (such as the moon, of course, but also Venus and Jupiter). The longer eyepieces are needed for viewing large objects such as various asterisms, galaxies, and nebula. Some of these objects span 2 or 3 degrees of sky (or more) - which is really big (the sun and moon are 0.5 degrees.) Some objects can only be fully viewed at very low magnification (such as afforded by binoculars), so don't make the mistake of assuming that high magnification is always better. If you attend a star party, expect to find binoculars (usually mounted on a tripod) in use. The Pleiades star cluster, for example, is best observed at lower magnification. The eyepieces that come with the scope (and the accessory kit) are 1.25" diameter, but the scope can also accept large, very nice (and expensive) 2" eyepieces - just remove the 1.25" adapter which comes with the scope. The tripod mount is good, but will wiggle a bit in the breeze, especially at higher magnifications. It helps to add some weight - the tripod has a small shelf which lends itself to this purpose. A couple bags of rice or beans will do, but I bought a 20-lb theatrical-grade sandbag (double zippers keep sand out of my optics, and sand doesn't attract bugs or rodents). Put that weight on your tripod and don't touch the scope while viewing (take your hand OFF of the focus knob) and you should have a steady view, even in breezy conditions. Stiff winds may require additional measures, such as springs attached to the legs and anchored to stakes in the ground. I was told by someone at a Star Party that this mount is not well suited for long-exposure deep-field photography. As it tracks objects across the sky, the mount makes slow adjustments, but it does not adjust azimuth (side-to-side) and altitude (up-and-down) at the same time, but in succession, in a stair-step pattern. The eye won't notice, but a long-exposure photo will see blurring. Alas. But I have not verified this info. In any event, it should work fine for short-exposure shots, like the moon (you will need a camera adapter, of course). The motorized mount goes through batteries pretty fast, especially if it is tracking something all the time. The default power source of eight (standard alkaline) AA batteries will probably last a night, but I would not push it to two nights if I had been tracking the whole night before. You can hook it up to a car battery and it will run forever. I use a wheelchair gel battery - they are smaller and lighter than car batteries, and will take the deep-cycle use (charge and deplete, charge and deplete). Buy a trickle charger and use it when the battery is not being used, to keep the battery fresh and extend its life. Or you can get the Celestron Power Tank. You can use an AC adapter if you have access to AC - any adapter that puts out 12 volts DC at 2.5 amps or more with a 2.5mm barrel plug (negative on outside, which is standard) will work just fine (you can have all the extra amps you want - it won't hurt anything). There are scads of suitable adapters on Amazon that are a whole lot cheaper than the one Celestron sells. This is a Newtonian scope, and Netownians are subject to collimation errors, meaning that the two mirrors are not precisely aligned. I recommend the Celestron Collimation Eyepiece (Celestron Model 94182, available on Amazon). This will allow you to quickly and easily (and accurately) calibrate your scope for an absolutely perfect image. Some people do this each time they transport their scope, because any sort of vibration can cause the mirrors to drift (though it seems to be a rather minor problem for this scope, in my experience). The instructions that come with the eyepiece are excellent. Get a red flashlight. Celestron makes one that has a dimmer. Red won't mess up your night vision nearly as badly as other wavelengths. I rate this scope at five stars, despite the BOOT LOADER problem (solution below). ========= BOOT LOADER PROBLEM ==================================================== Within two days of getting this scope, it failed to "boot" (the mount is computerized, and it needs to successfully "boot up," just like any computer. If it cannot boot, it is useless). When the hand controller was turned on, it said, "reading packages" and then stopped with an error message, "BOOT LOADER Invalid Pkg: 0080." This renders the scope dead - it cannot be moved, even with manual arrow buttons. Fixing the problem is a bit tricky. You need to flash the firmware in your hand controller (which has somehow become corrupted), but it's not as simple (or as well-documented) as it should be. First, you need to buy a serial cable to connect your computer to the controller. It's 9-pin RS-232 (female) on one end and a modular connector on the other end (it looks like a telephone plug). The Celestron model number for this cable is 93920, and you can buy it on Amazon. If you have a reasonably modern computer then you probably don't have a serial port. If you have a 9-pin MALE D-connector then you have a serial port (though it may be disabled in your system BIOS settings). Otherwise you need to buy serial capability - I recommend a USB to Serial converter (also available on Amazon from many suppliers). Connect the computer to the controller. Make sure you are plugging the serial cable into the base of the handheld controller, and not into the body of the motorized mount. Both the controller and the mount have modular serial connections (and both can be flashed), but you are flashing the handheld controller, not the mount. You need to download and install the Celestron Firmware Manager (CFM) from Celestron's website (it's in Support/Downloads/Software, near the bottom of the list). It's a Java application, so it should work on any computer platform. But it will be downloaded as a zipfile - you must extract the contents and then run CFM.jar (on Windows, just double-click it). You can't run it within the zipfile - it must be extracted. Make sure your scope is connected first. THIS IS IMPORTANT: There are two types of Celestron motorized controllers. There's the Alt/Az (which is used by this SLT mount, as well as LCM, SE 4/5/6/8, and CPC) and the Equatorial mount (used by CGE, Advanced, and CGE*). In the CFM menu (along the top of the CFM window), select "Hand Control" and make sure the proper type of control is selected for your model of scope (this CST scope is Alt/Az). THIS IS THE REALLY REALLY IMPORTANT PART - Under the mount type selection you will see three radio buttons. The first one is selected by default, and it tells CFM to automatically detect the mount type. This is NOT GOOD. CFM thought I had an Equatorial mount. Even if I select Alt/Az, my selection will be overridden by the "Auto Detect" option. Select the Second option, which says "Always do what I selected this time" and CFM will then respect your selection. Now flash the controller in the CFM, and you should be good to go. And if you go to a remote site or star party, it's a good idea to bring a laptop with CFM (and your cables), just in case you need to do this again. I was 160 miles from home (beneath a rare Class-1 darksky!!!) when I had this problem. Fortunately it was only an hour before sunrise, so I didn't miss too much. ... show more
Reviewed in the United States on September 21, 2012 by David Filmer
    • Great scope once you get the setup down
Style: Nexstar 130SLT Set: Telescope Only
Review Image by Robert Johnson Robert Johnson
Review Image by Robert Johnson Robert Johnson
Review Image by Robert Johnson Robert Johnson
Review Image by Robert Johnson Robert Johnson
My wife bought this scope for me for Christmas. I had no experience with astronomy prior to that. It's a little finicky to set up but once you do it correctly, it'll work well. The image may not be exactly in the center but it should be close. The eyepieces that come with it are just okay. They're a step below kelner eyepieces (which is below Plossls). For eyepieces, use a low power eyepiece (25mm) to scan for objects. With eyepieces, the lower the number the higher the magnification. If you buy eyepieces, stick to good quality eyepieces in the 5mm to 35mm range. More magnification (<5mm) doesn't really help as the scope is limited by the atmosphere. Lower magnification eyepiece (>35mm) will result in an exit pupil that is too large (makes it difficult to see without a moving black blob appearing in the eyepiece). Celestron X-Cel eyepieces would work well for this scope and aren't too expensive. I like the Baader Hyperion as well. It gives a wide angle view and a large eyeglass with good eye relief to look through (great for eyeglass wearers). A x2 Barlow lens is a good option to pick up as well. Combined with your eyepieces, it doubles your available magnifications (9mm becomes a 4.5mm, 25mm becomes a 12.5mm). I have the Orion shorty x2 barlow. Don't bother with the eyepiece kits. The optics are too close together in strength so you'll probably only use 3 of the 5. The color filters are pretty useless except for a moon filter. All you really need are 3 eyepieces a low power (no greater than 35mm), a medium power (14-18mm) and a high power (no less than 5mm). You'll need a collimator. With Newtonians, you'll need to align the mirrors. It's best if you check it each night before you use it. Moving the telescope can knock it out of wack. A collimator helps you line everything back up. I have the Orion laser collimator. Here are some setup tips for setting up the scope for Goto use: 1. If you picked a city instead of entering a latitude longitude, and you don't actually live in the middle of the city (you just picked the closest one), do a factory reset of the computer and choose latitude-longitude instead. It's much more accurate. You can find the latitude longitude with a smart-phone app (e.g. Compass for Android) or by googling your address. You'll need the lat long in degrees, minutes, seconds (not the digital version like -117.0101). It should look like W 117 15' 12' Sometimes a city selection is too broad. I am about 20-30 miles outside the city I chose and it makes a big difference when the scope is skewing. 2. Make sure you're using the correct time/date settings including daylight savings time vs standard time. Use your cellphone time. 3. Instead of using 3-star align, use Auto-Two-Star align. It'll require you to know the names of the stars but it's much better. I use Google Skymap to find one of the stars in the list if I don't know the name or the ones I do know are obscured. If you use the 3-star align, chose bright stars that are on opposite sides of the sky and not in a line (a triangle pattern is preferred). For example, if you just used the stars in Orion, that's probably too small of an area of the sky. Choose one star in Orion (e.g. Betelgeuse), one in Gemini (e.g. Castor) and one in Cassiopeia. 4. When centering a star during alignment, defocus the star so it looks like a ball rather than a point of light. It'll be much easier to get in in the center. 5. When centering on the final star try to move the scope in the same direction as it was moving when it skewed to the star you chose. So for example, if it was moving down and to the left when it stopped, position the scope so that when you get it in the center of the view that you are moving it down and to the left when you stop. UPDATE 5/19/2016: I recently purchased a ZWO ASI185MC camera that I'm using with the 130SLT. The camera will easily come to focus when used in the 2" adapter. It will come to focus in the 1.25" adapter as well but it's a little closer to max in-focus. I'm getting pretty good images with it doing short exposure (<15seconds) and stacking. You'll want to use a Bahtinov Mask to focus. I purchased an Orion Accufocus which greatly helps with focusing the image without everything shaking. Check my reviews for the correct items. I also have it working with a computer (computer drives the scope). You need to install ASCOM drivers (6.2) and ASCOM drivers for the Celestron product line. Just search for "ASCOM drivers" on google. It's not necessary but it's nice for an all-in-one software package (Astrolive USB). I added some pictures I took of M51, M57, Jupiter and the moon. These were taken from my front yard about 5 miles from the city. The deep space objects won't appear that clear when viewing through the eyepiece (cameras pick up more light than our night vision does). Update 6/28/2016: One thing to really improve your goto results is to use "Precise Goto". It's undocumented in the manual. It's accessed differently than a regular goto. Press the "Menu" button. Then use the up/down arrows (6 &9 key) to find "Precise Goto". Then select "Database". Finally, choose from the object list type using the up/down arrows (e.g. Messier, NGC, Named Objects). So for instance, if I choose "Messier" and then enter the number for the Messier Object (1-110). It will calculate and give you a list of 5 bright stars with #1 being closest to the object. Select 1. The scope will slew to where it thinks it is. Center the bright star with the red dot finder and look through your eyepiece to see if it's centered there as well. Once it's centered in the eyepiece, hit <Enter>. The scope will slew to the object and there's a good chance it will be centered in your eyepiece. I use this feature with my camera and it almost always gets it close to the field of view. You should easily find the object in the field of view of a 25mm eyepiece (though it may be faint and fuzzy). ... show more
Reviewed in the United States on February 12, 2015 by Robert Johnson Robert Johnson

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