Optics
The Evostar 72ED is an apochromatic doublet refractor telescope. It has a 72mm aperture and a focal length of 420mm, giving it an f/5.8 focal ratio. The optical system is made of two lenses, one of which is an FK61 extra-low dispersion (ED) glass element. This helps to reduce chromatic aberration, or color fringing, which can be a problem with refracting telescopes. However, FK61 ED glass is not very good, and doesn’t result in as much performance improvement or chromatic aberration reduction as most other ED glass types. Competing ED/apochromatic refractors use superior glass types such as FPL-51 or FPL-53, as well as equivalents like FCD1 and FCD100. These types of glass have a lower refractive index, resulting in less chromatic aberration and other benefits. This makes them a better choice for demanding astrophotographers and visual observers. An FPL-53 72mm refractor isn’t much more expensive than the Evostar 72ED, so if quality is a priority, it might be worth investing a little extra for a superior model.
The Evostar 72ED’s wide field of view makes it suitable for viewing deep sky objects with a wide-angle 2-inch eyepiece, where chromatic aberration is largely irrelevant. However, its small aperture essentially equates to half of a 70mm binocular. Unfortunately, close-up views of the moon and planets are not this telescope’s strong suit due to poorly controlled chromatic aberration and potential quality control issues with the optics. While images are generally sharp at low power, this telescope is not ideally suited for visual observation.
For deep-sky astrophotography, the Evostar 72ED’s chromatic aberration is not very prevalent, but be aware that at f/5.8, you’ll have to contend with field curvature, both with an eyepiece and with a camera. This issue can be addressed with a reducer or a reducer-flattener, which can also reduce the telescope’s focal ratio by up to 0.75x, depending on the camera used and your vignetting tolerances.
Mechanics
The Evostar 72ED is equipped with a 2-inch dual-speed Crayford focuser, which ensures smooth and precise focusing. This dual-speed focuser, similar to those used on many other Sky-Watcher telescopes, may not be perfect, but it is reliable and won’t slip under most loads. It can be easily motorized with a focuser such as the ZWO EAF. The focuser also features a Synta-style finder shoe bolted to the side, which allows for the attachment of a finder or guide scope.
The 2-inch set screw adapter that comes with the focuser, as opposed to the compression ring adapters found on the Evostar’s 2” diagonal and most quality 2” dual-speed focusers, can be a bit disappointing as it may leave a mark on your 2-inch diagonal or any 2-inch adapters you use, such as a 2-inch T adapter or a field flattener. Fortunately, some third parties sell compression ring replacements that fit the focuser’s M54 thread, and you probably won’t be loosening and tightening these screws very often. M54 thread adapters can also be used to directly attach a camera or another accessory to the back of the scope.
The Evostar 72ED also comes with tube rings and a Vixen-style dovetail plate, which allow you to mount the telescope on a compatible tripod or mount. The tube rings feature a 1/4-20 stud on one side to attach a piggyback camera, although this is generally not advised. Many users choose to use this stud to mount a guide scope or bolt a second dovetail to the top of the rings to attach a guiding setup or mini PC for controlling their astrophotography rig. If you wish, the Vixen dovetail could also be swapped for a Losmandy one.
Accessories
The Evostar 72ED comes with a carrying case, which protects the telescope from dust and damage during transportation and storage. The carrying case has a foam interior, which holds the telescope and accessories in place. The carrying case also has a handle and a shoulder strap, which make it easy to carry.
The Evostar 72ED does not come with any eyepieces, finder scope, or field flattener. These are optional accessories that you may want to purchase separately, depending on your needs and preferences.
The Evostar 72 also comes with a 2-inch dielectric diagonal, the same one supplied with most of their telescopes. It features a brass compression ring to hold your eyepiece accessories, as well as a corresponding 1.25-inch adapter with a compression ring. Its 99% reflectivity ensures minimal light loss at the eyepiece. However, you’ll need to find eyepieces that work well with the Evostar 72ED on your own.
Mount Recommendations
The Evostar 72ED is a relatively lightweight and portable telescope, weighing about 2.1 kg (4.6 lbs) without accessories. It can be mounted on a variety of tripods and mounts, depending on your intended use and budget. For visual astronomy, you may want to use a sturdy and stable alt-azimuth mount, while for astrophotography, you’ll need an equatorial mount.
When using the Evostar 72ED for visual observing purposes, a photo tripod might suffice, but we strongly recommend the use of an altazimuth mount such as the Vixen Mini Porta, Vixen Porta II, Explore Scientific Twilight I or Twilight Nano, or the Sky-Watcher AZ-GTi or AZ5. For astrophotography, the Evostar 72ED should be used with a mount that has motorized tracking, GoTo, and autoguiding capabilities. Here are some options:
- The Sky-Watcher HEQ5 Pro is an excellent German equatorial mount, widely considered to be one of the best equatorial mounts available, especially for beginner imagers. It’s incredibly lightweight and portable, hardly any heavier or larger in volume than the cheaper EQM-35i, but boasts considerably better capacity, better motors, and so on. It’s controlled via the SynScan app if you get the HEQ5i version, though a SynScan controller can also be purchased, and you can, of course, connect it to a PC.
- The Celestron Advanced VX is a relatively inexpensive GoTo equatorial mount, but it has some mechanical issues that we delve into in our corresponding review. It’s not perfect, but for visual use and astrophotography with less demanding and smaller aperture telescopes like the Evostar 72ED, it works quite well. You’re unlikely to even notice any of the issues that tend to come up with it. However, it won’t provide room for growth for a larger photography setup if you don’t know how to deal with its issues.
- The Sky-Watcher EQM-35i Pro is a fairly lightweight and portable GoTo equatorial mount, ideal for imaging with small telescopes and telephoto lenses like the Evostar 72ED. It uses high-quality stepper motors and is controlled via a smartphone or tablet. However, for astrophotography, you should probably connect it to a PC. With a weight capacity of around 10 to 15 pounds for astrophotography, the Evostar 72ED, a field flattener, and an autoguider will be well within this mount’s weight budget.
- The Sky-Watcher Star Adventurer GTi uses inferior servo motors, which are not as high quality as the steppers used in the EQM-35i or HEQ5i Pro. However, it features Sky-Watcher’s Freedom Find encoders, allowing you to manually move it around, which is ideal if you want to both image and observe with the same mount. It also features a built-in polar extension, illuminated polar scope, and is substantially more compact than a larger equatorial mount.
Should I buy a Used Sky-Watcher Evostar 72ED?
The Evostar 72ED is a durable and well-made telescope, and there is little that can go wrong with it that would not be obvious when buying a used unit. However, you should always inspect the telescope carefully before buying it, and look for any signs of damage or wear, such as scratches, dents, cracks, or dust on the lens, focuser, tube, or accessories. You should also test the telescope and its accessories for proper functioning, such as smooth and accurate focusing, secure mounting, and clear and crisp images. You should also check the warranty and return policy of the seller, and compare the price of the used unit with the price of a new one, to make sure you are getting a good deal.
Alternative Recommendations
The Sky-Watcher Evostar 72ED is a decent telescope, but it is not the best option for its price range. It has nothing wrong with it mechanically, and it is pretty much identical to most cheaper ED refractors, with a decent lens cell, focuser, and mounting rings. However, the scope could be better optically, and the price could be lower. We recommend it, but there are better options to consider, especially for astrophotography. Here are some of the alternatives that we suggest:
- The Sharpstar 61EDPH features a triplet f/5.5 objective lens with an FPL-53 lens element, for sharp and low-chromatic aberration views and images. It can also be reduced to f/4.5 with a 0.85x reducer, and it has a large image circle of 44mm at f/5.5, which means that vignetting is not a big problem with a reducer and larger sensors. It is fairly small and lightweight, though heavier than a doublet refractor because of the extra lens element.
- The William Optics Zenithstar 61 and the Apertura 61EDR are similar in specs, and both feature FPL-53 glass and mounting accessories, along with dual-speed focusers. These scopes are sharper than the Evostar 72, though they have less light-gathering power and lack proper tube rings.
- If you are interested in Newtonian reflectors, a number of 6-inch f/4 options are available, namely the Sky-Watcher Quattro 6-inch f/4 and the Apertura and GSO 6” f/4 Imaging Newtonians, also sold under other brand names, such as Orion, Astro-Tech, and Meade. While collimation and coma correction can seem daunting compared to a simple refractor, these scopes are faster in f-stop than almost any good refractor can possibly be, and they also present nice wide-field views with a suitable eyepiece.
Aftermarket Accessory Recommendations
If you plan on using the Evostar 72ED for visual observation, you’ll need some eyepieces. There are numerous options available, including the Red Line and Gold Line eyepieces, Plössl GSO Super Views, Agena Starguiders, and the Explore Scientific 82 and 68-degree range, among others. All these eyepieces will work well with the Evostar 72ED. A 2-inch wide-angle ocular is ideal for low-power sweeping. If you’re using the Evostar 72ED for visual observation primarily at low power on a manual mount, you may not even need a finder at all, but a cheap red dot finder, such as one from SVBONY, might be worth considering and will slide right into the finder shoe on the Evostar 72ED’s focuser.
For astrophotography, the Evostar 72ED will require a number of additional items. Of course, you’ll need a camera and any corresponding filters or adapters. You’ll also likely want a reducer-flattener or at least a field flattener, such as Sky-Watcher’s 0.85x model, to clean up the edges of the field of view, speed up your focal ratio, and widen the field for the largest deep sky objects. Your choice of camera will depend on your personal preference and budget, but you might want to consider a dedicated astronomy camera or a modified DSLR camera, which offer higher sensitivity and lower noise than regular cameras.
For longer exposures, you’ll need an autoguiding system, which consists of a guide scope, a guide camera, and guide software to monitor and correct the tracking errors of the mount. The Evostar 72ED could also benefit from a motor focuser, such as the ZWO motor focuser. You could also consider a Bahtinov mask to assist with focusing. All these accessories are à la carte, and it’s really up to you to decide what to buy, given the wide variety of options and prices.
Astrophotography Capabilities
The Evostar 72ED is ideal for capturing large nebulae and star clusters across the night sky. You can also capture the Andromeda galaxy and galaxy groups, but with most cameras, you’re probably not going to have sufficient image scale or resolving power to go after detail in many galaxies. They’ll appear quite small in the frame, as will most globular clusters and planetary nebulae. These objects require longer focal lengths, very good resolution, as well as accurate tracking and guiding. The Evostar 72ED’s optics and small aperture, combined with its short focal length, make it a poor choice for smaller deep sky objects. Bluish to purplish halos may appear around bright stars, but it’s not as bad as an achromat, and if you’re doing narrowband imaging, this problem can be ignored entirely.
Of course, you’ll need to purchase the prerequisite equipment mentioned in the aftermarket accessories section and pick up a suitable German equatorial mount to use the Evostar 72ED for astrophotography.
What can you see?
The Evostar 72ED is a good telescope for wide-field views of the sky, but it has some limitations when it comes to observing deep-sky objects. Its 2” diagonal and short focal length make it ideal for sweeping the sky with a low-power eyepiece, but it does not have a lot of light-gathering area available to it. To put this in perspective, a pair of 15×70 binoculars can collect the same amount of light as two Evostar 72EDs, one for each eye. A pair of 10×50 binoculars is comparable in light-collecting power to the Evostar 72ED. Therefore, it is not very good for seeing faint or small objects, such as globular clusters, planetary nebulae, or galaxies.
The Evostar 72ED can show you some of the bright and colorful open star clusters, such as the Double Cluster, M11, the Pleiades (M45), and so on. However, they are not as impressive as they are in a larger scope, and the brightest stars of magnitude 1 or 2 also show some blue to purple halos around them, a consequence of chromatic aberration. Globular clusters remain unresolved fuzzy balls, and most planetary nebulae are invisible, or at best, indistinguishable from stars with this scope as they fade from view at high power. Galaxies are very difficult to see, and you may only be able to make out the dust lanes in M31 or M82 with great difficulty unless you have pristine skies free of light pollution. Most other galaxies are indistinct smudges, devoid of detail or shape, and mostly invisible if you have any light pollution at all. You can forget about seeing them at all.
The Evostar 72ED is a little less exciting for observing the Moon and the planets than a typical small refractor with a longer focal ratio and/or better ED glass, which would enable sharper views. The phases of Mercury are indistinct at best with this scope, and Venus presents a massive purple halo around it, though you can see its phases fairly easily. The Moon delights with thousands of details, but the smallest of them are not as crisp or well-rendered as with a bigger or sharper telescope. Mars is little more than a reddish ball, and the majority of the chromatic aberration is concentrated towards the extreme blue and red ends of the spectrum. Unfortunately, Mars is, of course, a rather reddish object, and its low-contrast surface features are not rendered well by this scope as a result. It is also hard to see the polar ice cap, mainly due to the chromatic aberration seen surrounding the Red Planet with this telescope.
Jupiter shows its equatorial cloud bands with the Evostar 72ED, but it lacks fine detail in them, and the Great Red Spot may be hard to see. The moons of Jupiter, that is, Io, Europa, Ganymede, and Callisto, can technically be resolved with a telescope of this size, but in practice, they are indistinct fuzzy dots, and their shadows do not show up at all on the disk of Jupiter during their transits.
The Evostar 72ED will show you the rings of Saturn, and possibly the Cassini Division within them, though with Saturn’s decreasing ring tilt until 2025, the Cassini Division will be harder to see, and will continue to be so for the remainder of the 2020s. Even at the rings’ widest tilt, the Evostar 72ED is not as up for the task as a higher-quality telescope of this aperture. A few of Saturn’s moons can be seen, and perhaps some dull cloud bands on the planet as well. Uranus and Neptune are fuzzy bluish dots, devoid of moons, resolution, or detail, if you can even find them at all. Pluto, of course, requires a much larger instrument to be seen at all
