Choosing The Best Spotting Scope For Astronomy in UK
Many people prefer to use a spotting scope rather than a telescope and we can understand why that’s the case. A spotting scope might not have quite the range of a telescope but it will weigh less, be far more portable, more versatile and cost less. If you’re not sure whether to buy binoculars, a spotting scope or a telescope, this article is for you.
Spotting scopes are often described as mini telescopes but that’s only half the story. Telescopes are designed for one task – Stargazing. Whereas a decent spotting scope can be used to study the surface of the moon, some of the moons of Jupiter and the rings of Saturn.
But if it’s too cloudy to see the heavens, a spotting scope can be used for bird watching, hunting, whale watching and many other activities where a magnified image will help.
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What To Look For When Buying A Spotting Scope
There are so many spotting scopes to choose from, with prices to suit pretty much every budget, so what do you need to look out for? As with any optical equipment there are a few points to consider. Below we’ve put together a list of the main points you’ll need to consider before you rush out and purchase your spotting scope.
What’s Best; Binoculars, Spotting Scope Or Telescope For Astronomy?
Although these three all offer similar functions, they have very different applications. Let’s take a few minutes to compare all three and get more of an idea which is best for your personal situation.
Of the three, binoculars offer the most portability, they are lighter, easier to carry and most don’t need a tripod at all. However, they lack the level of magnification necessary to see any celestial beings in any detail. With any magnification over 10X you’ll need a tripod so to increase the magnification you lose some of the portability and increase the weight substantially too.
Spotting scopes offer some of the manoeuvrability of binoculars with increased magnification and the option of an angled lens for comfort. Many spotting scopes have zoom capability which is like a telephoto lens on a camera and allows you more viewing range but less field of view than binoculars. If you get fed up with stargazing, a spotting scope can be used for so many other hobbies that unless you’re fully committed to astronomy, a spotting scope will be your best choice.
The primary function of a telescope is stargazing, and as such it does it extremely well. A telescope gathers far more light due to its large objective lens however, that lens makes the telescope far heavier than the other two, and means you’ll have to remain in one place too. Telescopes are often far more powerful than either binoculars or spotting scopes, but that power comes at a price.
Which Is Best?
Budget wise, telescopes will cost you more money and they’re astronomy specific so if you are 100% into astronomy it needs to be a telescope. But, binoculars can be used for many activities including bird watching, whale watching, wildlife watching and even taking to sports events. Spotting scopes are kind of halfway between the two, some portability, higher magnification than binoculars, but lighter than a telescope so can be moved around and used during daylight hours for more than just astronomy.
That pretty much sums it up and ultimately the choice is yours, but we believe that of the three, a spotting scope offers the best value long term. For all of the reasons quoted above, if you want a direct comparison between spotting scopes and telescopes, check out our article on the differences between the two.. However, if you’re fully committed to studying the stars, then you need a telescope.
Spotting Scope Buyers Guide
If you do decide a spotting scope is the way to go, there are a number of points to consider and we’ve listed them below to help you make the right decision and get the most from your scope. We’ll take you through everything you’re likely to need to consider and some of it might seem basic but we want to be thorough.
Straight Or Angled Lens?
Which type of lens should you choose for your spotting scope, straight or angled? It’s a matter of personal preference really. However, one point worth considering is, an angled lens will allow you to look at the stars without looking up for extended periods of time and placing excess stress on your neck.
Because of this, we would definitely recommend anyone with neck issues to go for an angled spotting scope.
It is also possible to purchase spotting scopes with interchangeable lenses, giving you the best of both worlds. Angled lenses are easier to attach a camera too (if digiscoping is something you’d like to try).
Spotting Scope numbers
Probably one of the first things you’ll notice when you start looking at spotting scopes are the numbers. You’ll notice sets of numbers like 4 X 25 or 20-60 X 60. The first number is the amount of magnification, followed by the diameter of the objective lens in millimetres. So 4 X 25 has a magnification of 4 times with a 25 mm objective lens.
If the first set of numbers are hyphenated, it indicates a zoom feature. So 20-60 X60 has a magnification starting at 20 times, zooming to 60 times with an objective lens diameter of 60 mm.
The objective lens is the lens furthest away from your eye and closest to the object you’re looking at. It’s an important feature as the objective lens is the only way light can enter the scope to illuminate the objects you are looking at. This is of great importance for the astronomer because stars in general aren’t as bright as objects illuminated by our sun.
So, the larger the objective lens, the brighter the objects viewed through the scope will appear and therefore, the easier they will be to see. But, as the objective lens size increases, so does the overall size and weight of the scope. The weight of the glass that’s used to make the lens increases with its size.
This isn’t so much of a problem if you always intend to use the scope at home, in one position. But if you want to move around outdoors, then the overall size and weight need to be taken into consideration.
Most spotting scopes are supplied with a tripod or similar support stand. This might be sufficient for your purpose, but you might want to consider a sturdier, stronger tripod that gives you better stability especially if you never intend taking the scope outdoors.
Any spotting scope will probably weigh more than a pair of binoculars and if you intend to use it indoors weight isn’t too important. If however, you intend to take your scope outdoors at any point remember it will need to be carried. Along with the tripod or any other support.
Some spotting scopes come with a fixed eyepiece, this means the level of magnification is set and cannot be altered at all. Others come with interchangeable eyepieces that can be replaced with others of greater values of magnification. Others still come with a zoom eyepiece which saves you the bother of having to change eyepieces or carry extra kit around with you.
20-60 magnification is a good starting point as it gives you a magnification of 20 times, rising to 60 times. This means that objects will appear between 20 to 60 times larger through the lens than through your eye.
This is a term that’s often quoted in relation to optical equipment but in all honesty, it’s pretty redundant in terms of spotting scopes. Close focus is how close to an object you can be and still see it clearly. With magnification levels of at least 20 times, and given the fact you’re looking at objects in outer space, the close focus isn’t really relevant.
When it comes to spotting scopes, there are two main types of focus systems. One has a small knob usually located close to the eyepiece on top of the scope. The other has a collar that twists the barrel. The small knob is more fiddly and takes longer to set up, but it does allow for more accuracy and precision.
This is the soft plastic or rubber rim that surrounds the eyepiece and is designed to keep your eye comfortable. The eye cups are usually adjustable either by folding or twisting them up or down.
There is a position where your eye is a certain distance from the lens and you can see the full image with no dark circles or loss of the image. That position is known as eye relief. In most cases eye relief isn’t all that important, unless you wear glasses. If you do wear glasses all the time, you’ll need a scope that has long eye relief. This allows the same positioning but with room to accommodate your glasses comfortably too.
Waterproof & Fog Proof
If you only intend to use your spotting scope indoors, waterproofing isn’t an issue. But if you want to use it outdoors then it makes sense to buy a waterproof and fog proof scope. You’ll often see in the specs “purged” this means all of the oxygen has been purged from the lens tube and replaced using an inert gas.
Nitrogen or argon are the usual gases of choice because these contain no moisture and will not fog up due to temperature fluctuations. As the gas is sealed inside the lens tube, nothing else can enter. Which means the scope will remain dust, dirt, mould and water free.
Light transmission is determined by the quality of the glass used to construct the lenses and prisms used in your spotting scope. There are a number of points to understand here, starting with the glass construction and then the various coatings applied to the lenses.
BAK-4 glass has the least imperfections of any optical glass which means the best light transmission available. It is used in top quality prisms for both binoculars and spotting scopes. As it is a top quality high precision glass, it adds to the cost of the scope but it is definitely worth paying the extra for, especially for astronomy.
This is still quality high precision glass but with slightly more imperfections than BAK-4 glass. BK-7 is found in less expensive binoculars and spotting scopes.
The actual lenses should be made from HD (high density) or ED (extra-low dispersion) glass. Both of these glasses improve the transmission of light and help to reduce haloing or colour fringing.
There are a number of levels of lens coatings, with the best in terms of light transmission being Fully Multi-Coated (FMC). FMC lenses have every surface coated with multiple layers of light transmission improving coatings.
As with binoculars, spotting scopes are made in two different configurations when it comes to the prisms. Porro Prisms and roof prisms, with the main differences being, roof prisms are generally more compact, lighter, more robust and easier to fully waterproof than Porro prisms. On the downside, roof prisms tend to be more expensive and have a slightly less clear image.
A good quality spotting scope capable of being used for stargazing will cost a considerable sum of money. Not as much as a telescope but still a considerable amount. It should have a good warranty. All of the better quality spotting scopes have warranties, with the best having lifetime warranties.
This means as long as you own the scope and you’re the original owner, it will be repaired or replaced by the manufacturer in the event of an actual problem or even accidental damage.
What Is The Price Of A Spotting Scope?
As with all things nowadays, prices for spotting scopes range from the ridiculous to the sublime. We would never recommend a cheap scope as you really do get what you pay for. The prices are fairly similar whether you choose a straight or angled lens scope. Any differences in price are dictated by quality and performance.
Prices for spotting scopes range from around £100.00 to £5,000.00 with a decent 20-60 X 80 scope complete with a lifetime guarantee costing around £250.00.
Before you purchase your spotting scope for astronomy, it will pay to do your homework. Only buy from a reputable source and always buy a well known brand. You will be sure of quality if you buy one of the following brands
- Delta Optical
- SIG Sauer
- Yukon Advanced Optics
These are some of the better known and well trusted manufacturers that have been in the optical equipment business for many years and have a proven track record for excellence.
Frequently Asked Questions
Spotting scopes are good for many hobbies and activities including astronomy, bird watching etc. A telescope is better for astronomy but that’s all they’re good for whereas a spotting scope is far more versatile.
A spotting scope should have a magnification of between 15x to 20x this will be powerful enough to stargaze.
With a spotting scope you will be able to see the rings of Saturn and some of the moons of Jupiter.
You should have no difficulty seeing Mars using a spotting scope.
Spotting scopes are considerably more powerful than binoculars.
There are two main differences between a monocular and a spotting scope. Spotting scopes are larger than monoculars and they also have a far greater magnification level.