Acuter DS20-60X80A Spotting Scope Review

For me it is always nice to try out some equipment from a manufacturer that I have not used before and so when I was contacted by the UK distributors of Acuter asking me if I would like to try out their new scope, I jumped at the chance. Below are my thoughts and full review of the Acuter DS20-60X80A Dual Speed Spotting Scope:

The Body

Build Quality
This angled (45 degrees) 80mm Acuter spotting scope currently the only scope in their new DS-Pro series (100mm and ED variants available soon) and features a newly designed body that I think looks great. The Acuter DS20-60X80A is made from aluminium and feels really solid and robust and is covered in a very hard rubber armour, that as the name suggests will protect it from day to day knocks and bumps. This armour also has the added benefit of dampening down any sounds from objects striking against it - I am thinking of things like watches or a wedding ring, this sometimes happens when I grab hold of my scope and this sound could frighten away easily spooked birds and other wildlife.

A nice touch and one that not every scope in this price range feature is a mounting plate that fits onto the main body of the scope with a collar that goes right round the barrel. This can be loosened via the silver knob on top of the body meaning that the spotting scope can be rotated by a full 360° to change the orientation of the eyepiece. This can come in handy if you have to place your tripod on uneven ground or if you use something like a Gimbal tripod head to mount your scope to your tripod.

The mounting plate itself has three different locations where you can attach your tripod head to, so that you can get the balance exactly right. This can really help if you are digiscoping for example where the extra weight of the camera and adapter can really upset the balance of your scope on the tripod. I also like the fact that this plate is deeply grooved which really helped to keep it secure on my tripod head plate.

At the end of the barrel is a extendable Sunshade, or as it is sometimes called a Dewshield that is used to either protect your lens from moisture or from the sun which can spoil your view. The shade also has a raised sighting line on it that can help you with lining up objects. The shade itself extends from the barrel with enough friction to keep it in place, yet it not too tight as to make adjusting it difficult or awkward.

Waterproof
Obviously I did not test this, but Acuter state that this scope is waterproof. The supplied "stay on" cover (case) will also help with protecting your scope from the elements (see below)

Focusing
The Acuter DS20-60X80A comes with a Dual speed focussing mechanism which is something that I really like. You use the larger focussing wheel to quickly get close to the correct focus and then the smaller (15:1 Ratio) wheel to fine tune the focus to get what ever you are looking at as sharp as possible.

On the scope that I was testing, they both turned really smoothly and located on the side of the scope they are easily reachable. The wheels themselves are also covered in rubber and is deeply grooved to help with grip.

Rating for Body Construction Quality: 7/10

Weight
At 63.5oz (1800 g), it must be said that these are not the lightest 80mm spotting scopes out there. Aluminium is used for the body which is fairly light as well as pretty robust. At the very top end of the market, with scopes like the incredible Kowa TSN-880's for example they use very lightweight (and very expensive) magnesium bodies to keep the weight down. For comparison I have included the weights of other similar sized scopes below:

• Nikon EDG Fieldscope 85-A: - This 85mm scope weighs 71.6ozs (2030g)
• Barr & Stroud Sahara 20-60x80 This 80mm scope weighs 47.97ozs (1360g)
• Kowa TSN-881 - Incredibly this 88mm scope only weighs 53.6oz (1520g)

I must add though that weight alone can sometimes be a little misleading as some of the lightest scopes on the market are also amongst the cheapest (and worst) - this is because some very light spotting scopes are only this weight because they use sub-standard materials in their construction that may be lighter, but are definitely not as durable. For me I'd rather have a slightly heavier scope like this Acuter that feels both robust and durable , than a very light "plastic" scope that does not feel like a quality optical instrument that feels like it could break with the slightest knock.

Rating for Body Stats: 7/10

The Optics

The Prisms and their coatings
Acuter use high quality BaK-4 prisms on this scope as opposed to the cheaper BK-7 ones sometimes found on cheap spotting scopes. This superior optical glass helps to produce clearer image and obviously this is what you want from your scope.

Lenses
The Acuter DS-PRO uses an achromatic lens - what this means is that the lens is designed to limit the effects of chromatic as well as spherical aberrations. In general achromatic lenses are corrected to bring two wavelengths (most often red and blue) into focus in the same plane. Acuter don't go into detail, but the most common type of achromat is the achromatic doublet, here the lens is actually composed of two individual lenses, each made from glass with a different amount of dispersion and then joined together. Usually one element is a concave lens and has a relatively high dispersion, while the other, a convex element has lower dispersion, they are then shaped so that the chromatic aberration of one is counterbalanced by that of the other so that the two wavelengths are brought into the same focus. Update: I have got confirmation that the objective lens is indeed an air-spaced achromatic doublet.

The lenses that are used on the Acuter scope have also been fully multi-coated which means all air-to-glass surfaces have received multiple layers of anti-reflective coatings which increases light transmission to produce a brighter image and therefore better low light performance.

Anti-reflective coatings can make a really difference on the brightness of the image produced. It is not uncommon for a scope with a smaller objective lens, but high quality anti-reflection coatings to outperform one with a much larger objective lenses, but with fewer or no coatings. Beware of these lower quality optics that will often only add multiple anti-reflection coatings to the outer surfaces of the lenses (Multi-Coated) and cheaper still are scopes that only have a single layers of anti-reflection coating added to the outer lenses (Coated). The very cheapest optics have no anti-reflective coatings at all and I highly recommend staying well clear of these.

The table below shows Transmittance by type of coating:

Rating for Optical Components Quality: 6/10

The 20x-60x (8-24mm) Zoom Eyepiece

This Acuter Spotting scope comes with a 20x-60x (8-24mm) Zoom Eyepiece that due to the wide zoom range should be suitable for a whole range of uses. The eyepiece is multi-coated to help with light transmission as well as image contrast. The eyepiece fits into the body of the scope using a standard 1.25" push-fit socket and it is therefore easy enough to find many other eyepieces to fit this scope depending on your requirements. The fit is very snug and you have to push quite hard to get it fully into the scope, but once in you have the added confidence that with the lock ring it is secure. This tight fit will also help to ensure that the scope remains waterproof.

A nice tip when fitting an eyepiece that has a tight fit is to use a touch of lubrication (even saliva will work) on the barrel. This will help the barrel pass the rubber O-ring that ensures that the scope remains waterproof.

The magnification is 20-60x with this 80mm scope and would be 16-48x with a 65mm objective lens and 22-67x with a 100m lens.

The Eye Cup
The fairly standard twist-up eyecup on this 20x-60x looks to be made from metal and has a fairly thick soft rubber coating on top of it that makes it feel pretty comfortable even when pushed quite firmly against your face.

The twist-up mechanism on the eyecup is really smooth and works well. Whilst it does not have any fixed intermediate stops, there is enough friction to stop it at any distance in between fully retracted and fully extended to give you as much flexibility as possible to get the full field of view without any vignetting.

Digiscoping
Something that I really like is that you can screw off the eyecup that then reveals a thread and you can then get a T-mount adaptor that is available to fit this thread. What this means is that you can attach an SLR or DSLR Camera to theis T-mount for digiscoping.

Optical Stats

Field Of View

Using the included 20x-60x (8-24mm) Zoom Eyepiece the field of view at 20x magnification is 37m @ 1000m (111 feet@1000 yards) and 19m @ 1000m (57 feet@1000 yards) wen using the eyepiece at full 60x magnification. To try and put this into some sort of context, the FOV is as good as the equivalent Nikon FEP-20-60x eyepiece attached to the very top of the range Nikon EDG Fieldscope 85-A, which has a field of view ranging from 38-19 @ 1000m

Close Focusing Distance
With a focal length of 480mm, it's close focussing distance is 6.5m (21.3ft), which is not bad at all - for comparison the flagship TSN-880 series of spotting scopes from Kowa has a minimum focusing distance of 5m 16.4ft), which is better, but just remember the Kowa will cost you a whole lot more money.

Eye-Relief:
The maximum eye-relief of 20 mm is very good and should be more than enough for most people who wear glasses.

Rating for Optical Stats: 7/10

Image Quality

Image Brightness
Testing was carried out on a dull and overcast day and on a bright sunny day and in terms of image brightness, these were about the same as my 80mm benchmark spotting scope, but understandibly not quite as bright as the 100mm Celestron Regal scope that I also had with me at the time and so because of this I rate them just above average in this department.

More about Image Brightness & Low Light Performance
Good light gathering ability is important because quite often you will find yourself in situations where the lighting is sub-optimal, especially in thickly wooded or forested areas, early in the morning just before or at sunrise or late afternoon when most birds and other animals are at their most active. Scopes with larger objective lenses have the potential to take in more light and therefore have the potential to produce a brighter image.

But no matter how much light your spottingscope gathers, it is no good if that light is not passed onto your eyes (transmittance) and this depends hugely on the quality of the glass and optical coatings and not just the size of the objective lens. Good coatings on the lenses and the prisms can in some cases double the amount of light that gets through the scope, when compared to those that have none or poor quality coatings.

Color Fringing
To check for any color fringing (chromatic aberration), I focus on light coloured and white objects sitting in front of a dark backgrounds as this is where it is easiest to notice if there is any on the objects edges. To my eyes and even though these Acuter scopes use achromatic lenses, I could just notice a very small amount of colour fringing. This is where scopes that use ED (extra low dispersion glass) can make a difference, but having said that, the amount of chromatic aberration was very minimal and only really noticeable if you are looking for it.

Softening
There was a small amount of softening of the image on the periphery of the view. Like the colour fringing, it was not bad, but if you are looking for it, you can notice it. Comparing this amount of softening to a top of the range scope, you can notice the difference and I guess this is why high end spotting scopes can cost 10x the price of these.

Contrast & Colour Reproduction
I thought that the amount of contrast was good and the colors that are produced look and feel pretty natural.

Overall I would rate the view through this Acuter as being above average and easily as good as and better than many that I have used in their price range.

Rating for Image Quality: 7/10

Included Extras & Attention to Detail:

Carry Case
The included "stay-on" carry case is a nice touch as most scopes come with a carry case, but not all come with one that can be kept on the scope when you are using it. This allows you to add extra protection to your scope from the elements and the padding will also protect it a little should you bump or scratch it.

The case itself is fairly well made and will definitely protect the scope from light rain, but is not quite as well padded as some others that I have used. It has Velcro fastened openings for the tripod adapter as well as one that will allow you to adjust the focusing wheels. There is also an eyepiece and objective lens hood that can be close when transporting your scope and then quickly opened when you use it.

You also get asmall soft case to protect your eyepiece when you have removed it from the scope. It is simple, but looks well made and is closed with a velcro fastened flap. You can attach it to you bag with a clip that is attached to the back of it.

Lens Covers
The eye-piece cover is a metal tube that covers the eyepiece and can be screwed onto the body of scope. It also has a screw on cap which means you can look through the scope with it still attached (You cannot however change the magnification with it on).

The hard plastic objective lens cap fits rather lightly onto the end of the scope and I could see it being knocked off accidentally on occasions.

Rating for Extras & Attention to Detail: 6/10

Conclusion

Strong Points: With a recommended retail price of just �249 and now available for much less, I think the biggest strong point is the fact that you get what must be said is overall a really good quality and high powered scope for what is a very good price. The quality of almost every aspect of this scope is well above that of other scopes in this price range and with features like the dual speed focuser, fully multi-coated optics and a tough waterproof body you are getting plenty of scope for your money.

Weak points? There is nothing really bad about this scope and and considering it's price, this is pretty remarkable. I feel slightly awkward comparing it to ones that cost almost 10x as much, but if I was able to improve it, it would be nice for it to have a slightly less softening of the image on the edge of the view and if ED (extra low dispersion glass) was used, I am sure that what little amount of color fringing there is would pretty much disappear. But then if they were to do this, the price tag would have to increase.

Ideal Uses: With the included 20x-60x (8-24mm) Zoom Eyepiece, this scope is ideal for a variety of uses including birdwatching,general nature and wildlife observation, target shooting and the fairly large 80mm objective lens means that you can even use it for for astronomy.

So to sum up, I feel that the Acuter DS20-60X80A Dual Speed Spotting Scope well outperforms it's price tag and so if you are looking for a really good entry-mid level spotting scope, the Acuter DS20-60X80A would make an ideal choice.

Acknowledgements

I would like to thank Optical Vision Ltd. the UK distributor of Acuter Spotting scopes for sending this one to me to review. I would also like to point out that this and all the other reviews on this site are my opinion and are not influenced in any way by manufacturers, distributors or suppliers.

More on Acuter: Acuter is the terrestrial optics brand of Synta Technology Corporation, the owner of Sky-Watcher, a world-famous, market leading brand of Astronomical Telescopes. You can also read about this scope on the Optical vision website.