Vortex Diamondback 20-60x80 Spotting Scope vs. Vortex Viper HD 15-45x65 Spotting Scope

For those who enjoy hunting or target shooting at very significant ranges, adding a spotting scope to your gear can be a great way to help identify and locate targets or games. We’re going to take a look at two spotting scopes from Vortex, the Diamondback, and the Viper.

Vortex Diamondback 20-60x80 vs. Vortex Viper HD 15-45x65

Both the Diamondback 20-60x80 and the Viper HD 15-45x65 are from Vortex, and they represent two different lines of spotting scopes. The Diamondback is going to be what many people would consider a “budget” model and will be the most affordable. The Viper line is considered a mid-range variant, and as such, will cost more than the Diamondback line.


This means that while the optics will be relatively similar, you should expect to see some differences in performance. To evaluate these two scopes as evenly as possible, we broke the criteria down to the design, factors affecting operation and performance, and general stats and specifications. The most significant factor will be your own consideration of what is important to you in the spotting scope that ends up in your pack.


Viewing Angle

Both the Diamondback 20-60x80 and the Vortex Viper HD 15-45x65 come with angled viewing. This provides a more comfortable viewing experience than a straight viewing angle. The only downside to this is that they will take up slightly more room in a pack than straight models.


The Diamondback is only available in an angled view design, while the Viper can be found in both an angled and a straight-view variant. While this won’t be very important to some people, it might be a crucial distinction to you, depending on your use and needs.



There is a clear difference in the magnification power of the two spotting scopes. The Diamondback provides 20 to 60x, while the Viper provides a magnification of 15 to 45x. You might wonder why the more affordable spotting scope has such a vastly superior magnification ability, but looking through the scope will provide a clearer picture.


While the Diamondback scope provides significantly higher magnification, that magnification is also needed to get a clear picture of targets at a considerable distance. The Viper has a lower magnification limit, but it also provides a clearer picture which means you don’t need as much magnification to get good ranging and shot information.

Objective Lens Diameter

The objective lens is a significant factor for many people. While a large objective lens lets in plenty of light for clear imaging, it also adds considerable size and crucial weight to the scope. In this case, there is a 15mm difference in the two scopes’ objective lens sizes, which is nearly almost three-quarters of an inch.


The Diamondback sports an 80mm objective lens, while the Viper is able to perform slightly better while only needing a 65mm objective. While there’s less glass in the Viper, that glass is higher-performance.

Field of View

The field of view for both the Diamondback 20-60x80 and the Vortex Viper HD 15-45x65 are considerable and we have no complaints. The only difference is in the numbers, and the distances you plan on operating within.


Field of view with the Diamondback at 20x is 105.0' @ 1000 yd (35.0 m @ 1000 m) and at 60x is 51.0' @ 1000 yd (17.0 m @ 1000 m). For the Viper, you get a very similar 136.5' @ 1000 yd (45.4 m @ 1000 m) at 15x, while 45x gives 67.8' @ 1000 yd (22.6 m @ 1000 m).

Minimum Focus Distance

If you occasionally need to spot moving objects that may close the distance between you, a short minimum focus distance is handy. Both models stack up similarly, with only one foot of distance difference between the two. The Diamondback has a minimum focus distance of 22.0' (6.7 m), with 23.0'  (7.0 m) for the Viper.

Exit Pupil Diameter

Surprisingly, even though the differences are only fractions of a millimeter, they can feel much larger. While the Diamondback sports a 4 mm diameter at 20x, out at 60x it becomes just 1.3 mm. Sufficient, but the Viper has the edge side-by-side, with 4.3 mm at 15x and 1.4 mm at 45x.

Eye Relief

Surprisingly, the eye relief on the Diamondback is not only a wider range than the Viper but more comfortable as well. The Diamondback has an eye relief of 16.5 to 20.0 mm, and the Viper has just 19.6 to 17.8 mm. For those that are looking for comfort as a significant factor, this can be a prominent consideration.



Both the Diamondback and the Viper are fog-proof. The Diamondback housing has been purged and nitrogen-filled, while the Viper swaps out the nitrogen for argon.

Water resistance

The Diamondback and the Viper are both waterproof spotting scopes. You can take them out in the elements, and hunt in the rain or snow, without worrying about functionality.


Tripod Mounting Thread

If you like to set your spotting scope up on a tripod for easy viewing and handling, these two make it easy for you. No special mounting is needed, both use a standard 1/4"-20 mounting thread.


The Viper is marginally shorter, at 14” than the 14.8” Diamondback. While large, they aren’t inconvenient, and the relatively low weight makes them great additions to your gear.


You might be surprised which scope will save you weight in your pack, particularly with the weight of the objective lenses, but with the Diamondback weighing in at 2.9 lb / 1.3 kg, and the Viper tipping the scales at 3.7 lb / 1.7 kg, those who need to pack lightly should be looking at the Diamondback strongly.

Wrapping Up

Overall, these two scopes are incredibly close to each other in performance, though the Viper does edge ahead in a few areas, such as the image clarity at maximum magnification and the exit pupil distance. Ultimately, both are great spotting scopes, and no matter which you decide on you’ll be getting a high-quality piece of gear.


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