Monthly Archives: September 2015

Theron Optics Questa 8×42

I have been meaning to sit down and type up a review of the new Theron Questa 8×42 for a few days but just haven’t had the time until now. The Questa is a new model which has just been added to the Theron lineup and is available in both the 8×42 and 10×42 configurations. For those not familiar with Theron Optics they are a house brand for a company known at Predator Optics. Predator Optics sells a wide variety of sport optic and outdoor gear. The Theron Optics division has been in existence for the last 7 or 8 years and has been known for providing very good optical optical performance for the price (value). Prior to the introduction of the Questa their highest performing model was the Wapiti ED-APO. The Wapiti ED-APO, introduced several years ago, has many of the high end features such as dielectric prism coating and ED glass lenses. The Questa has the same features but takes performance to another level by introducing field flatteners in the eyepiece design.


Looking at the entire binocular market a potential buyer will find very few consumer-grade binoculars that utilize field flatteners. For many years only one or two companies, such as Nikon, utilized field flatteners in any of their binoculars. That small group got a little bigger several years ago when Swarovski introduced their Swarovision models. Since then one or two other models utilizing field flatteners have been introduced, the latest being the Theron Questa.

So, what makes the use of a field flattener so important? Well, what it does allow for is to have more of the field of view in focus. We often hear the phrase “edge to edge” sharpness. Field flattened binoculars often come the closest to being able to produce this level of performance. This then begs the question as to why more companies aren’t using them in their designs. As with any optical design there are drawbacks. The most often mentioned in this case is AMD (Angular Magnification Distortion) or “rolling ball” as it has been affectionately called as of late. AMD refers to a phenomenon where the image appears to roll as if across the surface of a ball when panning with the binocular. To counteract this to some extent manufacturers introduced some percentage of pincushion distortion. Such is the case with the Theron Questa. As someone that can notice AMD but is not bothered by it unless it is excessive I can happily report that the Questa displays very little of it.

So before we go into my impressions of optical performance, ergonomics, etc… let’s look at the basic features/specifications of the binocular.

8×42 model

- 22.6 mm of eye relief

- 425 foot (8.1 degree) field of view

- 822 grams (28.9 ounces)

- 6.2 inches tall

- Dielectric/phase coated, prisms

- Broadband Fully multicoated lenses

- ED glass objective design

- Nitrogren filled / waterproof

- 4 foot close focus

- 1.25 rotations from close focus to infinity counterclockwise (with an additional .25 rotation past infinity)


- Same overall specs and features as the 8x but with a 336 foot (6.4 degree) field of view, 18.5 mm of eye relief and an 812 gram (28.6 ounce) weight

Optical Performance:

As mentioned above the most prominent advertising feature with this model is the edge to edge sharpness. Does it really deliver edge to edge sharpness? Yes and no. As I have mentioned when describing various field flattener models in the past the image is sharp across more of the field of view than non-field flattened models. Is it edge to edge? Yes, in a sense it is however there is a small zone where the image loses a very small amount of sharpness. I would estimate the inner 3/4ths of the field of view is sharp and then there is about 10% of the field of view is slightly less sharp followed by the remaining 15% of outer edge of the image being as sharp as the central 75%. As has been discussed previously this “ring” is possibly where the AMD and pincushion distortion overlap within the image.

Apparent sharpness inside the sweetspot and at the edge is excellent. I have no difficulty pulling out the finest detail both at close focus and out on distant targets. CA control is excellent in the central 75% with a gradual worsening outwards. I would call it moderate at the very outer edge.
Apparent contrast is very good but a slightly warm to neutral color bias does influence this area to some extent. Apparent brightness is excellent and in comparison to just about every other binocular I have on hand it is notably brighter in challenging conditions.

When you combine all of these attributes then the resulting experience is truly extraordinary. The field of view is wide, so much of the image is in focus with the center, colors are accurately represented, CA is well controlled and the image is bright. I would use the term “panoramic” to describe the experience. Only a few of the binoculars I have owned in the past gave me a similar experience. The Meopta Meostar and Nikon Premier LX/HG/Venturer are the two that immediately come to mind because of the field flattener elements with the understanding that the Questas is a bit better because of the effective use of ED glass and the notably wider field of view. Definitely an “immersive” experience.


The largest objections to previous versions of this design was that the large oculars forced the eyecup diameter to be larger than average. This in turn forced consumers to use wider IPD settings to compensate to some extent. This created a less than ideal viewing comfort level for many individuals.


That issue has now been resolved with the Questa design. The eyecups are notably narrower at both the base and end which allows for narrower IPD settings and a much more appreciable comfort level. The eyecups have one intermediate setting between fully collapsed and fully extended and have a solid feel to their design.

The rubber armoring is smooth in texture and very pleasing to the touch. Unlike one of the previous versions of this design this model has narrower overall feel as a result. The texture of the rubber in combination with the thumb indents provides a similar feeling to that of the original Swarovski EL 8×32.

Both the focusing speed and tension of the Questa are close to ideal. As mentioned in the specs above it takes 1.25 revolutions to go from a close focus of about 4 feet all the way out to infinity. I tend to find binoculars with 1.25-1.5 revolutions to be ideal as they provide a nice compromise between too fast and too slow so long as the focusing tension is sufficient enough not overshoot “perfect focus” on any given object. This is the case with this model.

I have not noted any fit and finish issues with this model. Every component performs as intended (eyecups, central hinge, diopter, focuser, etc…). The diopter adjustment is located in the classic position around the right eyepiece. It does not lock but does have enough resistance to keep it locked in place.


Accessories include carrying case, neckstrap, objective covers and rainguard. The Questas carry a one year no-fault warranty and a lifetime manufacturer defect warranty. They have a listed retail price of $499 but are currently on an introductory sale price of $425.


Not really as my concerns with the previous versions have all been addressed. Some individuals might find the listed 28.9 ounce weight objectionable It is an ounce or so heavier than the premium models offered…

Swarovski SV 8.5 x43 – 28 ounces
Zeiss SF 8×42 – 27.5 ounces
Leica Ultravid Plus 8×42 – 27.9 ounces
Nikon EDG 8×42 – 27.7 ounces

Compared to some other popular mid-high priced models….

Leica Trinovid 8×42 – 28.6 ounces
Meopta Meostar HD 10×42 – 27 ounces
Zeiss Conquest HD – 28 ounces

I often find it interesting to compare specs on paper with various models. Keeping that in mind the Questa compares very favorably with models costing 4-5 times the price. Obviously, as fun as that might be, the real test is in actual use. I would encourage anyone to compare the Questa with any of the models listed above and report your experiences. There might not be as big of a gap as the price would dictate.

In summary, I find the Questa to be a bit of a game-changer for a variety of reasons. Yes, there were two models based on the same design from other companies but the eyecup size made “ease of use” much more difficult for me at least. This binocular has all of their benefits and none of their concerns. Optically this binocular has everything going for it…wide field of view, very good CA control, a huge sweet spot, excellent brightness and color and, ergonomically, I find it a pleasure to use.

The real question, as with many optics coming out of China, is whether or not the quality control is going to be good from unit to unit. With a sample of one in my possession I cannot comment on that issue but would be interested in others’ comments once more of these are purchased.

Two big thumbs up from me on this binocular!