This is a mid price binocular, selling for $379 for the 8x version I have. I am pretty impressed by the abilities of the current $4-500 binoculars to deliver the goods far above and beyond their asking price. This glass is a more reasonable comparison to the ZEN ED 2 and the Theron Wapiti APO-ED and a couple of others. There are some differences here that will help separate the three.
Kruger takes a little different approach to making things in China The Kruger Corporate Headquarters and factory (one of them) is in Sisters, OR, a bit over a two hour drive north of me. I have been there twice. This is where they do all their optical design. They design, engineer, build the prototypes (they have complete CNC controlled manufacturing ability), and do product development here. They are currently building a couple of riflescopes in Sisters. Some of the parts come from their China facilities. They intend to expand as much of the assembly work at the Sisters site as they can. Kruger started out with a couple of Leupold engineers who started Pacific Rim Optical (PRO). This is a division of the now larger parent Kruger Optical and wholly owned by Kruger. PRO makes optical glass for almost any sort of optical use you can think of. When the Kruger design and engineer team starts building an optical instrument, PRO makes the prototype lenses and prisms. When they go to production, Kruger owns the assembly facility in China which uses PRO glass. Kruger has ownership of the whole process. While some of the process is in China, Kruger still owns it all. They use the terms “Crafted in the USA” or “Engineered in the USA”. That will not be good enough for some, but that is what it is too. Kruger also builds things for other companies. One binocular they build is the Cabela’s Alpha Extreme. They also build one of the Cabela’s Pine Ridge binoculars as well.
The Caldera got a pretty decent workout alongside the Razor HD, the ZEN ED 2, and the Promaster ELX ED, and moist recently the Steiner Predator Xtreme. There are a couple of things that immediately stand out with the Caldera. First it is a very short binocular, at 5,25 inches, no longer than a 32 mm compact. I would not say it is particularly compact, but it is enough smaller in size that the difference is obvious. The second thing is the unique ergonomics. It looks like somebody forgot to install the front hinge of a double hinge design. The engineers flatly told me that the hinge is strong enough, as strong as any and any blow that will damage this hinge will damage any binocular. The reason for the no front hinge is to give the pinky fingers a place to go and to give enough room to have the tethered eye cups stay in place. So this gives a different feel than you get from other binoculars. This has built in fold up/down winged eye shields and the rain guard is designed oversized to fit over the folded down wings. Personally, I happen to like the feature, but eye glass wearers may not find it useful. The eye cup wings offer a source of nit pick. They rotate too easily and are never in the same place as they were when you take off the ocular covers. This has a nice, substantial feel, and the construction seems better than some other mid price stuff.
The Caldera comes with fluorite in the objective glass, full broadband coating, and dielectric mirroring. It also has hard, scratch resistant, and substance repellent coatings. It is a very dark charcoal gray/black armored unit with three longitudinal grooves along the side of the binocular. There is a polygonal indentation for the thumbs that is different from anything I have seen.
The case is a zippered clamshell style, similar to what is seen with some Vortex or Zen Ray stuff. They include a patented “cool neck” strap, which is really a pretty good strap. It is light and wide and has an eight inch by two inch zippered compartment. The compartment will hold whatever you wish, but the idea is to use it to hold refreezable cold packs or hot packs. Two hand warmer packs come in the package. They include two QD straps to go on the binocular and the strap snaps into the QD clips. You get two sets of QD release straps. There is no lettering on the strap, so you won't look like a walking Kruger billboard .
This may be just me, but the 438’ FOV seems wider than the specs indicate it is. This was somewhat of a surprise as the ZEN ED has a 426’ FOV. That’s 8.34* for the Caldera and 8.11* for the ZEN ED. I didn’t think that would be a noticeable difference, but to me anyway, it is. It has about the same presence in width as far as "viewing impression" of the ZEN ED 7x36 or even seems very close to my old Swift Nighthawk 8x40 porro which is 9.5* (499'). I’m not sure why this is, or if it will seem so to anyone else, but I sure notice it. On another post here someplace somebody indicated a rolling ball effect with this glass. I saw absolutely no indication of it. There seems to be enough edge pincushion to prevent the effect.
The Caldera focuses counterclockwise to infinity. There is two full turns of focus wheel travel. The close focus is 6 feet. From there to 20 feet takes the same 0.75 turn needed by the Razor HD. From 20 feet to infinity uses another 0.50 turns, leaving 0.75 turns of focus past infinity. The wheel is smooth, with about the right tension and there is no backlash. There is a right eye diopter adjustment on the back of the focus wheel. This one has a small button that is pushed down to unlock the diopter and with the button down, the diopter is adjusted. When done, the mechanism locks when released.
As noted above, the image seems quite wide, giving a big, pleasant view. The image is quite bright, sharp, and has very good contrast. There is a little pincushion at the edge and also some field curvature. The sweet spot is about 70% of the fov. No, the edges are probably not sharp enough for the users who worry about that, but they are as sharp as most binoculars and sharper than many.
I could find no CA or fringing of any kind. This glass handles stray light very well and I found no veiling glare, even panning under the sun or with the setting sun behind me. I got a situation on a recent morning where with a bright, clear sky panning under 7:00 am sunshine over a scenery coated with morning frost where I got some glare right under the sun with the RazorHD. The Caldera handled that glare better than the new Razor. The Caldera is better than the ZEN ED 2 in both areas, and about like the Theron APO-ED.
There is not a lot to separate the image of this and the ZEN ED 2, or the Vortex Talon, and the rest of he class of excellent mid price selections. The Caldera, as well as the ZEN, Promaster, and Theron continue to impress with their optical ability. The Caldera has the edge in a big fov, more compact size, an apparently superior construction, and is the most comfortable for me to hold. The Theron is sharper at the edge, a little brighter, but a smaller fov. The Promaster has a little warmer color bias, but all are pretty good. I had some comparison to the Bushnell Legend Ultra HD as well. The Bushnell is lighter than the rest, has as good centerfield sharpness, but all of the samples I have seen have smaller sweet spot than the others, as well as softer edges. The Bushnell construction strikes me as a little “light”. These are a step down from the new Razor HD, but the differences are still slim.