With the introduction of other big optics, this Kowa TSN 99 review was something that we really wanted to put together. How does this Kowa TSN 99 spotting scope stack up against the uber popular Kowa TSN 88 spotting scope? We had the luxury of putting these two side by side to see the difference for ourselves. There are limited options in the large spotting scope market, which is primarily occupied by the likes of the Swarovski ATX 95 mm and the newer 115 mm objective, along with the Zeiss Victory Harpia 95 mm spotting scope.
Check out our MASSIVE SPOTTING SCOPE REVIEW where we lined up 19 of the best spotting scopes we could find and put them to the test. All side by side with volunteer testers, no brand loyalties (at least as much as humanly possible), varied lighting conditions, and 14 guys ranking these things. What an awesome project to put together! This review is a product of over two years of work, research, and testing. You don’t want to miss this!
Dive into the details on every one of the spotting scopes in the review above by becoming a Backwoods Pursuit Member (TOTALLY FREE) and you can download the data we used to put together this review.
Kowa: Premium Optics
Kowa Optics has been a quickly growing favorite in the hunting community over the last several years and for very good reason. Bird watchers and nature observers have long been keen on the Kowa Optics spotting scopes, but for whatever reason, they had not gained the same traction in the hunting community until recently. As more and more folks have the opportunity to compare the Kowa spotting scopes to others on the market, the results are speaking for themselves.
What makes Kowa spotting scopes stand out from the crowd? In addition to their incredible optical performance, they are available at a more reasonable price point than some other top tier glass. While Kowa Optics are by no means budget optics, the value is some of the highest you are going to find. The combination of extremely high value and absolute top notch performance make Kowa spotting scopes an easy sell. Affording them still is not easy though.
Now, when we are talking specifically about the Kowa TSN 99 series of spotting scopes, they take the game to a new level. While many have touted the Kowa TSN 88 as one of, if not the best, spotting scope money can buy, you would think the Kowa TSN 99 can only improve on that performance…..or can it? To get a better feel for just how different the Kowa TSN 99 and TSN 88 were, we put them side by side to see for ourselves.
The Testing: Kowa TSN 99 Review
During the testing for this Kowa TSN 99 review we were able to use the Kowa TSN 99 spotting scope throughout the hunting season, as well as multiple comparison opportunities next to the Kowa TSN 88, Tract Toric UHD, and new Athlon Cronus UHD Gen 2. Obviously, all of these feature a smaller objective lens, and the Tract Toric UHD and Athlon Cronus UHD are in an entirely different class and price point, but it is always fun to put them side by side and see the real world differences.
Check out our review of the Athlon Cronus UHD Gen 2, as well as our review of the Tract Toric UHD Spotting Scope to see where each of them shine and where they fall short.
Looking for a binoculars? Check out our MASSIVE 26 BINOCULAR REVIEW where we put 26 of the best binoculars side by side!
We used the Kowa TSN 99 for digiscoping to film our review of the THROOM targets as well as tested it with the Kowa 1.6x Extender which changes this setup from a 30-70×99 mm into an incredible 48-112×99 mm spotting scope. How realistically usable was that setup? We’ll find out.
The Specs: Kowa TSN 99 Review
The Kowa TSN 99 Spotting scope is not just impressive optically but its specs will surprise you as well. Like the other Kowa TSN spotting scopes, you get Kowa’s legendary dual focus system, which has become our favorite spotting scope focus system of any that we have tested to date. Here are the physical specs of the Kowa TSN 99 spotting scope:
| Kowa TSN 99 Specs | ||||
|---|---|---|---|---|
| Magnification | 30-70x | |||
| Objective Size | 99 mm | |||
| Field of View @ 1000 yds | 60 ft – 105 ft | |||
| Eyepiece Angle | 45° | |||
| Weight | 77 oz | |||
| Eye Relief | 17 mm | |||
| Body Material | 100% Magnesium Alloy | |||
| Dimensions | 15.5″ x 3.5″ | |||
| Glass | Fluorite Crystal + Kowa XD Lens | |||
| Tripod Attachment | Yes – Threaded | |||
| Country of Origin | Japan | |||
| Current Price | $3,999 | |||
The Kowa TSN 99 is the lightest in the “BIG GLASS” category, and if you are carrying an especially large spotting scope around on a hunt, this is the one you want as far as weight goes. As you can guess, it is also quite large and not the type of spotting scope you are typically going to carry around in your backpack but that is not why you would typically purchase this spotting scope anyway. Consequently, I don’t mind a couple extra ounces vs the competition in this spotting scope category. These are what we consider “truck spotters” or spotting scopes you take when you have a stout tripod and a vehicle to carry them in.
Because of the size, weight, and extra 10x magnification you get with this Kowa TSN 99, this is a spotting scope you want if you spend a lot of time glassing, have a really good tripod to set it on, and plan to cover a lot of country from a place where you can drive some kind of vehicle to.
Pure Fluorite Glass: Kowa TSN 99 Review
So, why does it matter that Kowa uses a pure fluorite crystal lens? This lens is generally considered to produce the best image you can get in today’s optics. Pure fluorite crystal lenses virtually eliminate chromatic aberration while providing highly contrasted images with exceptional resolution.
Pure fluorite is much more difficult to handle than typical optical glass, so it is much more expensive to produce optics featuring pure fluorite lenses and is why it is used less frequently. The optical performance difference is clear though.
The Eyepiece: Kowa TSN 99 Review
The TSN 99 series spotters also feature minor, but positive, updates to the eye piece. The biggest change is that the new eyepiece offers much more resistance to changing positions which helps keep it from shifting while riding in your pack. The other benefit we found in this new design is that it handles digiscoping with your phone much better as it will hold your phone in place for those landscape shots if you need to roll the eyecup out a click or two.
Another small change is in the lettering that indicates the magnification for the TSN 99 series of spotting scopes. The TSN 99 uses the same eyepiece as the TSN 77 and TSN 88 series spotting scopes, so all the new eyepieces have a secondary set of numbers that apply only to the TSN 99 series (see more detailed description below regarding the difference in magnification ranges).
The Kowa Optics Prominar TE-11wz 25-60x Wide Zoom eyepiece is very comfortable, functioned well, and provided a very pleasant viewing experience. The eyepiece also has a rubber coating that adds durability and is pleasant to the touch.
We found the zoom mechanism to have the perfect amount of resistance. Not so stiff that it moves the optic when you want to zoom in on an object but not so loose that it rotates unintentionally. The mechanism was very smooth and there was zero play.
Another thing we noticed in the Kowa TSN 99 spotting scope was just how forgiving the eye box was. While this is a less talked about topic, its a big deal when glassing for longer periods of time. It was especially noticeable when put next to the Athlon Cronus UHD Gen 2 spotting scope that we were testing. The Kowa TSN series of spotting scopes are more pleasant and more forgiving to look through than many other options on the market.
Magnification Range & Exit Pupil – 30-70x: Kowa TSN 99 Review
One of the unique things we found through this Kowa TSN 99 review is that it offers a greater magnification range than most spotting scopes. The Kowa Prominar TE-11WZ Wide Angle Eyepiece that is used across the Kowa TSN series of spotting scopes generally produces a 25-60x magnification range; however, while that is very functional in its own right, that same eyepiece on the TSN 99 delivers an incredible 30-70x magnification range. I was not sure how usable that extra 10x would be, but to my delight, it is not only usable but superb.
When put next to the Kowa TSN 88, I found that the TSN 88 set at 60x ever so slightly outperformed the TSN 99 at 70x in low light. It may go without saying, but simplistically, all optics will typically perform worse with higher magnification. Fortunately, that can be offset to some degree with a larger objective, but it all comes down to the exit pupil size (an indicator of how bright the image will be under low light conditions).
To demonstrate how the exit pupil is affected by the combination of objective size and magnification, let’s take a look at the calculation: Exit Pupil = Objective size / magnification:
- TSN 99 – Minimum Zoom: = 99 mm / 30x = 3.30 mm exit pupil
- TSN 99 – Maximum Zoom: =99 mm / 70x = 1.41 mm exit pupil
- TSN 88 – Maximum Zoom: = 88 mm / 60x = 1.47 mm exit pupil
As you can see, when you are maximum magnification, that exit pupil size shrinks to less than half of what it is at minimum magnification, so less light can be gathered for the image. Now, for fun, we compared the exit pupil of the TSN 99 @ 70x vs the TSN 88 @ 60x, and as you can see, our visual results were confirmed as the Kowa TSN 88 SLIGHTLY outperformed the TSN 99 in low light. The exit pupil is 0.06 mm bigger with the TSN 88, giving it ever so slightly better light gathering ability under that scenario.
Now, if you add in the Kowa 1.6x Extender, those exit pupils get REALLY small as you increase the magnification:
- TSN 99 – Minimum Zoom: = 99 mm / 48x = 2.06 mm exit pupil
- TSN 99 – Maximum Zoom: =99 mm / 112x = 0.88 mm exit pupil
- TSN 88 – Maximum Zoom: = 88 mm / 96x = 0.92 mm exit pupil
With the extender installed, atmospheric conditions and light quickly become the limiting factors as heat waves are magnified, particularly at higher magnifications. You also lose a bit of resolution, but surprisingly, not as much as you may think. The image is still very good with the extender mounted. If you opt to use the extender, you will want to have a very substantial tripod as any vibration will render the optic virtually useless. This is also a limitation under even minimally windy conditions. We found the Athlon Midas tripods to work exceptionally well for these larger spotting scopes.
Dual Focus System: Kowa TSN 99 Review
One of the trademark features of the Kowa TSN 99 spotting scope, and all Kowa spotting scopes, is their very popular dual focus system. This focus system has proven time and again to be a fan favorite in our testing, and our testers all love the functionality and design. It especially stands out when attempting to focus on small details as the smaller fine focus wheel combined with the perfect amount of resistance reduces vibration considerably compared to the barrel focus systems that most spotting scopes offer.
This really shows itself when trying to fine focus on objects a long ways off, particularly if you are using a tripod that is on the lighter side (i.e., one you might take hunting). In our testing for this Kowa TSN 99 review, this dual focus system was hands down better at bring objects into fine focus over any barrel focus system, no matter the brand. Even the most fluid barrel focus system was no match.
The dual focus system of the Kowa TSN 99 Spotting Scope is exceptionally smooth and easy to fine tune. It gives you the perfect resistance that avoids moving the optic when focusing, but we did notice a little bit of play in the larger coarse focus wheel. This has been observed in all of the Kowa TSN spotting scopes, and getting rid of that play would be my top suggested improvement on the Kowa TSN series of spotters.
I have been using these Kowa TSN spotting scopes for years now. The play in the coarse focus wheel is non-issue for all functional purposes, but given the price point and how amazingly well everything else functions, the focus wheel play is a bummer. That said, I RARELY use the coarse focus wheel, so it is not something that stands out during most field use.
Weight & Body Construction – Kowa TSN 99 Review
The body of the Kowa TSN 99 spotting scope is made up of 100% magnesium alloy, making it extremely durable while not adding extra weight. Unfortunately, Kowa spotting scopes do not have a rubber armor, which is one of the common complaints I hear about Kowa spotting scopes. While I share that disappointment, it is not a big enough issue to cause me to shy away from a Kowa spotting scope. While that rubber armor is nice to the touch and protects the housing, it also adds weight and the Kowa TSN 99 is already on the heavy side as it is.
Image Clarity/Low Light Performance – Kowa TSN 99 Review
While a digiscoping photo with a phone never seems to do that actual image quality justice, the above is a picture of a bedded buck I spotted at over 2,000 yards away. I forgot my digiscoping adapter on this trip, so please forgive the poor alignment of the image. I did my best to hold my phone up to the spotter, but as you can see, the image is crystal clear and made it easy to determine that this was not just a deer but a smaller buck.
Once the spotting scope was set up and focused, we could also see a few ears of other deer (does) just to the left of the buck. We would have been hard pressed to get to him before dark given the terrain between us, but in this case, the high quality Kowa spotting scope allowed us to determine from distance that this was not quite the buck we were looking for and saved us a lot of climbing that may have been necessary to get closer otherwise.
During this Kowa TSN 99 review we tested its low light performance next to its smaller brother, the Kowa TSN 88. We knew from our previous testing that the Kowa TSN 88 was as good as it gets when it comes to low light, so if the TSN 99 was better, it would further extend the usable glassing time and could make a huge difference during the twilight hours when big bucks and bulls tend to move the most.
While not surprised, per se, we were extremely impressed by the low light performance of the Kowa TSN 99 spotting scope. Even though the smaller Kowa TSN 88 is absolutely incredible in low light, the larger objective of the TSN 99 lets even more light in and provided a brighter, more usable image later into the evening while on comparable power. While saying it provided better image resolution than the Kowa TSN 88 would be a stretch, the image was certainly brighter.
Edge-to-Edge Clarity – Kowa TSN 99 Review
Just like the TSN 88 the Kowa TSN 99 provides nearly flawless edge-to-edge clarity. This is one of the hallmark features of the highest quality optics, and throughout this Kowa TSN 99 review, we were nothing but impressed. There is zero compromise throughout the entire field of view, and this is impressive given that it is a wide angle eyepiece with a massive field of view.
Chromatic Aberration – Kowa TSN 99 Review
Chromatic aberration is something that most optics other than the very best suffer from. To varying degrees, you can often pick out that fuzzy/hazy/color-distorted edge on a tree branch, rock shelf, or antler tip at longer distances, especially toward the edge of your field of view. However, the Kowa TSN 99 virtually eliminates chromatic aberration. When detail matters most, and particularly at long distances, chromatic aberration can be a killer. That where the Kowa TSN 99 spotting scope excels and provides you with as crisp of an image as we have tested to date.
Field of View – Kowa TSN 99 Review
Throughout this Kowa TSN 99 spotting scope review, we were absolutely impressed with the combination of incredible clarity and massive field of view. With as many spotting scope as we have tested, believe me when I say that this is rare. Optics are a game of tradeoffs, and typically, you are forced to give something up to get a huge field of view. Often times, you find that the wide angle lens will give you a “fish bowl” feel with the edges appearing curved. Or you lose that wide field of view in exchange for fantastic edge-to-edge clarity. Other times you give up some magnification to maintain that flat field of view and/or great edge-to-edge clarity.
At the end of the day, this Kowa TSN 99 review showed us that it is possible to have it all when it comes to optical performance. However, one limitation we found is that when you have a minimum magnification of 30x, it can make finding your target quickly a bit more challenging at short to mid-range distances. We had the Kowa TSN 773/88 next to this Kowa TSN 99 and the TSN 773/88’s lower minimum magnification of 25x proved easier to acquire a deer that we had spotted at about 700 yards.
For comparison, it is worth highlighting the field of view specs of the Kowa TSN 99 Spotting Scope vs other spotting scopes we have tested:
- Kowa TSN 99 (30-70x): 60 ft – 105 ft
- Kowa TSN 773/883 (25-60x): 76 ft-138 ft
- Athlon Cronus (20-60x): 60 ft-117 ft
- Leupold Santium SX-5 (27-55x): 73 ft-105 ft
- Meopta Meostar WA (30-60x): 68.8 ft-146 ft
- Maven S1A (27-55x): 83.3 ft-115.2 ft
- Sig Oscar8 (27-55x): 73 ft-105 ft
- Swarovski ATX 85 (25-60x): 68 ft-124 ft
- Tract Toric UHD (27-55x): 73 ft – 105 ft
Now, keep in mind that each of these have slightly different low and high magnifications. Generally, the lower the magnification, the bigger the field of view, and the higher the magnification, the smaller the field of view gets.
What We liked: Kowa TSN 99 Review
This Kowa TSN 99 review left us nothing but impressed. Its optical performance is second to none that we have tested, the dual focus system is our overall favorite of all the spotting scopes we have reviewed, and the 30-70x magnification range is incredible. The fact that 70x is not only usable but performs at nearly the same level as the Kowa TSN 88 at 60x is extremely impressive in itself.
We loved the extremely forgiving eye box of this spotting scope which made longer glassing sessions a breeze. We also loved the build quality, smooth zoom mechanism, low light performance, and exceptional value relative to its performance.
Kowa TSN 99 highlights are summarized below (there is a lot to like!):
- Massive field of view
- Incredible 30-70x magnification
- Near perfect edge-to-edge clarity
- Flat field of view
- Image resolution
- Low light performance
- Smooth zoom mechanism
- Dual focus
- Build quality
- Excellent warranty
- Great value
What We Didn’t Like: Kowa TSN 99 Review
After testing for this Kowa TSN 99 review, there was very little that we came away not liking. However, there were a few small things that we would like to see improved. First, the slight play in the coarse focus wheel is disappointing given that this is what we consider to be an “Alpha Glass” optic.
Additionally, with a weight of 77 oz (with lens covers), the Kowa TSN 99 isn’t the lightest in class that we are accustomed to from Kowa. For example, the Zeiss Victory Harpia 95 mm comes in at 79.8 oz, so slightly more, but the Swarovski ATX 95 mm comes in at 75.2 oz. Surprisingly, this makes the Kowa TSN 99 heavier than the ATX, whereas the Kowa TSN 88 is one of the lightest in its class. I supposed this isn’t entirely out of line given that the Swarovski ATX features a 95 mm objective, whereas the Kowa TSN 99 features a larger 99 mm objective lens.
At the end of the day, the things we didn’t love about the Kowa TSN 99 mm spotting scope were:
- Play in coarse focus wheel
- Weight (77 oz)
See How the TSN 99 and TSN 88 Are Different!
Kowa Lifetime Warranty
Kowa Optics offers a lifetime warranty that is transferable. I have not needed to test out the warranty but it is good to know that your purchase is backed by (what I hear to be) a solid warranty. Make sure to register your purchase with Kowa to be eligible for warranty coverage.
How The Kowa TSN 99 Spotting Scope Ranked
Image Clarity
Low Light Performance
Weight
Chromatic Aberration
Edge to Edge Clarity
Overall Value
Conclusion – Kowa TSN 99 Review
This Kowa TSN 99 review showed us just how much optical performance can be obtained in a spotting scope and how far the limits can be stretched. The Kowa TSN 99 spotting scope performance is top notch in all areas and will not leave you wishing for more. Sure, the price tag is up there and it is something you will have to save for, but it is a great value compared to the cost of similarly performing spotting scopes.
If you need elite performance and do not mind the size and weight penalty, the Kowa TSN 99 is one of the best “Big Glass” options available on the market today. If you can fit this spotter into your budget, you will not be disappointed.
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