Zeiss SFL Review | 10×30 & 10×40 | Insanely Good | Best In Class Ultralight Binoculars

When we first considered putting together this Zeiss SFL review, we didn’t really know what to expect. Zeiss Optics has made top notch binoculars, spotting scopes, rifles scopes and more for a long time, and every time a new product emerges, it’s easy to get excited. We wanted to see if they would keep their good reputation with their new Zeiss SFL binoculars, so we put them to the test.

What intrigued me most about the new Zeiss SFL binoculars was where they fit in the Zeiss lineup of binoculars and the gap they seem to fill (at least on paper) in the world of binoculars. They are nearly an alpha class binocular that is super lightweight, compact and perform at an extremely high level. They sit between their mid-range Conquest HD and their Alpha pair, the Zeiss Victory SF. The Zeiss SFL binoculars seem to be the perfect fit for a lightweight, upper end binocular that is a bit more affordable than the true Alpha Class binoculars.

During our massive 26 binocular review, the number of options at the $1,200 – $1,800 price point was very limited, and we noted that without exception, they tended to be heavier and more bulky that your typical 10×42 class binocular. Armed with that information, these Zeiss SFL binoculars were more than just intriguing. We were able to pull some of the binoculars from that review for some side by side testing and comparison against these newcomers.

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

Currently, the Zeiss SLF binoculars come in both a 30mm and 40mm objective with a variety of configurations to cover most applications you may find yourself wanting. You can pick them up in the following configurations:

There is a size for almost every activity you may want to engage in, save for the larger 56mm objective. I bet those will come out before long though.

Let’s dive into how these performed, pros and cons, and what we liked and didn’t like about them.

Love optics? We certainly do here at Backwoods Pursuit, so make sure to check out our MONSTER 26 BINOCULAR REVIEW, as well as our massive 19 SPOTTING SCOPE REVIEW. For both of those reviews, we lined up the optics and tested them side by side!

If you are in the market for some top tier binoculars, make sure to check out our review comparing the Swarovski NL Pure vs Zeiss Victory SF vs Leica Noctivid binoculars. We dive deep into the performance differences of those three pairs of binoculars.

Read 26 Bino Comparison Review

The Specs: Zeiss SFL Binoculars

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

The Zeiss SFL 10×40 binoculars are hands down the lightest and most compact in their class- and it’s not particularly close. At just 22.6 oz for the 40mm version, and an incredible 16.2 oz for the 30mm version, these are in a class all by themselves given their optical performance.

Here are the rest of the specs for the Zeiss SFL binoculars:

WordPress Data Table Plugin

Eye cups: Zeiss SFL Review

One of the areas that we didn’t love about Zeiss Conquest HD binoculars were the eye cups, so we were very interested to see if there were any changes made to these new SFL binoculars. The Conquest HD eye cups are quite comfortable and lock into place nicely, but the eye cups on these SFL binoculars move much more smoothly than the eye cups on the Conquest HD binoculars. Additionally, I don’t see a need to pick up any extensions like you may want to do with the Conquest HD as the eye cups that come with the Zeiss SFL binoculars give you the ability to take full advantage of the impressive 18mm of eye relief.

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

You get 4 positions with these eye cups, all of which lock into place and stay there. There is zero play in the eye cups, no matter which of the 4 positions they’re in. While the eye cups on the Zeiss SFL binoculars are very similar to other Zeiss eye cups, they are definitely an improvement.

Looking for a pair of binoculars? Check out our MASSIVE 26 BINOCULAR REVIEW where we put 26 of the best binoculars side by side!

The edges are thin enough to sink them into your eye sockets if you wish to do that, while still enabling you to retain the full field. Typically, however, if I’m glassing off a tripod I’ll roll the eye cups all the way down as I find that to be my preference.

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

Tripod Adaptability: Zeiss SFL Review

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

The Zeiss SFL binoculars are nicely threaded for a stud, and it is located in what I consider to be the perfect place. The placement allows for maximum stability when using a binocular tripod adapter and gives you the ability to use a number of tripod adapters on the market.

One of the changes from the Conquest binoculars to their newer version is that the SFL binoculars are now a more universal fit, allowing you to use just about any tripod adapter you wish. The picture above shows a side by side comparison. As you can see, the new SFL doesn’t have the rubber armor surrounding the threads, giving more surface area to allow for a wider range of binocular tripod adapters.

I was able to easily use the Swarovski SLC TA, the Outdoorsmans Tripod Adapter, the Bushnell Quick Release Adapter, and of course the Zeiss Tripod Adapter. This was the first time I’ve had the opportunity to test out the Zeiss tripod adapter, and I was pleasantly surprised at just how well-built it is.

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

It’s basically a combination of the Swarovski SLC TA in that you have a similar locking lever, but it also solves one of the primary complaints I have with that particular adapter in that it does not lock, so if that lever gets pushed to the “open” position, your binoculars will slide off the adapter. The Zeiss adapter has that lever AND a locking button that must be pushed to release the optics, making sure the only time your binoculars come off the adapter is when you intend for them to. After using it a few times, this Zeiss tripod adapter quickly became one of my favorites.

Check out Our Video Review of these 4 Great Tripod Adapters

We’ve tested a number of other tripod adapters as well, so take a look at our comprehensive binocular tripod adapter review for additional options!

Focus Mechanism: Zeiss SFL Review

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

During this Zeiss SFL review we paid close attention to the focus mechanism. Based on prior experience, we had high hopes for this new binocular given our overwhelming positive experience with the focus system on the Zeiss Conquest HD and Zeiss Victory SF. The “SF” in both the “Victory SF” and “SFL” stands for “Smart Focus.” But what is “Smart Focus?”

The Zeiss Smart Focus system was designed to provide you with quick and precise focusing, all while still maintaining that silky smooth motion that allows you to easily fine tune your binoculars on the object you are observing without the excessive movement that can take you off target, or add vibration that inhibits your ability to tell if you are truly in focus. The Smart Focus system allows you to focus from 10 feet to infinity in just 1.4 revolutions. This makes focusing fast, easy, and reliable. Bringing objects into fine focus is natural and doesn’t require a lot of the back and forth you’ve likely experienced.

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

The Smart Focus system is also double bridged and very ergonomic for your hand placement on the binoculars. It’s stable, smooth, and consistent. We have yet to find a focus system we like more than the Zeiss Smart Focus system. It’s that good!

Diopter Adjustment: Zeiss SFL Review

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

When we did our testing for this Zeiss SFL review, one of the big questions we had was how the diopter was going to function. If you recall from our Zeiss Conquest HD review, the diopter was an area that we didn’t care for due to how freely it moved. While this might seem like a small thing, it can be a huge frustration to pull your binoculars out of your harness and locate the animal you are trying to observe, only to find that the diopter moved while in your bino harness.

I’m elated to report that this issue was fixed in the new Zeiss SFL binoculars as the diopter is very stiff and offers plenty of resistance to make sure it won’t move unintentionally. While I still prefer a locking diopter, which these SFLs do not have, this is a massive improvement and one I am more than comfortable with. Not everyone wants a locking diopter, so I understand the tension binocular manufactures are trying to manage depending on personal preference.

Feel/Rubber Armor: Zeiss SFL Binoculars Review

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

The Zeiss SFL binoculars are protected by a rubber armor that has a smooth, but non-slip feel to it. This is the same rubber armor you have come to recognize in all Zeiss binoculars. The hinge offers plenty of resistance and stays in place nicely when adjusted to your interpupilary distance. Again, the ease in which a binocular hinge moves can be a source of frustration in the field if it moves too easily while in your harness, but the Zeiss SFL binoculars hit this out of the park. They stay where you left them making getting on target fast and efficient.

Field of View: Zeiss SFL Binoculars Review

During our testing for this Zeiss SFL review we came to love the large field of view that both the SFL 10×40 and 10×30 models provide. The 345 feet @1000 yards for the 10×40 and 360 feet @1000 yards is a generous field of view and above “average” for a 10×42 class binocular. 360 feet @1000 yards is impressive for the SF 10x30s, particularly given the compact size. While the field of view specs won’t blow you out of the water, the generous field of view combined with the clarity, low light performance, and particularly the edge-to-edge clarity, will.

Eye Box Forgiveness: Zeiss SFL Binoculars Review

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

One of the signature features of these Zeiss SFL binoculars is how forgiving the eye box is. By “forgiving” I mean that they give you a fair amount of “cushion” concerning the placement of your face/eyes in relation to the eye cups in order to get a full and complete field of view without having those annoying black spots. In this regard, the Zeiss SFL binoculars offer one of the most forgiving eye boxes on the market today. Because of this, the viewing experience is remarkable because you aren’t in a constant fight trying to avoid black spots as you move across hillsides glassing for animals.

Eye box forgiveness is something not often talked about in terms of binocular features, but when a binocular’s eye box is not forgiving, you notice. A perfect example of this is the Swarovski NL Pure. These are some of the most impressive binoculars we’ve ever tested at Backwoods Pursuit, and are the top performers in our review. Personally, I’ve been using them for a couple of years now, and they are fantastic. However, their eye box is not very forgiving, which can be frustrating at times when they move slightly out of the “sweet spot” in the eye box making you fight black spots in the field of view.

Edge-to-Edge Clarity: Zeiss SFL Binoculars Review

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

Another area we thoroughly tested for this Zeiss SFL review is their edge-to-edge clarity. This is one of the defining features in quality optics, and the SFL binoculars excel. Edge-to-edge clarity is down right impressive, with only the very outer 5-6% of the field of view showing any noticeable loss of clarity. For a binocular giving you so much in the size, weight, clarity, and low light performance departments, it’s impressive that edge to edge clarity isn’t sacrificed.

Low Light Performance: Zeiss SFL Binoculars Review

Given how well the Zeiss SFL binoculars passed each of the tests thus far, we figured we’d have to give up performance somewhere, and typically that is in low light. We found that the SFL binoculars were nothing but impressive in low light as well, but could have been a touch better. More on how they compare to the top performer from our big binocular review below.

The Zeiss SFL allowed us to clearly see well into the twilight hours and much past legal shooting light with incredible clarity and color contrast. While they aren’t the best we’ve tested in low light, they are fantastic and allow you to comfortably glass during the early dawn and dusk hours when it counts most.

Eye Strain: Zeiss SFL Binoculars Review

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

Personally, eye strain is a big deal to me in optics. It’s something that I notice almost instantly when testing binoculars if it’s present. Maybe that’s because I wear contacts, and I’m not getting any younger (You know you’re in trouble when the eye doctor says, “At your age….”), but eye strain is something that really stands out to me. I can say with confidence that the Zeiss SFL are phenomenal in this department. They are the kind of binoculars that your eyes just melt into and you can glass for a long time with ease. That’s what I like and need in a binocular, and the SFL binoculars accomplish that.

Side By Side Testing: Zeiss SFL Binoculars Review

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

It’s easy to pull up a new pair of binoculars and be impressed, but the real test is to put them next to a pair of binoculars that you’ve already tested and know perform well. That’s exactly what we did for this Zeiss SFL review in order to find out how really good they are….or aren’t.

As you can see in the pictures, we tested these out during dreary overcast nights, bright sunny days while glassing snow covered mountains, and into the twilight hours alongside one of our top optical performers, the Vortex Razor UHD from our huge binocular review. We also put them next to the top overall performers, the Swarovski NL Pure because, well, why not?

Zeiss SFL Binoculars vs Swarovski NL Pure

One of the incredible things about the Zeiss SFL binoculars is just how lightweight and compact they are, which is overwhelmingly evident when put next to the Vortex Razor UHDs. It is even abundantly obvious when we put the SFL 10x30s next to the NL Pure 10x32s as shown in the picture above. That aside, the optical performance is really what we were the most interested in. We knew from our testing that the Vortex Razor UHDs were exceptional in low light, as well as edge-to-edge clarity, so if the Zeiss SFL held their own, it would make picking them a no-brainer because of the size and weight savings- a whopping 10 ounces lighter.

Similarly, if they were even CLOSE to the NL Pure, these things would be an incredible value for roughly half the price of the NL Pure. So, how did they perform?

SFL 10×30 vs. NL PURE 10×32

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

First, let’s look at how the Zeiss SFL10x30 binoculars performed next to the NL Pure 10x32s. It might seem ridiculous to put these side by side given the enormous price difference, but I’m sure glad that we did. As expected, the NL Pures were far superior in field of view (360 feet @1000 yards vs. 396ft @1000 yards), but were only slightly better in edge-to-edge clarity. There wasn’t nearly as much difference as I expected, and surprisingly the Zeiss SFL truly held its own in edge-to-edge clarity.

As mentioned above, the Zeiss SFL is far more forgiving in the eye box, which makes them much more pleasant and less finicky to use. However, to my amazement, I found that the Zeiss 10×30 SFL out performed the Swarovski NL Pure 10×32 in low light. I was utterly blown away by as this was completely unexpected. Pair that with the smaller size and lighter weight (22.8 oz vs. 16.2 oz) and it is an accomplishment. Now, I say this as a HUGE fan of the NL Pure, so I didn’t come to that conclusion lightly.

I also found that I slightly preferred the color more in the Zeiss SFL which was another huge surprise during our testing.

SFL 10×40 vs. NL PURE 10×42

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

As amazing as the performance of the Zeiss SFL 10x30s was, I was honestly even more interested in how the 10x40s compared to both the Vortex Razor UHD 10×42 and the NL Pure in the 10×42 variety. The Swarovski NL Pure earned the top spot in our huge bino review, and I’ve personally been using them in the field ever since, so you could say I’m fan. With that said, they are on the heavy side, and the eye box is not very forgiving which are both areas that the Zeiss SFL excels in.

As with the 30mm size, the NL Pure offers better edge-to-edge clarity which is no surprise there. What was surprising was how close it was. The Zeiss SFL 10×40 binoculars were not just excellent in edge-to-edge clarity, they were exceptional. Not QUITE to the NL Pure level, but close. In low light, the NL Pure definitely performed better than the Zeiss SFL, but I was still incredibly impressed with how long the SFL hung in there with the NL Pure; well past sunset and into hours beyond legal shooting light.

The color contrast and image clarity of the Zeiss SFL was nearly on par with the Swarovski NL Pure which is an incredible feat. They certainly weren’t quite on par with the NL Pure, but it was so close that unless you had them side by side you’d be hard pressed to see a difference.

SFL 10×30 vs. RAZOR UHD 10×42

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

For me, this was the true comparison I was looking for; the top optical performer from our previous review which was the Razor UHD 10×42 next to these exponentially smaller and lighter Zeiss SFL 10×40. How did it play out? For those of us out there testing these, we all preferred the Zeiss SFL 10x40s over the Vortex Razor UHD, all the way until EXTREMELY low light. Up until that time, the SFL clearly had an edge in image clarity and color contrast.

However, as it got REALLY dark, the Apochromatic (APO) lenses took affect which made the Razor UHDs out-perform the Zeiss SFL. It wasn’t overly drastic, but the Razor UHDs offered a noticeably brighter and more crisp image at very last light. Then the question becomes, is the extra 10 ounces and exponentially larger size of the Vortex Razor UHD worth the slightly better low light performance? Only you can answer that for yourself.

Zeiss SFL 10×40 vs 10×30

What I liked: Zeiss SFL Review

Zeiss SFL review: Zeiss SFL binoculars testing: Zeiss 10x40 and Zeiss 10x30 review

You’ve probably guessed by now that we came away from the Zeiss SFL review pretty big fans of these binoculars. There was so much to love about them, we were blown away with their performance and value. Here are the things we loved most about them:

  • Image clarity
  • Edge-to-edge clarity
  • Improved diopter
  • Improved eye cups
  • Incredibly forgiving eye box
  • Smart Focus system
  • Best in class, ultra light weight
  • Extremely compact size
  • Great rubber armor and housing
  • Improved threading for a tripod adapter

The Zeiss SFL binoculars are truly incredible, and the combination of features you get makes them absolutely stand out among the rest.

What i didn’t like: Zeiss SFL Review

The Zeiss SFL binoculars really had only one thing that we felt could have been just a little better, and that was their low light performance. Now, to say that it was a downside seems a bit harsh as they still performed exceptionally well in low light, but they weren’t quite as good as the Vortex Razor UHD. It would have been a clean sweep if they had.

  • Extreme low light performance

Zeiss Optics lifetime Warranty

Zeiss Optics covers the SFL binoculars with their “5 Year No Fault Policy” which is nice to have. However, it is limited to one use per product. Additionally, the binoculars are covered by a “Limited Lifetime Warranty” against defects, etc. so your investment is protected in the event something does happen. The warranty does state the original owner must register the product and it has to be purchased from an authorized Zeiss dealer. It is fully transferable, which is also nice. This isn’t the best warranty we’ve seen, but it certainly covers you if something unfortunate does happen to your optics.

Conclusion: Zeiss SFL Review

After doing the testing for the Zeiss SFL review, we walked out not only impressed, but so impressed that I would recommend these binoculars without hesitation, unless you can step up to the Alpha glass category to get a little more low light performance, but you’ll also pay nearly double the money. With that in mind, it’s almost a no-brainer to pick up the Zeiss SFL, particularly if you are looking to shave some weight from your pack.

The combination of size, weight, optical performance, and eye box forgiveness is truly a work of art. I believe these will take over as a fan favorite to replace the no longer made Swarovski SLC, which was a go-to binocular for so many hunters because of their size and weight. Now understand that we’ve had the privilege of testing many binoculars over the years, so we’ve been spoiled and have a lot of knowledge to help compare different ones. To say that I wasn’t expecting to be this impressed with these would be an understatement.

If Alpha Class binoculars are not quite in the budget for you, but you still want top tier performance, the Zeiss SFL binoculars deserve a good hard look. They’ll do pretty much everything most of us need when on a hunt or pursuing the backwoods.

Subscribe to Backwoods Pursuit to get Your FREE Backcountry Gear Worksheet!!!

Dial in your gear list, calculate your pack weight, and lighten up your pack with this handy tool!

Leave a Comment