Zeiss SFL Binocular
Review

Filling a gap in the world of high-end binoculars

Zeiss SFL 10x40

A birder was telling us about her old binoculars the other day. A binocular she'd been happy with when she bought it. The optics were excellent. The binocular offered all she asked for in resolution and brightness.

"But it's just so... so big," she said. "I love to look through it, but I don't always love to carry it."

Immediately we thought about the new Zeiss SFL, which is going to be available this year, in 2022. Zeiss recently gave us an advance look at the 8x40 SFL.

I knew what she meant about "so big." Sometimes birders want something a little smaller.

Finding the sweet spot

So many things to consider! Optical quality. Carryable weight. Exit pupil. Manageable length. Field of view. Hand friendliness. And of course economy. So let's consider the SFL in the light of these considerations.


OPTICAL QUALITY ~ When we tested the SFL against high-end 42mm and 32mm binoculars, we found they all had excellent optical quality. All provided stunningly bright, sharp, clear images.

The biggest differences between these binoculars show up in the weight, exit pupil, length, field of view, and price.


Zeiss SFL

WEIGHT ~ The Zeiss SFL 8x40 binocular weighs 22.6 ounces. Close to the weight of a high-end 8x32 binocular.

The SFL feels light. You notice this immediately when you pick up the binoculars and even more when using them for an extended time. 

Weight of ZEISS SFL 8x40 compared to 32mm binoculars
MODEL Zeiss
SFL 8x40
Zeiss
SF 8x32
Swarovski
NL Pure 8x32
Weight 22.6 oz 21.2 oz 22.8 oz


Weight of ZEISS SFL 8x40 compared to 42mm binoculars
MODEL Zeis
SFL 8x40
Zeiss
  SF 8x42  
Swarovski
     NL Pure 8x42
Swarovski
EL 8.5x42
Leica
Noctivid 8x42
Vortex UHD
Razor 8x42 
Weight 22.6 oz 27.5 oz 29.5 oz 29.5 oz  27.9 oz 32.2 oz 

The SFL is much lighter than the above high-end 42mm binoculars now on the market.



EXIT PUPIL ~ To calculate the exit pupil, divide the size of the objective lens by the magnification. The result is the size of the exit pupil, in millimeters. That is the size of the column of light coming through the binocular.

When a binocular has an exit pupil with a larger diameter, that makes it easier to get the binocular in front of the pupils of your eye. This is why many birders find it easier to use a 42mm binocular than a 32mm or 25mm model.

In very dim light of dusk and dawn, a larger exit pupil may also provide a brighter image to some users.

The Zeiss SFL 8x40 has an exit pupil much closer to that of a full-sized, 42mm binocular than to any 8x32 binocular. As a result, when we compared it against 32mm binoculars, we found that the SFL very comfortable to look through and quick to get positioned each time we raised it to our eyes.

Exit pupil ZEISS SFL 8x40 compared to 42mm binoculars
MODEL Zeis
SFL 8x40
Zeiss
   SF 8x42   
Swarovski
NL Pure 8x42
Swarovski
 EL 8.5x42 
Leica
Noctivid 8x42
Vortex UHD
Razor 8x42 
Exit Pupil 5 mm 5.25 mm 5.25 mm 4.94 oz 5.25 mm 5.25 mm


Exit pupil of ZEISS SFL 8x40 compared to 32mm binoculars
MODEL Zeiss
SFL 8x40
Zeiss
SF 8x32
Swarovski
NL Pure 8x32
Exit Pupil 5 mm 4 mm 4 mm


LENGTH ~ The Zeiss SFL 8x40 is compact and feels comfortable on your chest. It's actually shorter than the high-end 32mm binoculars we compared it to. This is one of the great advantages of the new SFL.

It also fits nicely in the hand.  Check the photo at the top of the page. Also notice how easily the index finger reaches the focus knob.

Length of ZEISS SFL 8x40 compared to 32mm binoculars
MODEL Zeiss
SFL 8x40
Zeiss
SF 8x32
Swarovski
NL Pure 8x32
Length 5.1 in. 5.9 in. 5.7 in.

Most high-end 42mm binoculars are longer than the SFL by an inch or more. The SFL is comfortable on your chest.

Length of ZEISS SFL 8x40 compared to 42mm binoculars
MODEL Zeiss
SFL 8x40
Zeiss
   SF 8x42   
Swarovski
 Pure 8x42 
Swarovski
 EL 8.5x42 
Leica
Noctivid 8x42
Vortex UHD
Razor 8x42 
Length 5.1 in. 6.8 in. 6.2 in. 6.3 in. 5.9 in. 7.0 in.


FIELD OF VIEW ~ The Zeiss SFL 8x40 has a field of view of 420 feet at 1000 yards. It matches the Vortex Razor UHD and very handily outcompetes the Leica Noctivid.

Although the field of view is not so generous as the top-line Zeiss SF and Swarovski NL Pure binoculars, the SFL costs a lot less. (See the price chart, below.)

Field of View of ZEISS SFL 8x40 compared to other binoculars
MODEL Zeiss
SFL 8x40
Zeiss
   SF 8x42   
Swarovski
 Pure 8x42 
Swarovski
 EL 8.5x42 
Leica
Noctivid 8x42
Vortex UHD
Razor 8x42 
Field of View 420 ft. 444 ft. 477 ft. 399 ft. 405 ft. 420 ft.


CLOSE FOCUS ~ It's nice to be able to look at a hummingbird at the feeder without having to back away from your window. The chart shows the minimum focus distance in feet. The SFL focuses plenty close enough for hummingbirds.

Close focus of ZEISS SFL 8x40 compared to other binoculars
MODEL Zeiss
SFL 8x40
Zeiss
   SF 8x42   
Swarovski
 Pure 8x42 
Swarovski
 EL 8.5x42 
Leica
Noctivid 8x42
Vortex UHD
Razor 8x42 
Close Focus 4.9 ft. 5.0 ft. 6.6 ft. 10.8 ft. 4.9 ft. 4.5 ft.


PRICE ~ The Zeiss SFL is at an interesting price point. You get a top-quality binocular at an affordable price. 

Price of ZEISS SFL 8x40 compared to other high-end binoculars
MODEL Zeiss
SFL 8x40
Zeiss
   SF 8x42   
Swarovski
 Pure 8x42 
Swarovski
 EL 8.5x42 
Leica
Noctivid 8x42
Vortex UHD
Razor 8x42 
Price $1800 $2999 $2999 $2199 $2849 $1650


THE SWEET SPOT ~ It seems that Zeiss has landed in a sweet spot with the new SFL binocular. High quality optics. The right size. Comfortable to carry and look through. We think birders will love it.


The 10x40 SFL

Zeiss SFL

The new Zeiss SFL binocular is made in two sizes, 8x40 and 10x40. The 10x40 has the same size, weight, and price as the 8x40.

The differences are of course the magnification, which is 10-power in the 10x40, the field of view (345 feet), and the exit pupil (4 millimeters).

Both models are for sale in the Birdwatching Dot Com Store. Supplies will be limited for a while, as Zeiss revs up their production schedule to fill the demand for this new binocular. 

Zeiss SFL 8x40
Zeiss SFL 10x40 

Review of new Zess SFL 8x30