The Zeiss FL range is Zeiss\\\'s latest attempt to conquer the premium binocular market. Priced at the top end of the market, it is intended to compete head to head with offerings from Leica, Nikon and Swarovski. The 7x42, 8x42 and 10x42, FL continue the Zeiss tradition of using Abbe-Koenig prisms with higher transmission than the more usual Schmidt-Pechan prisms. Another unusual feature, and the origin of the FL name, is the use of triplet objectives with an element of fluoride glass. Zeiss claims that this significantly reduces colour fringing. The optics are of course fully multi-coated (T*) and the prisms are phase coated (P*).
Build and Design
The Zeiss 8x42 FL has a typical roof prism binocular shape consisting of two parallel optical assemblies connected by a central hinge. The optical assemblies are tapered, being broader at the objective end and, unlike many competing instruments, do not have thumb indents. The binocular is almost entirely covered in black rubber armour with a matt texture: it is high quality and very pleasant to the touch.
The large rubber armoured focus wheel is situated between and slightly in front of the eyepieces. It can be accessed from above, in the normal manner, or held between thumb and forefinger for making fine adjustments. The wheel turns smoothly with no perceptible backlash or stiffness, and is highly geared for a rapid focus. The high gearing might trouble some people, though I found that I soon got used to it, and appreciated the speed with which I could lock on to a bird.
The dioptre adjustment is achieved by pulling out the focus wheel, then turning until the required setting is achieved. Zeiss claim an adjustment range of +/- 4 dioptres. There\\\'s not a lot to say except that it works.
The eye tubes screw in and screw out and have four positions including two intermediate ones. The eye tubes are, like much of the internal structure, made from a composite material. For comfort the ends are covered with rubber. They work well.
It is worth noting that the strap lugs are well placed, since a common criticism of the original Victory range was that the strap lugs dug in to the sides of the hands.
Weighing in at 755g the binocular is one of the lightest in its class.
The binocular is waterproof and filled with nitrogen to prevent internal fogging.
According to Zeiss the internals are made from a combination of metal and a composite described as fibre-reinforced polyamide. Although some people might question the use of plastics (or, as Zeiss might say, advanced polymers), there\\\'s no doubt that it provides strength whilst keeping weight to a minimum. The only negative aspect, in my opinion, is the central hinge covering, which seems to be made from high-density polyethylene, and to my eyes it looks slightly cheap in contrast to the rest of the instrument.
The binocular is supplied with a very good neoprene strap, a rain guard for the eyepieces, excellent removable objective caps and a very good holster case with strap. The presence of a strap on the case is a welcome change from the norm.
The binocular provides a superb image, which in many ways, but not all, surpasses any other binocular I have tried. The field of view is class leading at 135m at a distance of 1km. On axis, sharpness and contrast are excellent and even with my eyeglasses on the image has that \\\"with your own eyes\\\" feel characteristic of the best optics.
On-axis colour fringing is absent. There is a trace of off-axis chromatic aberration in high contrast situations but it is negligible and probably will not even be noticed by many users.
There is a trace of pincushion distortion at the edges of the field, sometimes noticeable when panning, but it is not significant, and I do not notice it in normal use.
There is some off-axis softness which starts to appear at about 60% from the axis, and gradually increases until the edge where the image is mediocre. This is perhaps the only (minor) weakness in the optics. Although re-focussing can recover some sharpness, most of the softness is from aberrations other than field curvature.
Flare is, as with most if not all premium binoculars, extremely well controlled, and was not a problem. Ghosting was not seen. I saw no obvious colour cast, though I am very poor at seeing a colour cast.
Eye relief, which is of particular importance to eyeglass wearers, is generous at 17mm, and I found that I could view the whole field of view while wearing eyeglasses. (Eyeglass wearers should check for themselves, as there are wide variations in eyeglass frames and individual facial features. I have small frames that sit close to my eyes, and I do not have sunken eyes, all of which help with viewing through a binocular.)
Comparison with other instruments
I own a Zeiss 8x42 FL, a Nikon 8x32 SE and a Swarovski 8.5x42 EL and was able to do some side by side comparisons.
The Swarovski 8.5x42 is quite rightly a best seller, with superb ergonomics and build quality, and excellent, but not in my opinion class leading, optics. It has slightly higher resolution than the Zeiss, consistent with the higher magnification and it has slightly better off-axis sharpness. However, it has slightly lower contrast, and in high contrast situations noticeable chromatic aberration, even on axis. In my highly subjective opinion the Zeiss provides an overall image that is one step above the Swarovski, though the Swarovski is nevertheless a fine instrument. Of course some people might disagree with my conclusions.
The Nikon 8x32 SE is in my opinion one of the finest 8x glasses in existence. It has superb sharpness and contrast, roughly on a par with the Zeiss. However, the Nikon also has almost no distortion, almost edge-to-edge sharpness, and an almost completely flat field. There is some chromatic aberration, both on and off axis, in high contrast situations, though it is minor, and can usually be ignored. The Nikon has in many respects slightly better optics than the Zeiss, but it is not waterproof, the image is not as bright in low light, the on-axis image is not quite as good, the folding rubber eye tubes are less convenient and the small focus wheel can be rather stiff in cold weather. Overall the Nikon is a superb instrument and at about half the price of the Zeiss it is a bargain, albeit one that is less rugged and convenient. However, as discussions on Bird Forumhave shown, the SE is surprisingly rugged, and if treated with a little care, should last many years without any problems.
Overall I think that Zeiss have done an exceptional job. The use of fluoride glass is a definite innovation in premium birding binoculars and does exactly what Zeiss claim: in my opinion the one problem with most roof prism binoculars is excessive chromatic aberration, and in the FL Zeiss have overcome this issue. I was pleasantly surprised at the high contrast and the excellent sharpness. I was less impressed with the off-axis sharpness, which though very good, does not match that of the best competing instruments. The Zeiss FL has excellent ergonomics and I found little to fault. The armour is good quality, and has a pleasingly soft texture. The eye tubes, with intermediate positions are a welcome innovation. The smooth backlash free focus wheel is extremely well placed, and easy to use. Some might consider the focus too coarse, but the high gearing allows rapid acquisition of fast moving objects, whilst the smoothness and absence of backlash allow for fine adjustment. The binocular is waterproof and I can testify to this fact having on numerous occasions been caught in torrential rain. In many respects Zeiss have borrowed the best features of other instruments, and then added a few of their own (triplet objectives, multi-position eye tubes). I have already heard that one other manufacturer has introduced a roof prism binocular with triplet objectives. I suspect they will not be the last.
If you are looking for a premium waterproof binocular, and have the cash, then I reckon that you should take a look at the Zeiss FL range.
Comment added 28 March 2005:
After using a Zeiss 8x42 FL for 6 months, I remain as impressed as ever with the optics. Compared side by side, colours through my Nikon 8x32 SE seem slightly but noticeably subdued, whilst colours through the FL have more clarity and vibrancy, due no doubt to the better colour correction. Combined with the high contrast the result is an incredibly natural and bright image. The slight distortion is, for me anyway, a non issue. The slight off-axis softening is sometimes noticeable when birding, but is a minor irritation rather than a flaw. It is however more obvious when using the binocular on the night sky, presumably because the eye is more likely to explore the field when viewing stars. In terms of ergonomics, I have become more accustomed to the fast but sensitive focus, and would not go back to a slower version.