Until WWII, the standard size for compact binoculars was the 6x30, and it was part of the equipment of the armed forces all over Europe. Later on, this part took over the 8x30 binocular, perhaps a consequence of the gradually improving surface coatings which increased the light transmission and hence compensated for the reduced low-light performance of the higher magnification. On the civilian market the 8x30 Porro was also quickly established as a handy instrument for traveling and remained so until about the 1970s, when it was more and more replaced with the compact and better sealed binoculars of roof-prism type.
Running against the wind, Nikon had the courage to develop a new line of high end binoculars of Porro-prism type for civilian use, the 'SE' line, consisting of the 8x32, 10x42 and 12x50 models. This review is investigating the performance of the smallest of them, and comparing it with two currently issued military glasses of 8x30 specification.
Fig. 1: The Nikon 8x32 SE
The Nikon Superior E ('SE') is of traditional Porro I prism design, but of modern construction using magnesium alloy for the body, lead/arsenic free glasses and a synthetic rubber armoring. There is a durable rubber protection around the objectives. The eye-cups can be down-folded for use with eye glasses. This binocular has got a convenient central focuser, but it is not waterproof. Its optical quality however has already reached an almost legendary reputation. On Stephen Ingaham's birding page 'Better View Desired' the Nikon 8x32 SE defines the reference standard (i.e. product so outstanding that it sets the performance standard for its class) not only for mid-sized binoculars but also as overall best birding binocular - despite of the fact that for most birders the use of one of the high end roof-prism binoculars seems to be little less than a status symbol. Of course, the price for this glass is high enough to underline its high end position: With a list price of around 970 $, and an actual retail price of about 600 $, it is anything else but cheap, but still of significant lower price than the top class roof prisms.
Fig. 2: The Fujinon 8x30 FMTR-SX
The Fujinon 8x30 FMTR-SX was first of all developed for military use, but, like the item to be tested, also available without gimmicks like reticle and laser protection filters. This binocular is currently employed by the Japanese Self-Defense Army and the Finnish armed forces, among others. As usual for military glasses, it has got individually focusing oculars, a robust rubber armor and it satisfies the US military specifications for water- and mechanical impact resistance. The FMTR-SX has got oculars with an additional field flattening lens to reduce distortion, and it is coated using a patented electron-beam technique to ensure an improved light transmission. The eye-cups can be folded down for use with spectacles on. Apparently, the objectives are air spaced, indicating a rather sophisticated optical construction. The list price for this item is 710 $, but I have seen it off-sale on US Internet sites for as little as 350 $.
Fig. 3: The Hensoldt 8x30 Fero-D 16
The Fero-D 16 is one member of Hensoldt's latest line of binoculars, which also contains a 7x50 (Fero-D 18) and 10x50 (Fero-D 19). They seem to be exclusively produced for military use and come with a reticle and additional built-in filters against laser light of 1064 nm wavelength, i.e. within infrared range. 'Fero-D' is the short form of 'Fernrohr-Doppelt', meaning 'double-telescope'. The Fero-D 16 was introduced to the Bundeswehr around 1990 and at that time it replaced the Steiner 8x30 Fero-D 12, which was in service since the early 1070s and which had itself replaced the old Hensoldt DF of the 1950s. It is of roughly the same size and weight as the DF, but shows the characteristic 'bent shoulder' and is nitrogen purged to prevent internal fogging. This new version has got a longer eye-relief but a reduced field of view. The individually focusing oculars are equipped with down-foldable rubber eye-cups for spectacle wearers. I don't know of any official retailers, but the Fero-D 16 is sometimes found on E-bay in used but good condition and sells for about 300 Euro.
Fig. 4: The Nikon SE, Fujinon FMTR-SX, Hensoldt Fero-D 16
The following table summarizes some of the specifications of the contenders.
|Real angle||Apparent angle||Eye relief||Exit pupil||Weight|
| ||of view (deg)||of view (deg)||(mm)||diam. (mm)||(kg)|
|Nikon 8x32 SE||7.5||60||17||4.0||0.65|
|Fujinon 8x30 FMTR-SX||7.5||60||16.6||3.8||0.75|
|Hensoldt 8x30 Fero-D 16||7||56||14.5||3.8||0.65|
Image sharpness: These binoculars are of such a quality that only the outer parts of the field display some weakness. In fact, both the Nikon and the Fujinon appear almost sharp to the edge during day time observations. More selective is the star test. From center to about 85% (radial) toward the edge both, the Fujinon as well as the Nikon, show stars which appear point-like and sharp. At the outermost edge, the aberrations still remain on a moderate level. Both instruments show a very similar signature here, and I was unable to discern any significant difference. It appears that the close to edge sharpness of the Fujinon 8x30 is a little bit lower than in the Fujinon 10x50 FMTR-SX. The Hensoldt shows a reasonable 70% of clean field with increasing aberrations beyond that, and close to the edge they reach a moderate to high level. This is somewhat disappointing, when recalling the performance of the old DF, which also came with point-like stars within 70% of the field, but had a significantly larger angle. Simply stopped down to 7 degs., its close-to-edge performance certainly had been better than what is offered by the new Fero-D 16.
Image color: The Nikon and Fujinon are absolutely neutral and come both with an unusually bright image. The Hensoldt displays a slight but visible green tint. I speculate that this is caused by the laser protection filters. Although supposed to be active in the infrared, they are perhaps also cutting off a small amount of the visible red part of the spectrum, so that the passing residual light becomes greenish. Despite of that, the contrast of the image is quite good and clearly superior to the old DF.
Rectilinear distortion: The Fujinon is almost free of distortion. Consequently, the still image preserves horizontal or vertical lines almost to the outer parts of the field, whereas the moving image displays the characteristic globe effect, i.e. the image seems to roll over a semi-sphere when panning. The Nikon employs a slight pincushion distortion to compensate for this effect, and the scrolling of its image is very smooth and without any apparent residual motion. The Hensoldt has got a slightly larger pincushion distortion and seems to over-correct the rolling ball: Close to the center of the field, the objects seem to move away, an effect which can also be observed with the NVA's 7x40 EDF.
Stray light: Under difficult viewing conditions, especially at twilight, light from sources outside the field can enter the objective lenses through a large angle to illuminate the tube walls and is, partially, scattered into the optical path. The prevention of this diffuse stray light is mandatory to maintain a high contrast under such conditions and is masterly done in the Hensoldt. There was hardly any trace of flare visible even if a bright object was located just outside the field. The Nikon and Fujinon are also well protected against stray light. I was able to produce a dim, diffuse and concentric ring of light close to the edges in some situations, but the intensity of this effect remained low and did not affect the image contrast within the central region of the field. Here the Fujinon 8x30 performs better than its 10x50 brother.
Ghost images: If, at night, a bright object (street lantern, moon) is positioned into the field, reflections on the air-to-glass surfaces take place, which can lead to multiple 'ghost' images of the light source. The Nikon shows a most impressive performance here. Even strong light sources were unable to produce any visible reflections. I haven't seen any binocular yet with this degree of immunization against secondary images. The Fujinon, however, is not far behind. There are a couple of needle-fine and rather dim spots produced inside the oculars. It seems that this 8x30 glass is a bit more prone to ghosting than the 10x50 model. It may as well be the case that the demo-glass which I have got was somewhat older than the 10x50 and that the surface coating has been optimized since then. Anyway, the resistance against reflections is still on such a high level that ghost images are not going to pose any problems even when bright objects like the moon are observed. The Hensoldt shows a few diffuse spots of low-to-moderate intensity. It is performing better than the older DF, especially on the right hand side where the light has to pass the reticle. Still it doesn't reach the spectacular level of suppression as set by its competitors. One has to keep in mind that, with its laser filters and reticle, the Fero-D 16 has got some extra glass surfaces which could cause trouble, and a civilian version of this binocular were likely to perform better here.
Low light performance: The exit pupils of 3.75mm and 4mm do not suggest these binoculars to be used excessively under low light conditions. At least, the Nikon and Fujinon make the best of it. With their impressively bright images they perform quite well even under low light conditions. There were few situations in which a slightest difference of the Nikon's and Fujinon's performance could be made visible. In these cases, however, the Nikon consistently was a little better. This was e.g. the case when observing the galaxy M51 which was (under the sub-optimum viewing conditions near to the city of Karlsruhe) just at the limit of visibility through the Fujinon and came with a slightly better contrast in the Nikon. This could easily be the result of the little larger objective size of the Nikon SE: 32mm vs. 30mm provides the extra 14% of light which could have made the difference. The Hensoldt delivers an image of visibly less brightness, although the contrast still remains high. Its greenish tint is not of advantage under low light conditions. It is well known that after sunset the spectrum of the residual light is shifting towards blue. A warm tint of the binocular then helps to compensate for this effect by shifting the light-mixture back towards the direction where the eyes are optimized for. That's why binoculars with a slight yellow tint appear to perform especially well after sunset. Again, without the laser protection filters the Hensoldt were likely to work a little better here.
The 'final score' is the sum of the individual scores and is intended to serve as an orientation only.
This competition has got two winners, and their optical performance sometimes seemed to be so close that, if they hadn't shown opposite distortion characteristics, one could have suspected them to be produced at the same factory. The most characteristic features of the Nikon SE and the Fujinon FMTR-SX are their unusually bright image and excellent sharpness almost up to the edges of their fields, which are of exactly identical size with 60 degs. It requires patience and maybe a little bit of hair-splitting to find the optics of the Nikon to be slightly superior to the Fujinon's. This is the case when it comes to the prevention of ghost images of very bright light sources and in situations of especially low light when the larger size of the Nikon's objectives pays off. The Nikon SE is also more compact than the Fujinon and offers the convenient central focuser. I would therefore declare the Nikon to be my favorite, unless the circumstances of application were likely to become tough and environmental hazards like moisture, dust or very low temperatures were to be expected. In this case, the Fujinon is the better choice. With this item as a companion, the optical performance won't be compromised, but one has to carry a somewhat bulkier piece of glass and has to focus individually. If one needs all at once, hight optical quality, compactness and water resistance, then one should look for one of the high end roof-prism binoculars and has to be prepared to pay a premium.
The Hensoldt Fero-D 16, itself a good binocular, is not fully competitive here. One has to keep in mind that this test was a little bit unfair: Being a full fleshed military device, it is featuring laser protection filters and a reticle and these handicaps could not be compensated for, at least not against a competition like the Nikon's and Fujinon's. One can estimate that 1064nm laser filters absorb about 10% of visible light (thanks to Tilman Taube for that information). Compared to the old Hensoldt 8x30 DF, the new version provides an improved contrast, better ghost image and stray light suppression and it is now purged with nitrogen. For whatever reason, the angle of field has been reduced, without being able to improve the edge sharpness. By doing this, in my opinion, Hensoldt has missed a chance to construct a really excellent binocular. On the positive side, it is compacter than the Fujinon and better sealed than the Nikon. Without its laser filters, this binocular were likely to perform significantly better, that's why I suggest to get rid of them if there is such an opportunity.
Last updated: 2004