Telescope Reviews: Swarovski 8.5x42 vs Fujinon 7x50

My favorite bino for some time now has been the massively clunky Fujinon FMT-SX 7x50. Bought used for only $300, it provides daytime views that always impress me with clarity, color saturation, resistance to stray light, and comfort. The images give the impression of a great detail just under the threshold of the 7x magnification access, just screaming, if you know what I mean. At night, we here understand the limitations of the 7mm exit pupil, but the star images are extremely tight, star colors are shown well, and the view, provided you're not greedy for detail, is satisfying. In a very dark sky, of course, the 7x50 wakes from the dead.

But there's a new bino in the house, a Swarovski EL 8.5x42, bought for my wife who's an increasingly avid birder, and who has recently seen the light of day through my 7x50, compared to her modest former bino. The FMT, besides being mine, is no binocular for a lady! So a fool and his money....would that be me and mine? Anyhow, $1500 LNIB off Astromart, and oh my is she happy!

This is the first roof prism I've ever used, and I had to see with my own eyes if even one of the best made could equal or beat the famed Fujinon. We are comparing apples and oranges here, you might say, the racing sloop to the tugboat. But anybody who's looked through an FMT knows that optically, this could not be a cakewalk for the high-zoot roof. Many ardent birders have reviewed the EL vs similar Zeiss and Leica, and much has been said and argued in that arena. Next to that crowd, I'm hardly anything like an expert. But rarely do the top roofs and porros meet. They tend to live on different sides of the tracks. Simply being able to lay my hands on both puts me into the unique position, despite my inexperience compared to some here, to address this question which I have long wondered. I'll talk about ergonomics, then optics.

Both have plenty of eye relief for eyeglasses use. While the Fujinon's long, soft rubber eyecups are perfect for non-glasses use, in bright light the EL's eye relief is a tad excessive, resulting in slight blackouts if you snuggle up close and pan your gaze around. Thanks to member "etc." for recommending a higher upward-extending eyecup, which is on order. With the exception of this single issue, ergonomically, the comparison is a no-brainer of the first water, and I'll get this right out of the way. 29 oz for the roof vs 50 for the porro, close focus 7 for the roof vs 25 ft, smooth and properly resistive center focus taking me from infinity to 12 ft in one big finger motion vs individual focus, twist up/down eyecups vs tedious slow folding soft rubber cylinders, side-mounted strap connections so the roof hangs comfortably straight down vs angle inducing bottom connections on the Porro. The roof style is narrow, smooth profiled, and compact. The EL's open-bridge construction beats most roof bino's gripability, in that you can wrap your fingers securely around the tacky rubber armored barrels and confidently one-hand it in a pinch. For the birder, all this would be worth a nice bundle, even if optically you lost a bit going to the roof.

Which, well. You don't. In fact, you might even gain a tiny bit, depending on your taste. I am not making this up, Porro heads. The view is essentially the same knockout as that in the Fujinon, just 63 degrees wide instead of 53 degrees, and 8.5x instead of 7x. All differences are down to really nitpicking details. The EL's view is just as bright, just as apparently sharp and color rich. It just as well-shielded against bright light just outside the field of view. The Swaro's field is somewhat flatter, and sharper at the edge on an equidistant scene, but with a bit of astigmatism/coma that could not be focused out at the edge, instead of the Fujinon's almost pure field curvature. (The Swaro's field correction and edge sharpness does not quite equal the 10x50 Fujinon, not a subject of comparison here, but a standard of excellence in this regard.) Color cast is not a big deal to me, but is to many birders. If I point the Fujinon at a white field I see a very faint yellow-green (My 7x50 is the older model with the simple green coatings, the new coatings are better.) The Swarovski shows only pure white(The coatings on the Swarovski look excellent--dark and multicolored, similar to the new-style Fujinons). At the center of the field, with the eye centered behind the eyepiece, I can't see any lateral color in either, even under the most extreme contrast conditions, but, off center, it's there, to the same degree in both, which is moderate, given the normal-glass optics.

At night, the Swarovski's star images are tight and excellent. This is a very important thing to me, and the two binos aren't quite the same, if you really look close. The FMT's stars are just a tiny bit fatter, likely because they contain a bit more light (at 57 yrs, my pupils still open 6.5mm, enabling me to put 46mm of the Fujinon's objectives to use). While bright stars in the Swarovski look at first, tighter, they have, on close inspection and to a very tiny degree, a faint surrounding haze. This is such a weak effect that I, double-star lover that I am, have a hard time choosing which I prefer. But the difference is there--The FMT makes larger light spots which are, however, more cleanly contained. As you'd expect from the above discussion of the field, the Swarovski's wider apparent field and better edge correction is impressive. Across star fields whose size was measured on a good star chart, Swaro has a true field of 7.5 deg (vs 7.4 claimed) while the Fuj actually shows 7.3 deg (vs 7.5 claimed). The sky background looks darker in the 8.5x42, due to the smaller exit pupil I suppose, which is sort of pretty in a way, but more importantly, enables the 8.5x to show, to my eye, just as faint a star, with the same difficulty, as the larger 7x. As far as detail shown, the magnification advantage of 8.5x over 7x supercedes the light-gathering advantage of the effective-46mm 7x, and more is shown in celestial objects, both in revealing lunar crater detail, and in open cluster untangling ability.

Finally, I felt obliged to perform a measurement, something ought to be objective after all. I used a 7x loupe with a 0.1mm scale to measure the exit pupil of the Swaro at 4.95 +or- 0.05mm, vs 4.94 calculated from the specification, and used the loupe to look at a scale laid across the objective imaged in the exit pupil, and could see 41mm +or- 1mm. So, as near as I can measure, the specification 8.5x42 is correct. Such is also the case for the 7x50.

I don't really know if you have to spend quite THIS much to get this kind of performance in a roof. Probably not. I'm basically a tightwad, when it comes to my own stuff. This, however, was not for me, and I wanted to be sure she had the best. DO NOT try one of these, you'll be sorry. It is amazing but true, and I will shout it from the rooftops: the best roof is as good, optically, as the best porro.
Ron