Oberwerk 15x70 or Pentax 16x60
Posted 22 July 2004 - 01:40 PM
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Posted 23 July 2004 - 11:00 AM
My search for handholdable binoculars for both day and night use has led me to try a variety of binos including 7x50, 10x50, 9x63, 11x56, 15x70 & 16x70. Those represent both the lower and upper ends of power and size for serious handheld binocular astronomy. 60 and 63mm obj. binoculars offer a very interesting merger of features that make them ideal candidates for astronomy and long range terrestial viewing. They offer better light gathering than anything in the 50mm class, and are generally lighter weight and more handholdable than anything in the 70mm category. 15-16x power offers the astronomer something that lower power units simply can't show. That's the ability to see Mag 11 stars. Until fairly recently, though, folks wanting an affordable 60mm bino had very few to choose from. Swift has offered a 15x60 that some long range birders enjoy, but for whatever reason that model hasn't caught on with amatuer astronomers. Presently, the situation is changing and several companies including Pentax, Oberwerk and Orion are offering binos in the 15-16x60-63mm class.
After seeing Barry Simon's review of the Pentax version of the 16x60 concept, where he compared them favorably to the legendary Fujinon FMT-SX 16x70's, I decided to try a pair.
(That review is available both on Cloudy Nights and on Yahoo Groups bino-net.) The Fujinons have been the defacto reference standard for large astro binos for years, but given that they weigh over 5lbs with included hard case and accessories and are individual eye focus, they're not at all suited to normal handheld terrestial use. Given that the Pentax have had lots of praise from various hunting organizations, I very much hoped that they'd bridge the gap between 10x50's and 16x70's in terms of offering portable, handholdable high magnification.
When I got them, I was immediately convinced that they were in fact very handholdable and were likely just the blend of high power and portability that I'd been wanting. They are considerably smaller and lighter than the Oberwerk 15x70's and look almost like standard sized binos when compared to the giant mass of the Fujinons. They are a full 1.8" shorter than the Oberwerks, which in turn are smaller than the Fujis. The Pentax 16x60's could be shoulder carried on a hike without too much hassle, whereas the 70mm binos really are too big for much of that. That is the primary reason that I wanted a set of them. In that aspect they do in fact live up to the idea of a portable high power bino.
I was very pleasantly surprised by the overall exterior quality of them. They came in a nice soft vinyl case and had a camera-quality neck strap. Fit and finish are surprisingly good considering that they're made in China. They look much more like what we've come to expect from good Japanese makers. Oddly, there was no spec. sheet or instuction sheet with these. And much more of concern, the supplied optics caps aren't captive, but they do fit snuggly. I've spent several days comparing them both in daytime and at night to the Oberwerk 15x70's and the Fujinon FMT-SX 16x70's. I've used all 3 binos both handheld and mounted.
The raw specs for all three of these binos can be found at the manufacturer's and resellers respective websites, but I wanted to touch on many of the major similarities and differences.
Pentax PCF V 16x60's--
Super Multicoating on aspherical lens elements, (NOTE:-- nowhere have I seen the words Fully Multi-coated in company literature about this product.)
Obj. lens 2 elements in 1 group
Ocular lens 4 elements in 3 groups
FOV= 2.8* (This is extremely narrow for this or any type of binocular, more on that in a minute.)
Apparent FOV= 45* or only 49m @ 1000m
Eye relief= 20mm
Close focus= 26' (I'd say more like 30')
Ht. & Width= 8.5"x 7.5"
Weight= 42.7oz (NOTE: this is only 10.2 oz heavier than the PCF 10x50 and similar 10x50's, but it's 33.3 oz. lighter than the Fuji 16x70's!!)
features a focus lock
MSRP= $370US, but current street prices are $170-$220US
Fit, finish and accessories, -- better than Oberwerk, but not up to Fujinon
Overall the ergonomics of the Pentax 16x60's are very good, but the oversize popup plastic eyecups make it uncomfortable for those of us with wide nose brigdes. Glasses wearers won't notice this. I'd thought that this was due to having oversized occular lenses, but upon measuring them, I found that the reverse is true. The Pentax actually have the smallest available occular surface of the 3 binos. The Pentax have 20mm of clear eyepiece, while the Oberwerks have 21mm and the Fujis have 24mm of clear occular.
Also, these binos may be somewhat difficult for those with widely spaced eyes to merge images in. I'm not positive, but I think the issue is where the occulars are mated in respect to the prisms. This is likely not a major problem for most users, but I'd HIGHLY recomend trying a pair of these prior to buying them. The other aspect of the oversize plastic eyecups is that they're significantly more uncomfortable when laying back in a lawn chair than are the standard rubber eyecups. Overall, I'm not a fan of this style eyecup.
I was very surprised to see that the Pentax showed almost equal dark sky contrast to that of the Fujinons. The difference between the high contrast Pentax and the lower contrast Oberwerks was substantial.
FLARE CONTROL, CHROMATIC ABERATION AND GHOSTING--
Equally surprising was the downright terrible view of Jupiter that the Pentax gave. I was really expecting much better than the mushy view that I got, and the Pentax showed multiple ghost images of the giant planet. The Oberwerk did MUCH better. On Saturn , both the Oberwerks and Fujinons clearly showed the rings, but in the Pentax the impression was just of an oblong. Perhaps most disturbing to me was the amount of purple fringing that the Fujinons showed. Ever since I really started looking for it, I've been seeing more and more purple coloring in the outer 50% of the Fujinon's FOV. The only time I notice it is on Jupiter or the Moon. Other than that I'm very happy with the view in the Fujis and they basically don't flare or ghost. The fact that the Pentaxes did flare, ghost and mush as much as they did was really quite off-putting, but I did not notice this on any other celestial objects. They show stars as pinpoints. In daytime use, the Pentax show very good color rendition and separation.
As Barry previously reported, the Pentax are very good in this regard. It's almost hard to see any real image deterioration before the very outer 3mm. The Fujinons are reknowned for having very good edge performance, but even they don't do significantly better.
The 2.8* FOV of the Pentax is just barely enough to squeeze the 3 Orion belt stars into. Really, going below 4* FOV in a binocular begs the question of why? These things aren't the best tool for scanning the Milky Way, but I did find that with practice I could track a satellite in them despite the extremely narrow field.
I taped a multicolored supermarket flyer to a box a measured 50yds away from our picnic table and tried out all three binos from a table mount. The Oberwerks could resolve 10mm type at 50yds, but tended to have trouble distinguishing light colors. The Pentax could resolve 5mm type and showed very good color separation and rendition. The Fujinons resolved 3mm type and had by far the best color definition. The terrestial views through the Fujinons are really very, very good. It's too bad that they're so big and bulky that terrestial use is basically out of the question.
DEPTH OF FIELD--
The Pentax show very little depth. The Oberwerks are slightly better in this aspect, but the Fujis are even a good bit better. This is not something astronomer's need worry about, but it's worth pointing out that the Pentax can't really just be locked on infinity for best terrestial use. They must be precisely focused at each different distance.
Forget it. The 3.8mm exit pupil of the 16x60 Pentax makes them dim out considerably earlier than many mid-size binos. They're able to discern detail and colors longer than the Oberwerks, but no where near as long as the Fujinons. It somewhat surprises me that these are marketed to big game hunters. I suppose they're pretty good for their configuration, but that's an instance where I'd trade magnification for twilight performance every time.
Aside from the disappointing views of Jupiter and Saturn, and the narrow FOV, I very much enjoyed the good contrast views of the nightsky with the Pentax. The views of the Pleaides, M42, the nose of the bull in Taurus, and M35 were spectacular . M41 was resolved so well that it really didn't look like much beyond just individual stars.
In daytime usage, the 16x60's showed details on a red-tailed hawk that were not to found in the Leupold 10x50's despite hard looking.
I think that the Pentax 16x60's are worth a look for anybody in the market for a large handholdable binocular. They don't get everything right, but they do get a lot of things right. It's worth pointing out that both Oberwerk and Orion offer a selection of binos in the 56-63 range with far wider FOV's at attractive prices. The Oberwerks are only around $110 and the Orions are made in Japan. It'd be very interesting to compare the Pentaxes to the offerings by those companies. Overall, I like the Pentax 16x60's and think that they represent a solid value as well as an interesting option, despite their few shortcomings.
(ed. note, the spacing of this post was changed 12-05-01 but NO content was altered)
(This message was last edited by Light Trap at 11:51 AM, Dec 6th, 2001)