CN FORUMS ARCHIVE Telescope Reviews: First impressions

First off, let me assure you that I have quite limited experience with binos. Although I feel I’ve learned quite a bit regarding optical quality on telescopes and eyepieces over the past year, I still consider myself a little wet behind the ears when using both eyes. That said, I have attempted to use the basic mechanical, optical, and ergonomic points of binocular testing to guide me in this very basic, and early, assessment.

Upon first impression, this pair of 8x40 WPII’s seems well built. The finish on the outside of the casing is consistent with the rest of the PCF WP line – rugged and slip resistant, with a nice flat black appearance.

A close inspection of the coatings on both the objective and eyepiece lenses shows a deep purple and green, when held at an angle against the sunlight. In a well lit room, without direct lighting , no facial details can be seen while looking at my own reflection. Shining a flashlight against the objective lens produces three reflections, first two are green and magenta, third is a very slight pale bluish-white. When shone against the EP lenses the result is six reflections, magenta, green, blue-green, pale green, pale blue-green, and pale bluish-white.

Glancing down the barrel, from the objective side, no prisms are noted to obstruct the light path. And from the EP end, when held about 8-10 inches away, the exit pupil appears perfectly round.

Inter-pupilary distance ranged from 57-75mm across the adjustment range.

The EP’s move only slightly, and only with stern grasping on my part.

The heavier weight of 28oz., for this size bino, felt well grounded in my hands, resisting too much jiggle on star points. Additionally, the design of the barrels allowed my hands to find a comfortable position without any thought at all. My wife agreed with this point, stating how easy they were to hold.

The center focuser was moderately stiff, yet smooth and easy to operate. It was also within easy reach of both index fingers (I have medium sized hands) to allow quick adjustments in both directions. The right diopter adjustment was notably stiffer, although I don’t see this to be a problem, as this tends to be a “set and forget” adjustment.

On center sharpness was very good, although not as nice as the Swaravoski spotting scope that I looked through at my local shop. If the Swarovski was a 10 out of 10, then the Pentax easily came in at 8. Still better than my Father-in-law’s Minolta 7x35 Classic rating a 7, or my brother’s Bushnell 7-15x35 which is possibly a 6 at the 7x end of the zoom scale. I also performed a modified “dollar bill” test. Since I seldom have cash on me (with my wife and daughters always mere steps behind me) I chose a Coke can. At 25 feet, the dietary info was clear as a bell. In fact, I learned at that point that a can of Coke has 50grams of sodium. Shikies! That a lot of salt.

When testing for sharpness across the field I used several test subjects, including stop signs, street signs, stars, and white framed windows on a Victorian house approximately ½ mile away. In all instances the field maintained a consistent sharp focus about 80% of the way from center. The next 5%, although not as sharp was still acceptable, and the remaining 15% was fuzz or worse. When tested on stars, of dimmer than 1.0 magnitude, pinpoint focus was possible. But with brighter objects (stars and planets), transverse spherical aberration was noted, splaying rays out like a small spider (and not so small on Venus). Longitudinal spherical aberration (seagulls?) was noted 80% out and beyond.

Some slight yellow-green color fringing was noted in daylight against high contrast signs. But I also noted this in the Swarovski spotting scope, albeit to a lesser degree, so I have decided not to fret over it.

Some mild pincushion distortion was noted on distant buildings when pushed to the edge of the field. Although scanning my back field for wildlife yesterday did not produce a nauseating sensation. Of course, I can read while driving so I may not be the best judge here.

Although I did not do specific measurements on TFOV, the Pleiades appeared approximately less than 1/3 the diameter of the field, lending me no reason to doubt the manufacturer’s measurement of 6.3 deg. M45 was quite stunning BTW, crystal clear and well framed.

Overall, I would certainly recommend these to any one looking for this size bino, not looking to spend more than $200. They appear to be of good construction, and good optical quality. Views were consistently clean and sharp, as if I could reach out and touch my viewing subjects. At one point my Yellow Lab took a sprint in the back field (probably chasing a stray oak leaf) and tracking him was quite easy. And from 100 feet off I could still make out the individual hairs on the back of his neck. I don't regret this purchase, and impatiently wait for the work week to end so I can have more time behind them.

Clear skies,
Chopin

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Jason®

VeritableImagery

Reflectors: 110/900mm, 250/1140mm (in progress)
Refractors: 80/400mm, 72/430mm ED
Binoculars: 8x40mm, 15x85mm
Eyepieces: Televue Naglers, Faworski Abbe orthos
Canon 1D, 20D, 10-24mm, 50mm, 70-200mm, 150-500mm