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Binoviewer eyepieces - a comparison
The eyepiece pairs:
7mm (70 degree) Nikon Fieldscope 60x Wide adapted 1.25 inch
10.5mm (67 degree) Orion Megavista (discontinued)
14mm (82 degree) Meade original-styled Ultra Wide Angle (discontinued)
24.5mm (61 degree) Meade original-styled Super Wide Angle (discontinued)
The telescope model:
Brandon 94 f/6.8 APO
The binoviewer model:
Baader/Zeiss, straight thru mode, unamplified
The observing conditions:
A rural town (pop. 6000) neighborhood under excellent transparent night skies with moonlight.
Test Object #1 -- Full Moon
The 24.5mm was simply excellent! Very sharp, clear, low in color error and nicely comfortable to utilize the entire field. A pair of 18mm (same SWA series) was also compared and found as even better yet with the moon and this scope!
The 14mm was surprisingly excellent, too, and gave a tremendous viewing impression. Very sharp, clear, low in color error and quite comfortable to view the entire field. The moon was panned from one side of the field to the other to verify this last issue.
The 10.5mm was very good overall. Very good sharpness, clarity, slightly excessive color error noted, and good comfort to view the entire field.
The 7mm was very good overall with very good to excellent sharpness. Clarity and color correction were excellent to superb. Same with the resulting level of contrast. Comfort was good to very good to view the entire field.
Test Object #2 -- Sword of Orion
The 24.5mm was again excellent and provided good levels of that "wow feeling" within the view. This was more umph than a 61 degree afov would suggest. It is a result partly associated with the long eye relief and flat field of the design. There was some image distortion (star stretching) when the eyes moved slightly side to side off center-axis. When viewing from center-axis, outboard bright stars at the ends of the sword asterism were still pleasingly sharp.
The 14mm gave tremendous results. After having experimented with many different telescope eyepiece pairs in the past, nothing this good was anticipated. The "wow feeling" was very evident and strong. It was almost too exciting as a result as the whole 82 degree afov was quite easy to take in and utilize comfortably. The original game plan was to look carefully and objectively for this as a potential outcome.
There was a small tendency noted in the 14mm for image blackout. The defect presented itself only as a minor fluttering effect when the eyes panned the stationary viewing field. This came across as non-problematic and enough above a critical threshold to call the result "very good". It was much easier to observe in comfort than was found using many other wide or extreme fielded eyepieces. This was simply amazing and fun to determine! The 14mm Meade seems to handily beat out (strictly based on the main optical criteria) pairs of 11mm Naglers, 12mm Nagler Type 2's, 12mm (80 degree) Speers-Walers, 14mm (68 degree) Leicas, 15.5mm (75 degree) Meade Research Grade Erfles, and 16mm (80 degree) University Optics WideScans.
The 10.5mm gave a close in view of the Orion Nebula. Image was sharp and contrasty. The full field was acceptably comfortable and useful to work with.
The 7mm also gave this "close in" perspective, and contrast was now balanced to an excellent level. This considering a bright full moon in the sky. Field was sharp to the edge and quite easy to sweep with the eye.
Test Object #3 -- The Pleiades
The 24.5mm framed this beautiful cluster very well. The star stretching distortion, produced during lateral misplacement of the eyes, was scrutinized using this object. Result was of acceptability, but not by a good comfortable margin. The viewing quality still remained high and the overall eyepiece performance seemed quite pleasing.
The 14mm allowed for minimal-sized (still good) framing of this object. The view was excellent with a very acceptable level of eyes-in-the-field sweeping comfort.
And... in conclusion:
All four pairs of eyepieces performed very well used in a good binocular viewer.
Overlooking its bulkier weight, the 14mm Meade Ultra Wide Angle gave a truly sensational two-eyed performance. This will unlikely be duplicated until new, similar or better models are commercially introduced.