Telescope Reviews: Small Binocular Reports The 10x50s

Small Binocular Reports The 10x50s

Fujinon FMT-SX – 10x50, 6.7°, er=13mm, IPD=57-76, close focus 50ft, lens fmc/prisms fmc,
Oberwerk Mariner 10x60 – 10x52, 5.1°, er=21mm, IPD=61-73, cf 50ft, fmc/fmc
Pentax PCF WP - 10x49, 5.0°, er=13mm, IPD=57-74, cf 20ft, fmc/fmc
Leupold Wind River Mesa - 10x48, 5.3°, er=17mm, IPD=58-74, cf=23ft, fmc/fc
Nikon Action Extreme - 10x48, 6.1°, er=13mm, IPD=56-73, cf=20ft, fmc/fc
Nikon Action - 10x46, 6.5°, er=9mm, IPD=56-73, cf=20ft, fmc/fc
Orion Ultraview - 10x46, 6.0°, er=13mm, IPD=59-71, cf=20ft, fmc/fmc
Bushnell Legend - 10x46, 6.4°, er=14mm, IPD=59-72, cf=25ft, fmc/fmc
Garrett Genesis - 10x44, 6.1°, er=16mm, IPD=60-74, cf=25ft, fmc/fmc
Oberwerk 10x50 - 10x43, 6.4°, er=13mm, IPD=58-72, cf=30ft, fmc/fc

The Orion is the lightest at 30oz. (850g.). The Oberwerk is the heaviest at 38oz. (1080g.) The Bushnell is heavy at 37oz (1050g.). The Nikon Action and the Leupold are quite light at 32oz. (900g.). The Oberwerk mariner, not really a 10x50 weighs in at 48oz. (1350g.)

The Pentax has the least pincushion. The Garett and the Oberwerk have the most.

Not all were tested for field curvature. The Nikon Action shows the most curvature, the Leupold and Bushnell the least.

The eye relief is specified as Orion 22mm, Pentax 20mm, and Nikon AE 17mm. In reality, all three, including the Oberwerk have exactly the same, 13mm of usable eye relief, just enough for eyeglasses. The Nikon Action er is too short for eye glasses at 9mm.

The Orion has the least right diopter range. The Bushnell Legend has a right diopter identical to the Orion, but has a greater range of accommodation. The Bushnell diopter grip is extremely difficult to grasp and use and getting the right focus is a challenge. Pentax, Leupold and Nikon Action have twist diopters. The Nikon Action and Leupold right eyepiece height changes with diopter adjustment.

The Nikon AE and the Nikon Action share the widest IPD range 56-73mm. The Oberwerk Mariner has the most difficult for narrow eye people at 61-73 will not accommodate some people, especially children. The Orion has the narrowest IPD range 59-71mmof the 10x50s.

Only the Nikon Action and the Orion Ultraview are NOT waterproof.

Many of these binoculars have a close focus of 20-25ft. (6m to 7.5m). But with slight variation +/-, they all have only 80% of the field of view in binocular vision at 20-25ft. Only one or two binoculars in my test group have more than 80% of the fov overlapped at closest focus, however all the roof prism binocular that have closest focus at about 6-7ft (2m.), when used at a distance of 20ft have approx 90% of the fov in binocular vision.

The Nikon AE baffles stop the aperture down to 48mm. The Pentax, 49mm. The Orion Ultraview is both stopped down and losses 6% of the light to undersized exposed prism edges, it therefore has an effective aperture of only 46mm. The Nikon Action is stopped down by a too small prism aperture. The Bushnell Legend, is stopped down and the front prism intrudes considerably into the light path. Both the Oberwerks, the 10x50 and the Mariner, and the Garrett 10x50s, are considerably stopped down, more than any of the others.

The Nikon Action the Garrett and the Oberwerk share the best normal power resolution. All three measured the same for on-axis resolution, none of them rating very high in this category. The Leupold had the lowest reading for resolution.

Boosting the test power by 6x normal, the Nikon AE and the Nikon Action held up with the best boosted resolution. The Bushnell Legend had by far the worst boosted resolution, one of the worst readings recorded out of 34 binoculars. The Leupold had a very poor boosted resolution. These poor reading are giving some indication of aberrations present in the system.

The Nikon AE lenses are multi-coated, however the prisms appear to be only single coated, preventing that one from being labeled FMC. Yet the Nikon AE see stars equally as faint as the Pentax and both of them see slightly fainter stars than the Orion Ultraview. This gives a good indication that light transmission is dependant on much more than just good coatings.

The Bushnell Legend and the Nikon Action Extreme turned in the best readings for control of internal vignette and light path tilt. The Orion, the Leupold, the Oberwerk 10x50 and the Oberwerk mariner were by far the worst, showing considerable vignette in the prisms and dramatic tilt in the light path.

The Garrett Genesis and the Nikon Action take top score for illumination of the exit pupil. The Leupold, the Oberwerk10x50 and the Oberwerk Mariner have the lowest readings for illumination.

The Leupold has by far the best outer field sharpness, with less than 1 arcmin total distortion all the way out to 90% of the field. Pentax, Oberwerk 10x50, Oberwerk Mariner, then Bushnell and Garrett, in that order have the best marks for field sharpness. The Orion Ultraview and particularly the Nikon Action has the worst outer field sharpness.

The Oberwerk, Leupold and Bushnell have the widest usable fov, all three greater than 4.5° of fov. You might find it interesting that although the Pentax has only a 5° fov, it can see the same stars at 80% out that both the Orion and the Nikon AE can see at no more than 65% out, so all three have an equally sharp 4.0° fov.

Observing
Here are a variety of observations of M78 and M1. All of these are from recent observing sessions with groups of the Small Binoculars.

M78 under mag 5.4-5.5 skies
Fujinon FMT-SX 10x50 picked out M78 immediately as a bright and easy target.
Oberwerk Mariner 10x60 (10x52), seen good, but not bright and not easy.
Leupold WR Mesa 10x50, seen good, but not bright and not easy.
Nikon AE 10x50, seen good, but not bright and not easy.
Garrett Classic 10x50 (10x44) searched, just barely seen, difficult object.
Oberwerk 10x50 (10x43) needed to search, barely seen, difficult object.

M78 under mag 5.2 skies,
Orion Ultraview 10x50 (10x46), barely seen
Pentax PCF WP 10x50, barely seen
Nikon AE 10x50, barely seen
GO Classic 10x50 (10x44), barely seen

M78 under mag 4.9-5.0 skies
Fujinon 10x50, M78 was immediately visible. Central stars are not seen.
Bushnell Legend 10x50 porro, seen Good.
Nikon AE 10x50, not easy but was seen OK.
Nikon Action 10x50, not easy but was seen OK.
Could not find it in any binocular handheld. Saw in Fujinon handheld braced.

M1 under mag 5.2 skies
Several 10x50s, Orion Ultraview, Pentax PCF WP, Nikon AE and GO Classic. Of these 10x50s, it seemed easiest in the Nikon AE, it was most difficult in the GO Classic. Handheld - M1 was barely detected in any handheld 10x50s. It was not seen in handheld GO Classics.

M1 under mag 4.9-5.0 skies
Fujinon 10x50, M1 was seen only after concerted effort and chart reference.
Bushnell Legend 10x50 porro, just barely seen.
Nikon AE 10x50, at first only suspected, then just barely seen averted.
Nikon Action 10x50, took repeated tries to find it, even averted.
Not seen in any handheld or braced.

Nikon AE and Leupold seemed to do better than Pentax and Orion Ultraview
Nikon AE and Bushnell did better than Nikon Action
Bushnell did better than Nikon AE
Nikon AE, Pentax and Orion did better than Garrett
Oberwerk Mariner, Nikon AE and Leupold did better than Garrett and Oberwerk

Summary
Nikon Action - 10x46, 6.5°, er=9mm, IPD=56-73, cf=20ft, fmc/fc
The Nikon Action has the widest fov 6.5°, has one of the best on axis resolution measures, but it has very poor outer fov sharpness. It has no functioning internal baffles and is poorly blackened. However, it does illuminate the exit pupil very well. But it is poor mechanically and ergonomically, with a wobbly eyepiece bridge and the shortest eye relief of 9mm. In recent testing, I had to refocus this one at least a half dozen times during the session. Mechanical build, very short eyerelief, poor outer fov, lack of proper baffling and reduced aperture all lower the score on this one.

Oberwerk 10x50 - 10x43, 6.4°, er=13mm, IPD=58-72, cf=30ft, fmc/fc
The Oberwerk has near the widest fov 6.4°, has a very sharp outer fov, has very good on axis resolution. However, it has no internal baffles or blackening, the field stop is blurred, it has significant internal vignette and it does not illuminate the exit pupil very well. It has the greatest amount of aperture reduction, in this case due to too small prism shelf aperture. It is the too-small prisms that are contributing to the poor internal vignette and poor illumination.

Leupold Wind River Mesa - 10x48, 5.3°, er=17mm, IPD=58-74, cf=23ft, fmc/fc
The Leupold has only a 5.3° total fov. It has excellent outer field sharpness, one of the best. However, it has poor on-axis resolution, one of the worst. Also it delivers light very poorly across the exit pupil, shows considerable tilt in the light path and has a very low total exit pupil illumination score.

Garrett Genesis - 10x44, 6.1°, er=16mm, IPD=60-74, cf=25ft, fmc/fmc
The Garrett Genesis is the original name of the Garrett Classic. The Garrett looses significant points for the reduction of aperture, but does a few other things very well. It has good resolution, delivery of light is well balanced across the exit pupil, and the exit pupil is very well illuminated. However, it shows some off-axis internal reflections, field sharpness falls of rather quickly after 70%, and lower end (narrow) IPD is limited. Loss of field sharpness and reduction of aperture keep the score down in an otherwise decent performing binocular.

Oberwerk Mariner 10x60 – 10x52, 5.1°, er=21mm, IPD=61-73, cf 50ft, fmc/fmc
Also included in this report is the Oberwerk Mariner 10x60, due to the fact its effective aperture is 10x52. The Mariner is stopped down by internal baffles that are too narrow an opening. Eye relief is so long it can cause blackout issues if handheld up close to the eyes. The 5.1° fov makes it one of the narrowest. It has very good outer field sharpness, better than most of the others. Resolution is average. However, the Mariner scores very poorly in internal vignette and illumination of the exit pupil. It has greater axial tilt and lower illumination than any other 10x50 in this comparison. The limiting magnitude results reflect the poor scores above in that, on occasion, this “10x60” was equaled or exceeded by other 10x50s. Diopter is difficult to adjust and eyecups do not hold intermediate position. But, due primarily to dramatic reduction in aperture and poor measures in illumination, LM and axial tilt, the Mariner scored very low in rank. Like the Garrett, were it not for the dramatic reduction in aperture and the accompanying loss of illumination and LM, this binocular would score respectably in the average range of all 10x50s.

Orion Ultraview - 10x46, 6.0°, er=13mm, IPD=59-71, cf=20ft, fmc/fmc
The Orion has very nce coatings and is the lightest binocular in the group. But, it has poor outer fov sharpness. It has considerably reduced aperture due to prism edges exposed on the prism shelf. Eye relief is a short 13mm. Baffles and blackening are below average. Resolution is below average and it shows considerable tilt in the optical axis. These issues account for why the Orion Ultraview scored the lowest of all 10x50s.

Pentax PCF WP - 10x49, 5.0°, er=13mm, IPD=57-74, cf 20ft, fmc/fmc
It has the smallest fov at 5.0°. But is has one of the sharpest outer fovs of any binocular. It has a limited adjustability to the push/pull eyecups, but is otherwise very well built. It has very little reduction of aperture or internal vignette. The Pentax losses most of its points for poor resolution and narrow fov. Other than that it performs pretty well.

Bushnell Legend - 10x46, 6.4°, er=14mm, IPD=59-72, cf=25ft, fmc/fmc
The Bushnell also losses points due to reduction in aperture. Significant intrusion into the light path by the front prisms reduces effective aperture even more. Also, normal resolution was below average and boosted resolution was extremely poor, possibly indicating some aberrations. However, it has the widest fov at 6.4° and the field is quite sharp and mostly usable. The illumination of the exit pupil is well balanced and strong, and limiting magnitude test shows it very capable. Although heavy, it scores well mechanically and well overall.

Nikon Action Extreme - 10x48, 6.1°, er=13mm, IPD=56-73, cf=20ft, fmc/fc
The Nikon AE is sound mechanically and has some of the best ergonomics. Normal resolution is below average, but boosted resolution is one of the best. The aperture shows only minor reduction. Coatings do not rank as the best, but internal vignette is well controlled and illumination is good. There are no internal reflections. Limiting magnitude always scores well. Outer field sharpness falls off at 60% out, but holds on fair out to 80%. Eye relief is not ample at 13mm, but there is no chance of hitting the well recessed eye lens with your eyeglasses. Eye cups are widely adjustable and IPD covers a wide range. Diopter is very easy to adjust. Overall, the Nikon AE scores the highest of the 10x50s, but not by much over the Pentax. Each does some things slightly better than the other.

Garrett Genesis, Oberwerk, and Nikon Action, not by a significant difference, offer three 10x50s that measure up just a bit better than the Orion Ultraview.

Leupold Wind River, Bushnell Legend and Pentax WP, are all a step above those other four 10x50s, but a step below the Nikon Action Extreme.

Just a few notes on the benchmark model included here.
Fujinon FMT-SX - 10x50, 6.7°, er=13mm, IPD=57-76, close focus 50ft, lens fmc/prisms fmc,
None of these other binoculars come close to the performance of the Fujinon FMT-SX 10x50. When I find myself searching for a difficult object like M1 or M78, I pull out the Fujinon 10x50 to locate it. When I’m trying to see a faint star and need to confirm if it is at the location I suspect, I pull out the Fujinon to verify it. Contrast and light transmission in the Fujinon is immediately apparent as better than any other binocular in this group. The Fujinon has no aperture reduction. The field of view is a dramatic 6.7°, wider than any other 10x50 here, and in fact, wider than advertised. The field sharpness is truly sharp to the edge. It has the least overall aberrations and the least field curvature, yet it still has some decent apparent depth of field. It is by far the heaviest at 49oz. (1400g.) and has short eye relief of 13mm, but these seem a small price to pay for such excellence. Focus is precise and achieves pinpoint stars that are excellent. Limiting magnitude exceeds most of the other 10x50s by 0.3 to 0.5 magnitudes. Internal vignette is extremely well controlled, illumination is quite high and resolution ranks among the best. Let there be no doubt, these are all reasons why the Fujinon FMT-SX scored the highest of all binoculars out of 34 in this study, and you can see the difference the moment you put them up to your eyes!

For actuals scores and rank see
Small Binoculars - The Score

edz

Edited by EdZ (03/03/08 05:05 PM)

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