Nikon 8x42 Prostaff P7 vs Monarch M5

Field of view: the Prostaff P7 leads

At 1,000 yd the Prostaff P7 prints 377 ft, which is 7.2 degrees. Monarch M5 prints 335 ft, or 6.4 degrees. Both are 8x42 pairs, so the extra width comes from the eyepiece design, not the size.

Among the 75 models of this size with a field figure, the Prostaff P7 places 49th and the Monarch M5 places 71st. The median for the size is 393 ft, so the Prostaff P7 sits just under the middle and the Monarch M5 sits well under it.

Brightness at dusk: a tie

Both models work out to a 5.3 mm exit pupil. Nikon defines exit pupil as the effective objective diameter divided by magnification, and says a larger one gives a brighter view in dim light.

The twilight factor works out to 18.3 for each, and relative brightness works out to 27.6 for each. These are calculated from the 8x42 size, so the figures cannot separate the two. Any difference at dusk would come from glass and coatings, which the figures here do not measure.

Eye relief for eyeglass wearers: the Prostaff P7 by a small margin

Eye relief is 20.2 mm on the Prostaff P7 and 19.5 mm on the Monarch M5. The RSPB shop says eyeglass wearers should look for at least 16 mm, so both clear that line.

Audubon says binoculars made for birders offer 15 to 20 mm. Prostaff P7 sits at the top of that span, and Monarch M5 is just under it. The size median is 18 mm, so both beat it.

Close focus: the Monarch M5 leads

Down to 8.2 ft is how close the Monarch M5 focuses. Prostaff P7 stops at 9.8 ft. For butterflies, dragonflies or a feeder close to the window, the shorter distance lets you keep the subject sharp when it is near.

Neither model reaches the size median of 6.6 ft, so a reader who mostly watches insects at arm's reach will find both of them limited.

Weight and build: the Prostaff P7 is lighter, the Monarch M5 has ED glass

Weight is 20.8 oz for the Prostaff P7 and 22.2 oz for the Monarch M5. The size median is 24.2 oz, so both sit under it, and Prostaff P7 sits further under.

ED glass is on the Monarch M5, and Prostaff P7 does not list it. Nikon says ED glass reduces chromatic aberration to a remarkable degree. Tripod adapting is also listed for Monarch M5.

Both are roof prism models with center focus, an eye spacing range of 56 to 72 mm and nitrogen fill. Each is waterproof up to 1 m / 3.3 ft for 10 minutes with O-ring seals. Nikon says waterproof binoculars should not be used underwater.

Price band

Nikon lists both models in the same maker list price band of $200 to $500. The price band does not settle the choice, so the decision rests on the view, the weight and the close focus. For other models in the band, see binoculars in the $200 to $500 band.

Prostaff P7 8x42 or Monarch M5 8x42

The Prostaff P7 suits you if view width and low weight matter most. Monarch M5 suits you if you watch close subjects and want ED glass. Exit pupil, brightness figures and price band are level.