Nikon Prostaff P3 8x42 vs Nikon Action EX 8x40
Quick take: The Nikon Action EX 8x40 has a wider field of view (430 vs 377 ft @ 1000 yds); the Nikon Prostaff P3 8x42 gathers more light with a larger 42mm objective.
Field of view, to scale
Top-down view · drawn to true scale — no exaggeration
Which one to buy
Same $160, same 8x, two very different bodies: the Prostaff P3 8x42 is a 20.3 oz roof prism, the Action EX 8x40 a 30.1 oz porro. The Action EX is also discontinued, so it may be hard to find new, which tilts this toward the Nikon still in production.
What the porro buys you is width. Its 430 ft field is clearly bigger than the P3's 377 ft, and owners describe the view as extra wide, bright and deep, the classic porro look. Its 17.2mm of eye relief suits glasses, though the P3's 20.2mm is more generous still. The costs, by owner account, are boxy bulk, a soft outer 20% of the field, and the porro habit of drifting out of collimation after a hard knock.
P3 owners describe the reverse trade: a sharp center, a body light enough to forget, and a 9.8 ft close focus against the Action EX's 16.4 ft. Its weak spots are slightly reserved brightness at dusk from its silver-coated prisms, some fringing on backlit birds, and throwaway caps and strap. Both are waterproof and fogproof with lifetime warranties.
The P3 is the better choice now for nearly everyone, mainly because it is lighter, current and easier to live with. The exception is the buyer who wants the widest, most immersive 8x view at this price and turns up a clean pair of the Nikon porro.
Nikon Prostaff P3 8x42
The default for most buyers: a light, current 8x42 that glasses wearers and birders on foot can carry all day.
Nikon Action EX 8x40
Skip it unless you find a clean pair and want the widest 8x view at this price; it is discontinued, so new stock may be hard to come by.
| Spec | Nikon Prostaff P3 8x42 | Nikon Action EX 8x40 |
|---|---|---|
| Approx. price | ~$160 | ~$160 |
| Use case | General Purpose | General Purpose |
| Magnification | 8x | 8x |
| Objective | 42mm | 40mm |
| Exit pupil | 5.25mm | 5.0mm |
| Field of view | 377 ft @ 1000 yds | 430 ft @ 1000 yds |
| Eye relief | 20.2mm | 17.2mm |
| Close focus | 9.8 ft | 16.4 ft |
| Prism | Roof | Porro |
| Glass | Standard | Eco-Glass |
| Coating | Fully Multi-Coated | Fully Multi-Coated |
| Weight | 20.3 oz | 30.1 oz |
| Dimensions | 5.7 x 5.1 in | 5.4 x 7.4 in |
| Warranty | Limited Lifetime | Limited Lifetime |
Feature comparison
Nikon Prostaff P3 8x42
- ✗ED Glass
- ✗Phase-Corrected
- ✗Dielectric Coating
- ✓Waterproof
- ✓Fogproof
- ✗Image Stabilized
- ✓Tripod Adaptable
- ✗Magnesium Body
- ✗Locking Diopter
Nikon Action EX 8x40
- ✗ED Glass
- ✗Phase-Corrected
- ✗Dielectric Coating
- ✓Waterproof
- ✓Fogproof
- ✗Image Stabilized
- ✓Tripod Adaptable
- ✗Magnesium Body
- ✗Locking Diopter
What birders say
Nikon Prostaff P3 8x42
- ✓Class-leading on-axis sharpness - forum reviewers call it probably the sharpest roof prism you can buy near $100
- ✓Remarkably lightweight for a full-size 42mm roof - one of the lightest phase-coated 8x42s made, great for all-day carry
- ✓Generous 20mm+ eye relief with click-stop eyecups makes it one of the most eyeglass-friendly budget binoculars available
- ✓Fully waterproof and nitrogen-purged fogproof - a huge step over porro-prism rivals like the Aculon A211 at similar money
- ✓Wide 7.2-degree field of view, unusually generous for a budget roof and a clear upgrade over the old Prostaff 3s
- ✓Phase-corrected prisms at a price point where many competitors skip them - contrast and resolution punch above the price
- ✓Comfortable, grippy rubber armor and a simple, snag-free body that owners describe as 'disappearing in the hand'
- ✓Widely regarded on forums as a significant optical improvement over its Prostaff 3s predecessor for barely more money
- ✗Silver-coated (not dielectric) prisms mean the image is a touch dimmer than the Prostaff P7 or Monarch M5 - noticeable at dusk
- ✗No ED glass, so chromatic aberration shows as color fringing on backlit birds and high-contrast edges
- ✗Accessories are bare-bones: unpadded webbing strap, a foam pouch, and lens covers that don't attach and famously get lost
- ✗Edge sharpness falls off in the outer portion of the field - fine for spotting, less fine for panning landscapes
- ✗Some eyeglass wearers report slight vignetting at certain eyecup positions - worth testing before the return window closes
- ✗Focus wheel is functional but not luxurious; a few owners describe slight stiffness in cold weather
- ✗Close focus is unremarkable, so butterfly and dragonfly watchers often look elsewhere
- ✗Plastic-heavy chassis keeps weight down but doesn't feel as substantial as the Monarch M5's build
Nikon Action EX 8x40
- ✓Exceptionally wide 430 ft (8.2 degree) field of view - forum users describe the view as extra wide with extremely bright colors
- ✓17.2mm eye relief is outstanding at this price and lets eyeglass wearers see the whole field
- ✓Fully waterproof, fogproof, and nitrogen purged - real weather sealing that the cheaper Aculon line lacks
- ✓Owners who have both lines prefer the Action EX over the Aculon: improved eyepieces, a larger and clearer sweet spot, and less chromatic aberration
- ✓BaK-4 Porro prisms deliver the bright, deep, 3D image quality that makes porros beloved at budget prices
- ✓Reviewers call it an outstanding entry-level binocular - optically good and robustly weather resistant for the money
- ✓Rugged rubber-armored body that shrugs off field abuse
- ✓Tripod adaptable, and the bright wide field makes it a pleasant casual astronomy glass too
- ✗Edge sharpness is the known trade-off - astronomy users report stars blurring in roughly the outer 20% of that huge field
- ✗Heavy for an 8x40 at 30.1 oz - over half a pound more than typical 42mm roof binoculars
- ✗Classic Porro bulk: wide, boxy, and not remotely pocketable or compact around the neck
- ✗Porro prisms are more susceptible to going out of collimation if dropped or knocked - owners advise checking alignment on arrival
- ✗Optics are good but not high-end - no ED glass, so some color fringing appears on high-contrast subjects
- ✗Newer Chinese-made ED roof binoculars at similar prices have eroded its once-unbeatable value position
- ✗16.4 ft close focus is poor for butterflies, dragonflies, or feeder-distance birding
- ✗An aging design in a Nikon lineup that keeps shuffling, so availability and pricing fluctuate
Nikon Prostaff P3 8x42 vs Nikon Action EX 8x40: common questions
Is the Action EX 8x40's wider field worth the extra weight over the Prostaff P3 8x42?▾
For immersive views of flocks, landscapes or the night sky, owners say the 430 ft field is the Action EX's best trait. For carrying on a trail, the P3 8x42's 20.3 oz is far easier than 30.1 oz, and its 377 ft field is already generous for a budget roof prism.
Which holds up better, the Nikon Action EX 8x40 or the Prostaff P3 8x42?▾
Both are waterproof, fogproof and rubber armored. Action EX owners warn that porro prisms can go out of collimation after a hard drop and suggest checking alignment on arrival, a risk the roof-prism P3 8x42 doesn't carry in the same way.