Kowa Genesis 33 8x33 vs Kowa BD III XD 8x42
Quick take: The Kowa BD III XD 8x42 costs $651 less; the Kowa BD III XD 8x42 has a wider field of view (429 vs 420 ft @ 1000 yds); the Kowa BD III XD 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
Whether fluorite-crystal glass is worth $651 is the whole question here, because on paper the cheaper Kowa wins on most specs. The Kowa BD III XD 8x42 shows 429 ft at 1000 yards against the Genesis's 420, a 5.25mm exit pupil against 4.1mm, and 17.2mm of eye relief against 15mm, at 21.3 oz to the Genesis's 20.8. It carries fluorite-rich XD glass in a magnesium body, and it costs $499.
What the Kowa Genesis 33 8x33 adds is Prominar XD fluorite-crystal glass from Kowa's flagship line, and owners describe the result as flawless color correction, with one review reporting zero discernible chromatic aberration. Testers comparing them directly judge it optically equal to a Leica Ultravid HD 8x32. It focuses to 4.9 ft against 5.9, with minimal field collapse up close, which makes it one of the better premium binoculars for butterflies, and owners say its compact body suits smaller hands.
The owners' complaints matter for this comparison. Short eye relief is the recurring one, with glasses wearers losing the edges of the field. The focuser is stiff and slow at 1.6 turns close to infinity, the eyecups have only two intermediate stops, and the rainguard and case feel cheap at this price. Owners themselves point out that Kowa's cheaper XD line delivers much of the experience for a fraction of the money.
For most birders, glasses wearers especially, the BD III is the better buy. The Genesis 33 rewards someone who sees the difference between very good and excellent color correction, wants a compact travel binocular, and has confirmed the eye relief works for them.
Kowa Genesis 33 8x33
Worth the premium for a birder without glasses who wants alpha-grade color correction in a compact, light travel binocular.
Kowa BD III XD 8x42
The better buy for most birders, glasses wearers especially: wider, brighter and longer in eye relief, for $651 less.
| Spec | Kowa Genesis 33 8x33 | Kowa BD III XD 8x42 |
|---|---|---|
| Approx. price | ~$1,150 | ~$499 |
| Use case | Birding | Birding |
| Magnification | 8x | 8x |
| Objective | 33mm | 42mm |
| Exit pupil | 4.1mm | 5.25mm |
| Field of view | 420 ft @ 1000 yds | 429 ft @ 1000 yds |
| Eye relief | 15mm | 17.2mm |
| Close focus | 4.9 ft | 5.9 ft |
| Prism | Roof | Roof |
| Glass | FL | ED |
| Coating | Fully Multi-Coated | Fully Multi-Coated |
| Weight | 20.8 oz | 21.3 oz |
| Dimensions | 5.1 x 4.7 in | 5.3 x 5.0 in |
| Warranty | Limited Lifetime | Limited Lifetime |
Feature comparison
Kowa Genesis 33 8x33
- ✓ED Glass
- ✓Phase-Corrected
- ✓Dielectric Coating
- ✓Waterproof
- ✓Fogproof
- ✗Image Stabilized
- ✗Tripod Adaptable
- ✓Magnesium Body
- ✓Locking Diopter
Kowa BD III XD 8x42
- ✓ED Glass
- ✗Phase-Corrected
- ✗Dielectric Coating
- ✓Waterproof
- ✓Fogproof
- ✗Image Stabilized
- ✗Tripod Adaptable
- ✓Magnesium Body
- ✗Locking Diopter
What birders say
Kowa Genesis 33 8x33
- ✓Prominar XD fluorite-class glass with essentially no visible color fringing — one owner review flatly reported 'zero discernible chromatic aberration'
- ✓Forum reviewers judge it 'optically equal' to the Leica Ultravid HD 8x32 — a binocular that costs nearly twice as much
- ✓Wide 420 ft field of view with a crisp, bright image boosted by phase coating and a dielectric C3 prism coating
- ✓Outstanding 5 ft close focus with minimal visual field collapse — a genuine butterfly and dragonfly instrument
- ✓Light and compact: 22.2 oz on a magnesium frame, about 5.25 inches long — easy all-day carry
- ✓Thoughtful ergonomics with broad, shallow thumb divots on the underside — reviewers note it especially suits smaller hands
- ✓Slow, precise 1.6-turn focuser rewards deliberate focusing and holds position securely
- ✓Repeatedly called 'the best kept secret in premium midsize binoculars' on birding forums — alpha-level glass at roughly half alpha price
- ✗Eye relief is only 15mm and multiple reviewers flag it as 'a bit on the short side' — eyeglass wearers can struggle to see the full field
- ✗The focus mechanism is stiff and slower than average at 1.6 turns close-to-infinity — quick birding refocusing takes more effort
- ✗Eyecups offer just two intermediate stops, limiting fine adjustment for non-glasses users
- ✗The rainguard is hard plastic rather than flexible rubber — a cheap-feeling accessory on a $1,100 binocular
- ✗The included case lacks a shoulder strap or belt loop attachment
- ✗Kowa's small dealer footprint and marketing mean low brand recognition and thinner resale demand than Zeiss, Leica, or Swarovski
- ✗The focus stiffness reviewers hope will 'loosen with extended use' is a break-in gamble at this price
- ✗At $1,100+ it faces its own stablemate problem — the Kowa BD II XD line delivers much of the experience for a third of the money
Kowa Genesis 33 8x33 vs Kowa BD III XD 8x42: common questions
Is the Kowa Genesis 33 8x33 worth $651 more than the Kowa BD III XD 8x42?▾
Only if color correction is what you notice. Genesis owners report essentially no visible fringing and judge it equal to a Leica Ultravid HD 8x32, but they also concede Kowa's cheaper XD binoculars deliver much of the experience. The BD III XD 8x42 has the wider field, bigger exit pupil and longer eye relief.
Can glasses wearers use the Kowa Genesis 33 8x33 as easily as the BD III XD 8x42?▾
Probably not. The Genesis has 15mm of eye relief, and owners repeatedly report glasses wearers losing the field edges. The BD III XD 8x42 has 17.2mm, so if you bird in glasses it is the safer choice, or try the Genesis in person first.