Measured 2026-07-25 · R.M.SKU CAL-GLS-1042

Field 10×42

Name: Field 10×42 — Calibrated Supply Co.
Brand: Calibrated
SKU: CAL-GLS-1042
Price: 649.00 USD
Availability: InStock
Rating: 4.8 (268 reviews)

Roof-prism binocular, ED glass, magnesium body

4.8 / 5268 reviews

A 10×42 with ED glass and a 4.2 mm exit pupil at 742 g. Every number that decides low-light performance is in the table, including the ones that are not flattering.

$649.00

CAL-GLS-1042 · USD

In stock

Qualifies for free standard shipping · 3–5 business days
60-day returns. One-time purchase — no subscription and no recurring charge.
Weight 742 g / 26.2 oz, measured 2026-07-25 on A&D EK-6100i, ±1 g. The same numbers are printed on the Field Card in the box.

Your card statement will show CALIBRATED SUPPLY for this order, not “Calibrated”. Questions? support@calibratedsupply.com · +1 (714) 269-7133.

Measured

How we measure

Weight

742 g / 26.2 oz

Body only, caps and strap off.

Exit pupil

4.2 mm

42 mm objective divided by 10× — the number that decides low-light performance.

Field of view

112 m at 1,000 m / 336 ft at 1,000 yd

Close focus

1.9 m / 6.2 ft

Eye relief

17.5 mm

Measured to the eyecup down. Enough to glass in glasses.

Waterproofing

IPX7, nitrogen purged

1 m for 30 minutes, then a thermal cycle to check for internal fogging.

Taken 2026-07-25 on A&D EK-6100i, ±1 g by R.M.. The same values are printed on the Field Card in your box, so the page and the carton can never disagree.

What it is made of

ED objective elements
Cuts the purple fringe on a backlit ridge line. The reason this costs what it costs.
Magnesium chassis742 g
Lighter than aluminium at the same stiffness.
Phase-corrected prisms
Dielectric coated. Resolution you can see at last light.
Tripod thread1/4-20, in the hinge
Adapter included. Glassing handheld past ten minutes is wasted effort.

The full description

The specification that decides whether a binocular is any good in the last twenty minutes of legal light is exit pupil, and it is arithmetic rather than marketing: objective diameter divided by magnification. This is a 10×42, so it is 4.2 mm. An 8×42 would give you 5.25 mm and would be the better low-light choice — we sell that number rather than hide it.

ED elements, phase-corrected and dielectric-coated roof prisms, a magnesium chassis, nitrogen purged and sealed to IPX7. Eye relief is 17.5 mm, which is enough to use with glasses on, and the eyecups have three detents rather than a smooth twist that creeps.

The tripod adapter is in the box rather than sold separately, because glassing handheld for more than about ten minutes finds almost nothing. Put it on the Carbon Glassing Tripod and you will see animals you were previously walking past.

Bought for

Open-country glassing and any hunt where you find animals before you move on them.

Not for

Timber whitetail hunting at short range in low light. An 8×42 has a bigger exit pupil and a wider field, and it is the better tool for that hunt.

Field notes

01Set the dioptre once, in daylight, on a hard edge at 100 yards. Then leave it alone.
02Glass in a grid off a tripod: pick a line, work it slowly, drop and repeat. Panning finds nothing.
03Eyecups down if you wear glasses. If you see a black ring, you are too far back, not too close.

On the bench

4.2 mm

exit pupil — the number that decides last light

26.2 oz

measured weight, body only

Our own testing, on production samples, with the method stated in the spec table above. Nothing here is a claim about what will happen on a hunt.

In the box

Field 10×42
Tripod adapter, 1/4-20
Objective and ocular caps
Neck strap
Padded case
Field Card with the serial and the measured weight of your unit

Construction, care and warranty

Construction: Magnesium alloy chassis with rubber armour; ED glass objective elements; phase-corrected BaK-4 roof prisms with dielectric coating; fully multi-coated air-to-glass surfaces; nitrogen purged, o-ring sealed to IPX7; three-detent twist eyecups; 1/4-20 tripod thread in the hinge under a screw cap.
Care: Blow grit off before touching a lens. Lens pen or a microfibre cloth only, never a shirt tail. Store with the caps off in a dry place — sealed cases hold moisture against the armour.
Warranty: Lifetime on optical and mechanical defects, transferable. Damage from a drop or from a vehicle is covered at a flat repair charge rather than not at all — ask before you assume it is not worth sending in.
Bought for: Western, Whitetail, Late season
SKU: CAL-GLS-1042
Price: $649.00 USD

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