Delta Optics 9x45 Titanium HD-RF rangefinding binocular

The Delta 9x45mm Titanium HD-RF rangefinding binocular offers spectacular optical performance and ranging ability.

As a hunter I consider a high-quality binocular to be second in importance only to my rifle. I can’t imagine hunting any kind of big game animal without it.

Delta Optics 9x45 Titanium HD-RF rangefinding binocular — Delta optics use top quality HD fluoride glass to eliminate secondary chromatic aberration and a proprietary anti-reflective coating that allows 85 percent light transmission

It’s even better if you have a binocular that will measure the range for you. Combining binocular with rangefinder saves time by instantly ranging a game animal seconds after you spot it.

This is the first Delta optic I have reviewed and it’s surprisingly good.

The Delta Optics Technologies company, founded in 2002, is based in Singapore. I believe this top-of-the-range Delta optic was designed in Poland and made in Japan, a country whose quality hunting optics rival the best European brands at considerably lower cost.

The Delta binocular is built using a centre-bridge design. It has a titanium frame, weighs a solid 1kg and measures 154mm long, 127mm wide and 68mm high, which provides viewing steadiness.

The barrels are covered in rubber armour and the gripping surfaces have a textured finish providing a firm grip. Rubber armouring not only protects the binocular but muffles the sound of it banging against rifle or rocks if you allow it to swing about during a climb.

Each ocular eyepiece winds out and includes a dioptric adjustment ring; the left one corrects individual vision while the right focuses an illuminated red OLED display with five levels of brightness. The adjustment rings have the same textured rubber surface as the grasping area. The eyecups are rubber coated and click adjustable for use with and without eyeglasses.

The centre focusing knob is rather large and chequered, making it easy to turn with the finger tips to refine the focus while viewing. This knob houses the single CR2 battery that powers the Class One laser rangefinder.

The laser projecting device is contained in one barrel of the binocular. Two rubber switches control the programming and operation. These switches are located in front of the focus knob, one on either side of the centre hinge; the menu switch is on the right side and the main/OK switch is on the left.

Specifications tout the Delta as capable of reading at distances from 13.5m to 2377m. Accuracy is ±1 metre at 1000m and ±2 metres from 1000 to 2377m. Distance measurements can be displayed in metres or yards.

The Delta does not have any kind of a ballistic compensation calculator. However, it does have an internal inclinometer and will display the user’s choice of shot angle (vertical or horizontal) to ±70 degrees or the true horizontal distance.

Operation is simple: Press the operation button to activate the rangefinder, push the button again to range, or hold it down for scan mode, which produces a new readout every 0.25 seconds and feeds back a running commentary on moving or very small targets.

Inclement conditions such as rain, fog, snow and haze affect the unit’s capabilities. The aiming circle blinks when the unit is unable to provide a range.

AMAZING OPTICS

I was amazed by the Delta’s crystal clear optics, which are equal to almost any binocular I’ve ever tested. Contrast, sharpness and light transmission are shockingly good. Lenses are made of unsurpassable fluoride glass and are fully multi-coated for contrast, light transfer, reflection reduction and every other performance-enhancing element conceivable to engineer into a binocular.

A phase-corrected, high index BAK-4 prism is combined with HD glass to get the maximum or optimum contrast of images viewed, increase colour transmission and minimise colour fringing.

The size of a binocular’s exit pupils is also important to the hunter — the larger they are, the less critical is eye alignment. The pupil of the human eye varies in diameter in response to the intensity of the light it is metering, from approximately 2.5mm in bright sunlight to a maximum of around 7mm in total darkness. Based on my experience, a binocular used for hunting should not have an exit pupil smaller than 3mm, but I’d rather have 5mm.

The twilight factor (TF), a measure of resolution in marginal light, is the square root of the magnification multiplied by objective lens diameter.

The Delta 9×45 has a TF of 18.3 and an exit pupil of 5mm which is enough to brighten the target image in dim light.

A binocular’s field of view is influenced by several design factors including magnification, but for a given magnification, the larger the diameter of the ocular lenses, the greater the field of view. The Delta’s ocular lenses have a diameter of 19mm with an eye relief of 18mm. The field of view is 117m at 1000m, which means its field of view at 500, 100 and 50m is 58.5, 12 and 6m respectively.

To test the unit for ranging ability, I sat on a lookout on one side of a steep gorge and pushed the rangefinder as far as I could reliably get readings. Even when ranging into a lowering sun — a challenging test for a laser rangefinder — I was able to push the maximum factory-specified distance. On rocky bluffs on the farthest gorge, the Delta (rated 2377m) consistently produced range readings out to 3200m. It goes without saying, however, that you must hold it rock steady.

The Delta is fast, taking only .25 of a second for the computer to respond to a range. Evidently, it has a very fast, powerful ranging apparatus and processor — typically, the distance appeared almost instantly every time I pressed the button. For all practical hunting purposes, it surpasses what any hunter will ever need for taking ethical shots at game.

In early evening, while good light remained, I scanned distant bluffs away up the Turon and nearby boundary fence lines searching for distortion. I couldn’t detect any. Next I compared natural colours along the slopes and gullies — the green of fresh grass and river oaks, as well as browns and greys of brush. All were sharp and clear.

The Delta feels great in the hand and its laser switches are easy to manipulate. The readout is clear and sharp and its optical performance all that anyone could wish for. Better still, the price is affordable by the majority of hunters and shooters.

A bit on the heavy side, the Delta binocular is nonetheless outstanding.

SPECIFICATIONS