Weems & Plath BN50 PRO Operating instructions

10/2018

Individual Focus: (BN40, BN50, BN20C) e advantage of individual focus binoculars is that you can pre-focus the
binoculars, allowing you to see objects in low light without further adjustments for distances of 40 yards to innity. To
focus using individual focus system: cover one lens or close one eye at a time (it is better to cover a lens and leave both
eyes open) and rotate the opposite eye piece focusing (diopter) ring until the image is sharp, then repeat for the other side.
3. How to use with eye glasses:
Fold down rubber fold-down cups for use with eye glasses in order to obtain full image view. (BN20C, BN40, BN50)
Twist each eye-piece down for use with eye glasses. (BN10)
4. How to use the compass (BN20C)
A compass bearing can be measured using the built-in compass in the right half of the binocular body. It shows the
bearing to an object from the observer. Each graduation of the compass equals one degree of angle. When the object lies
north the compass shows 0°. It will increase as you turn clockwise. 90° means the object lies east of you. 180° means the
object is south and 270° means it is west.
In order to ensure precise angle measurements, keep the binoculars horizontal and level when reading the compass. The
object must lie in the center of the reticle.
The binocular compass is illuminated by holding the power button down while taking a reading at night or in low light
conditions. (Be sure batteries are installed [LR44]. See Warranty Information*)
How to use the reticle to measure distance (BN20C)
If you know the height of an object in meters, you can use the optical scale of
your binoculars to estimate the distance to the object.
First, use your nautical chart to determine the height of the object in meters.
Second, look through the binoculars and take note of the number closest to the
top of the object you see in the vertical number scale. Remember this number and find the
rotating ring on the slide rule on the outside of the left binocular barrel. Rotate the center
ring and match this number to the arrow on the “angle” indicator. Holding the center ring
stationary and looking across the ring to the middle row of numbers labeled “object size,”find
the known height of the object in meters. Read “Distance” to find the distance to the object in meters.
Example: A landmark on a chart is recorded as 12m tall. Looking through the binoculars, the landmark compares to 3
on the vertical number scale. Consult the rotating slide rule on the outside of the binocular and match the angle arrow
indicator to 3. Find 12 on the object size scale. Read directly across to see 400 meters on the distance scale.
How to care for your binoculars:
To protect lenses when not in use, cover with lens covers.
To clean lenses, wipe with lens cloth that comes with binocular or use soft, lintless cloth.
Dirt and smudges can be removed with one or two drops of isopropyl alcohol on cloth.
Store binoculars in moisture-free location and never take the binoculars apart.
10/2018
214 EASTERN AVE. • ANNAPOLIS, MD 21403 • USA 410-263-6700 • fax [phone] • www.weems-plath.com • E-mail: [email protected]
2 Year Warranty
Please see our website for more information and to activate your warranty.
www.Weems-Plath.com/Support