Why an Angled Rangefinder?

I enjoy optical exploring of nature and urban architecture.

The idea of an angled rangefinder occurred to me one day when I wanted to measure the height of the large pine and oak trees behind my house, to determine if they ever fell over would they fall on the roof of my house.

Soon I began to explore my natural and urban environments with an angled rangefinder, and I discovered I was exploring more. In the past, I observed nature and the city as a flat plane, usually width and sometimes depth. However, with the help of a rangefinder that measures both distance and angle, I now observe my natural and urban environments in three dimension: width, depth, and height. I think the key to 3-D observing is writing down the widths, distances, and heights as you encounter various objects.

How tall is that tree?
At what height in the tree is that nest?
How far away is that building?
How tall is that building?
How far is that deer?
What is the angle of that slope?
How high is that cliff?
How long is that bridge?
How far above the water is that bridge?
How close can I get to that wild animal?
And so on.

Here is what I found out as I researched rangefinders and angle measurement.

Angled Rangefinder: Optic for Hunters

I compared three rangefinders.

Bushnell Legend 1200 ARC
Leupold RX-1000 TRB
Nikon Monarch 1200

The Bushnell and Leupold both have an internal inclinometer and software for calculating bow and rifle trajectory, as well as distance and angle. The Nikon just measures distance. I like the feel and simplicity of the Nikon. However, since I want to measure both distance and height (trees, cliffs, buildings, etc.), I concentrated my testing on the Bushnell and Leupold.

Here are manufacturer's links to the tested rangefinders.

Bushnell Legend 1200 ARC
http://www.bushnell.com/products/rangefinders/legend-1200-arc/

Bushnell Legend 1000 ARC
(Click on "View the Commercial")
http://www.bushnell.com/products/rangefinders/scout-1000-arc/

Leupold RX-1000 webpage
http://leupold.com/hunting-and-shoot...r-rangefinder/

Leupold RX-1000 Videos
(Click on "Videos" at above link)

I decided to keep the Bushnell for the following reasons.

Out-of-the-box reasons

(a) Waterproof, fogproof.

(b) Tripod hole in bottom of rangefinder.

(c) 2-yr warranty.

(d) Ranged in 1st priority, last priority, and scan mode.

(e) LCD reticle inside viewfinder more natural and free of clutter.

(f) Range of 1200 yards (reflective building), 800 yards (tree), 600 yards (deer).

(g) Canvas case has magnet closure (less noise than snap).

Performance reasons

(h) Leupold failed to return measurement at 280 yards on bright sunny day, while Bushnell and Nikon did return measurements.

(i) Leupold LED reticle in viewfinder is too bright, actually destroys night vision and makes ranging almost impossible if using during low light situations.

(j) Bushnell matched range measurements with the Nikon on every occasion, while the Leupold was off by one or more yards (distance) and degrees (angle).

(k) Trajectory function of Bushnell appeared to work smoother than Leupold. Easier to select rifle caliber.

(l) Bushnell has 1st priority mode (target), last priority mode (bush), and scan mode, while Leupold only has last priority mode and scan mode. In hunting terms, 1st priority mode is good when deer is first in sight with brush or trees in background; 1st priority ranges first object the laser encounters, in this case the deer and not the brush or trees in the background. Last priority mode is good when deer is last in sight with tall grass or brush in the foreground; last priority ranges the last object the laser encounters.

Angled Rangefinder: Optic for Naturalists

My purpose for the Bushnell rangefinder is to measure distance and height in nature and urban settings. I also purchased a Texas Instruments pocket scientific calculator (TI-30X IIS) to figure sine of slope angle and slope distance to determine height. Think in terms of trigonometry--angles and sides of right triangle, which you form when you stand in front of a tree, cliff, or building. Here are a few links to tree measurement at the Eastern Native Tree Society (ENTS).

ENTS home page
http://www.nativetreesociety.org/

ENTS Tree Measurement Index
http://www.nativetreesociety.org/measure/index_measure.html

ENTS Tree Measuring Guidelines
http://www.nativetreesociety.org/bulletin/b1_1/B_ENTS_v1_01_sec4_FA01.pdf

Tree Measuring with Laser and Clinometer Video
(Colby Rucker uses separate laser and clinometer; the Bushnell rangefinder I use has built-in clinometer)
http://www.youtube.com/watch?v=0WFUpbv8Mhg

Great Eastern Trees (pp. 6-40)
(Greatest trees listed by state)
http://www.nativetreesociety.org/bulletin/b3_4/B_ENTS_v03_04.pdf

Well, there you have my research and selection of an angled rangefinder--a hunting optic to measure tree height, cliff height, and building height.

...Bob
Kentucky

Last edited by BobinKy; 10/11/09.

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Bob