Nikon 440 Clutter Test

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Matt Markworth
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Nikon 440 Clutter Test

Post by Matt Markworth » Sun Dec 29, 2013 9:00 pm

Hi All,

Some of the recent tests on the Trupulse 200X by Bob and Karlheinz got me thinking, and today I set up a test for my Nikon 440. The basic premise of the test is to create a window to shoot through to get to the target, therefore creating clutter in front of the target. The clutter was represented by a piece of cardboard with a circle cut out, positioned 30' away from the target. Test 1 utilized a 6" diameter cutout, and Test 2 utilized a 2.5" diameter cutout.

Here are the details of how the test was set up:

Place - Level football field.

Target - An off-white sheet of paper positioned at eye level.

Clutter - Cardboard with 2 cut out circles, diameters of 6" and 2.5".

Instrument - Nikon 440, which was handheld.

Conditions - Overcast, relatively low light conditions in the afternoon.

Other equipment - A pole to hold the target and a pole to hold the cardboard with cut out circles. A 300' tape.

Results: Shooting through the 6" diameter cutout was no problem and shooting through the 2.5" diameter cutout worked all the way out to 270' from the target. I was impressed that the unit allowed me to hit a target 270' away, while shooting through a 2.5" circular window that was 240' away. Using a tripod would have made it easier at the farther distances. It would be interesting to make the cutout even smaller and see how much "clutter" the unit can shoot through while on a tripod.

I also used the set up to check the calibration and confirmed what I previously knew about my Nikon 440. It shoots a little long at farther distances and requires a correction.

Measurement Protocol - I moved back to find the point right before clickover, which is the farthest actual distance for the displayed distance. I required 5 consecutive shots with the same reading.

Test 1: Shooting through the 6" diameter cardboard cutout, that was positioned 30' away from the target.
Test 2: Shooting through the 2.5" diameter cardboard cutout, that was positioned 30' away from the target.
Nikon 440 Clutter Test.PNG
Nikon 440 Clutter Test.PNG (7.47 KiB) Viewed 2099 times
Matt

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Will Blozan
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Re: Nikon 440 Clutter Test

Post by Will Blozan » Mon Dec 30, 2013 10:00 am

Matt,

Nice study! When I received mine many years ago I also experimented with the beam and found it to be very tight and seemingly unaffected by passing through a hole.

Now, if someone would put that laser into a instrument with the built in clinometer we would be golden.

Will

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dbhguru
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Re: Nikon 440 Clutter Test

Post by dbhguru » Mon Dec 30, 2013 1:48 pm

Matt, Will, Karl, et. al.

Good experiment. I hope others will follow the lead. We, as Ents should be doing a lot of this sort of thing.

Bob
Robert T. Leverett
Co-founder, Native Native Tree Society
Co-founder and President
Friends of Mohawk Trail State Forest
Co-founder, National Cadre

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Matt Markworth
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Re: Nikon 440 Clutter Test

Post by Matt Markworth » Mon Dec 30, 2013 7:17 pm

Bob, Will, All,

I got lucky and scooped up a gently used Trupulse 200 for a great deal on ebay. It arrived today in excellent condition and all the functionality works. Measurements on the trees in my front yard are in line with what I would expect . . . so, more tests will be forthcoming!

Matt

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dbhguru
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Re: Nikon 440 Clutter Test

Post by dbhguru » Mon Dec 30, 2013 9:02 pm

Matt

Congratulations. You have joined a select club of TruPulse owners. Will has a 360. Larry has a 200. Don Bragg has a 200. Michael Taylor has a 360. Karl Heinz has a 200X, and I have a 360 and a 200X. Doug Bidlack has TruPulse, although I'm unsure of the model. There may be others out there.

Bob
Robert T. Leverett
Co-founder, Native Native Tree Society
Co-founder and President
Friends of Mohawk Trail State Forest
Co-founder, National Cadre

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Matt Markworth
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Re: Nikon 440 Clutter Test

Post by Matt Markworth » Wed Jan 01, 2014 8:00 pm

All,

Here's another test on the Nikon 440. This test didn't include any "clutter", just the distance to a 10" x 10" piece of brown cardboard.

I used the same technique of moving back until the point just before clickover. The results provide more confirmation that the unit shoots short at closer distances and shoots long at farther distances, therefore requiring a correction for the farther distances. Still, it's impressive that all of the measurements were within the displayed accuracy of the unit (.5 yards). Conditions were partly cloudy and brighter than my last test.
nikon 440 distance test 3.PNG
nikon 440 distance test 3.PNG (10.5 KiB) Viewed 1986 times
Matt

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Karlheinz
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Re: Nikon 440 Clutter Test

Post by Karlheinz » Thu Jan 02, 2014 10:03 am

Hello Matt,

I am thrilled with your simple idea of ​​sending the beam through a round pinhole to simulate clutter. So you can still compare in the simplest way the width of laser beams with each other. I am sure you now soon bring the comparison to TP200. I already wait for it quite tensely!

In any case, you have impressively demonstrated that Nikon440 has a narrow beam, which was previously always just wordy claimed.

Some rangefinders also have filter functions that can hide unwanted reflections from targets with different distance. TP200 and Nikon550 know Farthest and Closest mode, TP200X has the additional Gate option and Impulse200LR has Short Gate and Long Gate. These functions are more or less effective.

Now the very interesting question: Can such filter functions make it possible, even with a broad beam to measure through such a tight hole, and thus can compensate for the disadvantage of a wide beam?

Karl (who is very exited)

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tsharp
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Re: Nikon 440 Clutter Test

Post by tsharp » Thu Jan 02, 2014 11:25 am

Excited Karl:
Maybe Rand Brown will weigh in. He modified his Nikon 550 by narrowing the beam by placing a piece of light cardboard with a hole punched in it over the aperture. I believe he was happy with the results.
Turner Sharp

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Matt Markworth
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Re: Nikon 440 Clutter Test

Post by Matt Markworth » Thu Jan 02, 2014 8:09 pm

Karl,

Thanks for the kind words and the ideas! I really like the idea of testing the closest and farthest modes.

The test I'm envisioning is positioning the tripod-mounted Trupulse 200 at a distance of 100m from the target. The laser and the target would stay in place, with only the circular cutouts being moved in increments of 10m. All modes would be tested at the various distances. The manual says, "In Closest and Farthest Modes, the minimum separation distance between targets is approximately 20 meters." If this holds true in my testing, then that would limit the usefulness of the farthest mode when measuring trees in a cluttered environment.

Here are the 3 things that I would attempt:

1) Finding the smallest circular cutout that the closest mode can no longer detect should have a correlation to the size of the beam.

2) Finding the smallest circular cutout that the standard mode can penetrate through should simulate how well the laser does in a cluttered environment and provide a comparison to the Nikon 440.

3) Finding the smallest circular cutout that the farthest mode can penetrate through should provide a comparison of it's effectiveness versus the standard mode.

I'll be heading back out to the football field soon to do some testing!

Matt

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KoutaR
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Re: Nikon 440 Clutter Test

Post by KoutaR » Fri Jan 03, 2014 2:07 am

Matt and others,

The idea is really brilliant, it is strange that nobody has found it earlier. What the best, the test measures the effective beam width or the effective clutter penetration capability, not the formal beam width given in specifications.

Matt, had you selected the Farthest Mode for the test?

Kouta

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