Nikon 440 Clutter Test

General discussions of measurement techniques and the results of testing of techniques and equipment.

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Karlheinz
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Re: Nikon 440 Clutter Test

Post by Karlheinz » Thu Jan 09, 2014 8:15 am

More results from Clutter Test:

The individual conditions were: Distance between the two panels 30' (9.15 m), instruments are mounted on tripod, target plate is painted red, pinhole panel is of natural fiber color. The wanted value is the maximum possible distance to the pinhole panel, where a reading through the hole is just even to get:

Nikon550:
Now I succeeded in measuring through the hole even with the Nikon550!
- Pinhole 2.5'' (6.35 cm): up to ~1 m (reading through the hole: 10.5 m).
(I had to aim very carefully, a little above the middle. Quite near to come towards the pinhole was not possible, because Nikon550 needs 10 m minimum distance. Better for future testing would be a distance of 10 m between the boards instead of 30').
- Pinhole 10 cm (3.93"): up to ~3 m (reading through the hole: 12,0 m)

Leica DistoD8:
- Pinhole 2.5'' (6.35 cm): up to ~200 m (reading through the hole: ~209 m).
Here the Leica has reached its limit of measurement range. I measured at twilight. Guiding the red laser beam was done by using the Scope of the TP200X, whose optics is still usable even at twilight.

TP200X:
- Pinhole 10 cm (3.93 "): up to ~16 m (reading through the hole: 25,5 m)
Targeting Mode was Standard (default value).
With pinhole 2.5” over a long distance I will yet repeat the test, when I have improved my arrangement, so that possible falsifications, when the laser spot becomes larger than the whole pinhole plate, can be excluded.


Matt,
if you still bring the comparative values for the TP200, we can compile the results of our five instruments in one table and compare! Your value for Nikon440 was 240' (73 m). That was freehand, maybe you can even improve by using a tripod.

Well of course would be, if further users would test and confirm our values. A cardboard with pinhole 2.5'' will be produced easily.


Karl

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Matt Markworth
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Re: Nikon 440 Clutter Test

Post by Matt Markworth » Sun Jan 12, 2014 4:09 pm

Karl, All,

I set up the Clutter Test again today and have 2 takeaways.

1) When the pinhole plate and target are only 30' apart, the farthest mode of the TP 200 provides no advantage over the standard mode. This is consistent with the manual, which states "In Closest and Farthest Modes, the minimum separation distance between targets is approximately 20 meters."

2) The clutter penetrating ability of the Nikon 440 continues to amaze me. I was able to get even better results by setting it on a tripod.


Target: Red posterboard
Pinhole Plate: 1m x 1m piece of brown cardboard, with a 2.5" hole
Distance between two panels: 30'
Instruments tested: TP 200 and Nikon 440, both mounted on a tripod
Desired Value: Maximum distance to the pinhole plate, at which I could still get a value for the distance to the target

TP 200
In both the standard and farthest mode, I was able to shoot through a 2.5" hole that was 15' away. The displayed value to the target was about 45' and varied a little with each firing of the laser. Based on these results, the Nikon 440 will continue to be my instrument of choice when shooting through heavy clutter. That being said, I've been very happy with the TP 200 when clutter isn't an issue.

TP 200 at 15' from the pinhole plate . . .
DSCN2072.jpg
Nikon 440
By setting the unit on a tripod (using a stretchy velcro strap), I was able to shoot through a 2.5" hole that was 411' away. The displayed value to the target was 147 yards, therefore equaling a distance of 441'.

NIkon 440 at 411' from the pinhole plate . . .
DSCN2068.jpg
Matt

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Karlheinz
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Re: Nikon 440 Clutter Test

Post by Karlheinz » Tue Jan 14, 2014 4:10 am

Here is an other test with Nikon550:
- Pinhole 30 cm: up to ~200 m (reading through the hole: ~209 m).
Pinhole 30cm.jpg
It turned out that I had chosen the hole for the test plenty big. A smaller one with 15 cm to 20 cm would allow a better comparison with TruPulse.

Karl

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Karlheinz
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Re: Nikon 440 Clutter Test

Post by Karlheinz » Tue Feb 04, 2014 10:28 am

Even more results from clutter test
Table Maximum distance
Table Maximum distance
My pinhole table with the set of interchangeable inserts
My pinhole table with the set of interchangeable inserts
The table shows the maximum distances to the pinhole plate, found by Matt and me, at which measuring through to a target plate 30' behind it just is possible. These values enable a comparative statement for the beam width and the clutter penetration between the tested rangefinders. You are invited to test also your equipment, so that the table can be continued or corrected!

Assuming that our rangefinders in the standard mode will evaluate and display only the strongest of all reflections, then applies: The limit value ‘maximum distance’ from the table indicates the distance at which the energy of the reflex from the target board through the hole is just a little more powerful than the reflex from the surrounding pinhole table. This gives us a slightly measurable value that allows a comparison of the beamwidth of different rangefinders.

The behavior of the Nikon 550 surprises. With increasing distance, the limit of ‘maximum distance’ is reached already at an remarkably early stage. Accordingly, the Nikon 550 has far the widest beam of all rangefinders. But when I increased the distance over the measured value ‘maximum distance’ far beyond, at some point of distance I obtained again a value measured from the target plate through the hole. Conspicuous in mode Dst (footnote (3)) is, that this change always takes place at 44 meters, regardless from the size of the pinhole. To the behavior in the mode 1st (footnote (2)), where the ranges of measurement through possible and impossible often change, I have no reasonable explanation.
Despite the wide measuring beam, under certain conditions the Nikon 550 thus can penetrate clutter amazingly well, it seems to work only from a certain distance constellation. So it must have undocumented filtering capabilities, which are only effective at larger distance constellations. To clarify this behavior in more detail, further measurements with altered distances between pinhole table and target plate is required. The Nikon fans in NTS should take care of it!


I think in order to better explain the behavior of the rangefinders, we can not help but to investigate the laser spot with even infrared indicators such as night vision and infrared camera. I do not have access to such equipment. I still hope that in this forum someone finds who can do it. As the laser spot (footprint) of the visible red beam of my Leica looks, I had already shown here: http://www.ents-bbs.org/viewtopic.php?f ... int#p21571. The image of the Leica laser spot shows a central strong laser core, surrounded by undulatory energy rings, getting weaker towards the edge.

The surface condition of the target plate has relatively little influence. For example, with the TP200X (mode Farthest, pinhole 100 mm) I got the following results: Target plate red 190 m, natural 195 m, white 210 m.

For all measurements to determine the limit 'maximum distance', I mounted the device on a tripod with a tilting head and I had to align it very precisely to the pinhole. With both of my instruments TP200X and Nikon 550 it was not done enough just to align the crosshairs on center hole. I had to scan the hole and its near surroundings with the laser to align the center of the laser beam precisely to the hole. This is also a highly suitable method to verify the correct alignment of the crosshairs. Unfortunately I found significant deviation not only at the Nikon 550, but also at my expensive TP200X. A readjustment by the user is not provided.


These measuring series has shown that for a precise point measurement, the Leica Disto D8 has the best focused beam. However, right after comes the Nikon 440. The TruPulse instruments in contrast, have a much wider beam. The Nikon 550 has the far broadest beam of all tested instruments, but in certain distance constellations it is capable to penetrates clutter significantly better than the Trupulse200, which has scarcely effective filter functions. The TruPulse200X with its well functioning and documented filter settings for overcoming clutter is the most powerful and most suitable device for practical use, but it is not the most accurate rangefinder.


Karl

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Matt Markworth
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Re: Nikon 440 Clutter Test

Post by Matt Markworth » Tue Feb 04, 2014 6:57 pm

Karl,

I must congratulate you on this achievement! I am especially impressed by the engineering of your pinhole plate and find your results very interesting.

Your discovery that the Nikon 550 can have an intermediate range in which it cannot effectively penetrate clutter, yet that it can penetrate clutter at a further distance is very intriguing. It would be interesting for other Nikon 550 users to test if they have more success at penetrating clutter by simply moving back to a further distance.

I continue to admire the clutter penetrating ability of the TP200X compared to the TP200. When measuring trees this past weekend, I found myself still relying on the Nikon 440 to get the distance to the base when clutter was an issue.

When I test again, I will create a 100mm pinhole plate to see how far back I can go with the Nikon 440. To effectively test the TP200 again, I think I will need to have more distance between the pinhole plate and the target.

Matt

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