Nikon 440 Clutter Test

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Karlheinz
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Re: Nikon 440 Clutter Test

Post by Karlheinz » Fri Jan 03, 2014 6:08 am

Matt,

I've heard so far, this filter modes in TP200 and Nikon550 are scarcely effective. TP200X has much sharper separation filters, which are also really effective, and the gate can be set in meter increments and there is no minimum distance required.

Therefore for my first tests I will take over your previous arrangement (30' spacing and 2.5'' hole). I want to test with Leica Disto D8 (max. range is specified to 200 m), TP200X and Nikon550. Your new proposal to move the pinhole as a variable is unnecessarily complicated for my first test and with my equipment. I think it would be difficult to refocus the pinhole always accurate, while the positions of instrument and target board stays unchanged, you will need an assisting person. To allow comparability, I therefore appeal to you to carry out first the comparison for TP200 under original conditions.

Deviating from your arrangement I want to use hardboard (uncoated, natural colored, 3mm, 50x50cm) for target and pinhole plate, because the bark of trees and branches in the forest probably also have no high reflectivity.

Karl

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Matt Markworth
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Re: Nikon 440 Clutter Test

Post by Matt Markworth » Fri Jan 03, 2014 8:41 pm

KoutaR wrote:
Matt, had you selected the Farthest Mode for the test?

Kouta
Kouta,

So far, I've only tested my TP200 for distance accuracy in the Standard Mode, but am very interested to see if I can find measurable differences in the modes as I shoot through the artificial clutter in an upcoming test.
Karlheinz wrote:To allow comparability, I therefore appeal to you to carry out first the comparison for TP200 under original conditions.

Deviating from your arrangement I want to use hardboard (uncoated, natural colored, 3mm, 50x50cm) for target and pinhole plate, because the bark of trees and branches in the forest probably also have no high reflectivity.
Karl,

Yes, I can easily set up the original test again and I'll include both the TP200 and Nikon 440 so the conditions are the same for both. I can do that first before I move on to the more extensive test. I also like the idea of using a more natural colored target and pinhole plate to have moderate reflectivity.

Matt

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KoutaR
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Re: Nikon 440 Clutter Test

Post by KoutaR » Sat Jan 04, 2014 3:58 am

Matt Markworth wrote: So far, I've only tested my TP200 for distance accuracy in the Standard Mode, but am very interested to see if I can find measurable differences in the modes as I shoot through the artificial clutter in an upcoming test.
Matt,

I meant did you have your Nikon 440 set to the Farthest Mode in your clutter test? I guess so.

Kouta

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Matt Markworth
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Re: Nikon 440 Clutter Test

Post by Matt Markworth » Sat Jan 04, 2014 9:27 am

Kouta,

Sorry about that, now I understand. The Nikon 440 doesn't have settings for any additional modes. The only functionality of the mode button is switching between yards and meters. I'm not sure if there is an internal routine that gives priority to the farthest distance. I can almost always hit the intended twig as long as I can distinguish it from any clutter, so in practice the unit very consistently gives me the farthest distance.

Matt

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KoutaR
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Re: Nikon 440 Clutter Test

Post by KoutaR » Sat Jan 04, 2014 12:39 pm

Ok, Matt. 550 has the nearest ("1st") and the farthest ("Dst") modes and I thought 440 has, too. I also suspect that 440 tries to select the farthest object. I guess it would otherwise be very difficult to hit with a handheld laser a 2.5'' hole from 240' without touching the edges even if the beam was narrower. If one wanted to measure the actual beam width, the instrument should be possible to set to the nearest mode and one should preferably use a tripod.

Kouta

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Karlheinz
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Re: Nikon 440 Clutter Test

Post by Karlheinz » Sun Jan 05, 2014 7:15 am

Here is my report on the first measurement through a pinhole:
Lochblendentest.jpg
Outside it was uncomfortable today, the wind has tipped over several times my tripod with the pinhole table. But I could gain some experience with my test setup and I can report preliminary results. I wanted to find out the maximum distance between the unit and the pinhole board, up to which measuring through the hole to the target board was still possible.
My setup was:
target board 50 x 50 cm
pinhole board 25 x 25 inch, 2.5 inch diameter pinhole
distance target board - pinhole board: 30 feet


TP200X:
In default setting, without filter functions: up to 7 m
In Farthest Mode: up to 150 m
With combinations of Farthest / Closest and Gate the desired measurement result was to get easier and safer.

Nikon550:
I didn't succeed at any attempt to get a reading.
I want soon to try again, also with a larger pinhole (planned: 10 cm).

Leica DistoD8:
From about 80 meters I could no longer see the point of incidence of the laser beam (looking through the Scope of TruPulse) and lead it. I must examine with less daylight next time.


What still I have to improve:
Pinhole and target plate from the same material and color is poor, because the hole is almost impossible to see. Therefore I have provisionally clamped a blue shopping bag over the target board.
My pinhole plate 63.5 x 63.5 cm (25 in) is a bit small for the TP200X at distances greater than about 120 m, because an increasing portion of the beam passes outside. The size of 1 m x 1 m would be better.


My conclusions:
Further tests are needed. For example I still want to check whether the measured distance differs when I remove the panel with the pinhole out of the beam path.

Nevertheless, it is clear that the TP200X has a much wider beam compared to Nikon440, which has no filter function. But with the filter modes Farthest, Closest, Gate and combination of these, the disadvantage when penetrating clutter is compensated. Presumably it is even significantly superior to a device with a narrow beam without filtering functions.

That to my TP200X is a very nice result, I had hoped for!

Additional, I think that a wider beam can better overcome obstacles like fine Clutter, just like the human eye can. Measurements will succeed even if the beam center is covered. The principle is used in the ultrasonic rangefinders . You do not need so much looking for an absolutely free shooting path as it is needed for a narrow beam and you will faster get results.

Karl
Last edited by Karlheinz on Sun Jan 05, 2014 12:15 pm, edited 1 time in total.

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Matt Markworth
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Re: Nikon 440 Clutter Test

Post by Matt Markworth » Sun Jan 05, 2014 11:03 am

Karl,

Very interesting report. You've shown that the TP200X can hit a target through clutter from a very long distance and that the farthest mode has a big advantage over the default mode when shooting through clutter. I wonder if the TP200 will have a similar result, I must find out!

For the Nikon 550, can you further explain how it performed? I'm unsure if you mean that you hit the target in all attempts or none of the attempts.

I will use your suggestion of changing the color of the target and also use a bigger pinhole plate compared to the one I used when I only tested the Nikon 440. This time I will also set the Nikon 440 on a tripod to make a better comparison.

Matt

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Karlheinz
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Re: Nikon 440 Clutter Test

Post by Karlheinz » Sun Jan 05, 2014 12:00 pm

Matt,

With Nikon 550 A S none of the attempts were successful. I was surprised that it also was not possible to get a reading in the range of 2 to 10 meters in front of the pinhole. However, I had tried it with Nikon only at the end and I felt like it no more desire and wanted to go home. I'll make up for that, and I want to take a pinhole aperture of 10 cm.
I corrected the original text.

Karl

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KoutaR
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Re: Nikon 440 Clutter Test

Post by KoutaR » Sun Jan 05, 2014 12:57 pm

Karlheinz,

You suggested a wide beam with filter is superior to a narrow beam without. If you want to make a top-accurate measurement with a top-accurate instrument, that is true only if you measure the distance and the angle separately, the distance aiming above the top and the angle aiming exactly at the top.

Kouta

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Karlheinz
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Re: Nikon 440 Clutter Test

Post by Karlheinz » Mon Jan 06, 2014 9:04 am

KoutaR wrote:You suggested a wide beam with filter is superior to a narrow beam without.
My statement refers to penetrating clutter!
Will wrote: (related to Nikon 440):
Now, if someone would put that laser into a instrument with the built in clinometer we would be golden.
This statement I agree, when accuracy is mattered!

It is undisputed: If no clutter is in the way, you can achieve the most accurate results with a narrow beam. With the width of the beam also grows the error described by Kouta when measuring to the treetop. However, a tight punctiform beam has the disadvantage that targeting will be a challenge, especially in windy conditions. The actual beam width of any instrument always will be a compromise. The TP200X is not optimized for accuracy in the distance range of most interest to us (<120 m), but rather on practicality in everyday use. You can achieve good results with little effort, even if clutter is in the way, no other instrument can do that as well. For me that is a notable advance in dendrometry.

Karl

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