My Rangefinders TruPulse200X, Leica and Nikon

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

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Karlheinz
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My Rangefinders TruPulse200X, Leica and Nikon

Post by Karlheinz » Sat Dec 07, 2013 9:07 am

Hi measuring Folks,

Now that I am measuring the height of tall European trees for more than two years, I would like to report about my experiences with my instruments. I have the following rangefinders with built-in inclinometers:

Leica Disto D8 (bought in July 2011 )
Nikon550AS (bought in Sept. 2012 )
TruPulse200X (bought in Nov. 2013 )

With the Leica I was not satisfied because sine measurement to the top of tall trees was successful only under particularly favorable conditions (no wind, twilight). With the Nikon finally I was no longer satisfied, because the inclinometer fidgets so much, the measurement result is too dependent on experience, skill and a steady hand of the measurer.

Now for a few days the TruPulse200X is new to the market and I was able to get one of the first units (firmware version 1466), thanks to good relations to the German distributor. Main reason for buying this expensive device was the expectation of being able to measure treetops more easily and accurately than before.



1) My first, preliminary report on experience with TruPulse200X
TruPulse-on-tripod.jpg
Exactly these above-mentioned expectation does the TP200X fulfill! After my first test experience, I can say that the measurements are accurate and reproducible, but concrete comparison measurements with Leica set as the reference are still pending. Distance is displayed in increments of 1 cm and inclination in steps of 0.1 ° (Leica shows on in steps of 1 mm and 0.05 °). The Filter Modes "Closest", "Farthest" and "Gate" work effective. Hiding unwanted reflections when measuring through cluttered environments succeeds in surprising many situations where my other devices have long ceased. The effort to search for a reasonably free measuring corridor should thus be much lower in the future. Whether or to what extent the accuracy decreases when measuring with filter functions through clutter, I can’t judge yet.

The automatic adjustment of the laser at the distance and the reflective qualities of the target works well and easily. According to the manual the TP200X is specified for a measurement range of 0 m to 2,500 m. Such large range is not available with the other devices. I was able to test that the laser actually does not need any minimum distance, it measures from just a few centimeters. - But this specification of the manufacturer is misleading! The built-in scope can’t focus at close range below about 10 meters, it has no setting option for distance. The ring on the eyepiece is intended to focus the in-scope display. Thus, precise sighting and the differentiation between closely-spaced small targets in this distance range is no longer possible. Relying on this specification I had expected, I can use the TP200X in tape-drop actions for measuring the rest to the top. After climbing to the crown of a beech I wanted to scan their tips. But whether it still makes sense with the washed-out target image is doubtful.

The scope of the TP200X has in contrast to Nikon a high-quality optics, the clear view through the scope is less tiring and can be used also in twilight. Also for digiscoping the scope of TP200X is well suited. LTI offers an iPhone holder, but totally overpriced with $ 300. I 'll probably try it with a self-construction, where I can flip a compact camera in front of the eyepiece. I think that in future we will see more target photos taken through the eyepiece of a scope.

The laser of the TP200X is an infrared pulse laser. About beam width you will not find any information in the technical specifications. Derrick Reish from LTI did not respond to my emails. The German distributor Breithaupt told on request: The laser spot of the TP200X is an ellipse, at 50 m distance 10 cm wide and 7.5 cm high. Thus, the beam is about three times wider than on the Leica. The beam width is always a compromise. With a wide beam you do not need to aim so accurately, but it may not select small targets separately. I prefer a narrow beam like the Leica has it.


I do not want to conceal: The TP200X leaves an ancient impression on me. The development of modern electronic equipment from computer and smartphone technology seems to have gone completely past at the TruPulse. A much more modern impression makes, for example, the new Leica Disto D810 with touch-screen display, where menus, measured values and target photos are clearly displayed and stored in the device.
The TP200X has no display on the housing. Only when looking through the scope you will see an illuminable, rough structured internal display. It shows the crosshair for envisaging the target and various icons and after the measurement one each measured or calculated value. The four belonging together values of a measurement point can’t be represented together at same time. They can only be displayed stepwise singly one after by pressing an arrow key.

After 90 seconds all values will be deleted. I found no way to stop or to delay this expiration. If you want to write down all four values, you need quickly and cleverly play with your eyes switching between eyepiece and book and your hands switching between button, book and pen. I hope that this problem can be solved via firmware update. But that is not so easy, the unit must be returned.

I have not found a solution as I can document this four values of one measurement point. When copying by hand, errors can creep in, this is no documentation. Should I take, for example, four individual photos through the eyepiece after each measurement? With Leica and Nikon I can do it by taking one photo of the external display, with Leica also later by retrieval from memory. Nevertheless, a device of this price range should offer more! The transmission of a measured value via Bluetooth or serial port is apparently possible only during measurement. I have not tested this, because I would have to carry and set up a corresponding receiving device out in the woods. That would be another story. Why doesn't LTI install a memory chip so that I can retrieve the data on my PC at home later?

The operation principle of TP200X with the four push-buttons is learned fast. However, I have continuously difficulties in finding the keys with my fingers without visual control. I wished for better palpable keys and I think the arrow keys are ergonomically unfavorably arranged. Probable the designers have prevailed over the engineers. The enclosed neck strap I would not trust, I fear the expensive device could be pulled out from the buckle.

The manual is currently available only in the English version as a pdf file. Here, as usual, the three-point measurement method is described again as the standard method for tree height measurement. To the inherently much higher accuracy of the two point sine measuring method isn't pointed out. So that once again is preprogrammed that crowds of foresters in spite of precise measuring instruments again will produce only second-class readings. They have learned and internalized that the forest-customary measurement towards treetop only needs the angle. In the past when good devices for sine measurements to treetop not were available, the three-point measurement had its authorisation. At least now with the abilities of TP200X the situation has changed. But apparently LTI has not the courage to enlighten this large group of their customers in the forestry and timber industry, it might be understood as an unreasonable instruction.


It would be interesting to compare with the previous model TP200 and whether the significant additional expenditure for the TP200X are worthwhile. On this topic someone should speak who knows both devices.



2) My experiences with the Leica Disto D8
Leica-on-tripod.jpg
The Leica Disto D8 measures with a tightly focused red laser beam (6 cm in diameter per 100 m), which is visible as a red point when hitting an object. With visual contact to this red point of impact you can steer the beam accurately at a target. Perhaps field glasses will render good services here. Thus even thin twigs can be targeted and measured selectively to the millimeter. This is more accurate than aiming by the crosshairs of the TP200X. Alternatively you can use the built-in digital aim camera with 4x-zoom for targeting.

If one assumes the specifications of the manufacturers, the Leica measures by a factor of 40 more accurate than the TP200X, especially in the near distance range up to 10 meters. By comparing measurements with steel measuring tape I was able to convince me that this high accuracy in the mm range really is achieved. Even with larger distances to good reflecting targets each repetition of the measurement leads to almost identical values. From such a reproducibility of the measured values Nikon owners can only dream about!

The display shows the distance in meters to three decimal places (mm). For better clarity and because I do not need the millimeters when measuring trees, in the options menu I have reduced the display by one decimal place to show only the centimeters (cm).

For reasons of eye safety the power and thus the range is limited. A measurement to treetop succeeds in bright daylight to about 20 m, at twilight I had success up to 80 m. But with such weak targets at the limit of what is possible, the measurement accuracy decreases. For reflective targets in shaded woods the measuring range is about 200 m. The photo shows the measurement setup with Leica and rifle scope to the top of Bavaria's highest tree, which is a Douglas Fir.
Sine-measuring the treetop of Bavarias tallest tree, with Leica Disto D8 and rifle scope, with no wind and at twilight <br />&lt;http://www.monumentaltrees.com/de/deu/bayern/aschaffenburg/6889_imkaltengrundabteilunglangruck/13867/&gt;
Sine-measuring the treetop of Bavarias tallest tree, with Leica Disto D8 and rifle scope, with no wind and at twilight
<http://www.monumentaltrees.com/de/deu/bayern/aschaffenburg/6889_imkaltengrundabteilunglangruck/13867/>
3) My experiences with the Nikon550AS
Nikon-on-tripod.jpg
The Nikon measures like the TruPulse with an invisible pulse laser. Beside the display in the eyepiece it has yet an additional display outside of the housing, where all values of a measurement point are clearly displayed. It has no internal memory for permanent storage of measured values. The measured values fall irrevocably when turning off the device. This occurs automatically when more than 30 seconds no key has been pressed. It is specified as a handheld device and has no tripod mount. There is no specific measurement accuracy guaranteed. The height is displayed in increments of 20 cm. This is compared to the other devices just little and particularly unsatisfactory at close range. Below 10 m measurement is not possible, the range is up to 500 m. The more expensive Nikon Forestry Pro additionally masters the three-point measurement program, it brings in my opinion no rewarding benefits. Higher measurement accuracy do I get by mounting on tripod using a self-made rubber mount.



4) Summary

The Leica convinces by unsurpassed accuracy at short to medium distances. Due to its limited range, it is as the only instrument for tree height measurement less advisable. The TruPulse has its strengths at medium to long distances and under difficult conditions. Nikon is the affordable entry-level device.

As the great difference in price can be expected, the TruPulse200X is the Nikon clearly superior in all measurement disciplines. Anyone who previously has struggled with the Nikon in dense forest to find a measurement position with reasonably clear line to the treetop, will be surprised now how easily a measurement with the TP200X succeeds. The filter functions to penetrate clutter are convincing. You can combine the filter modes Farthest and Gate, that I found is the best to penetrate clutter. I think this is a step forward in measuring technology. However, I do not know how well the previous TP200 already could handle the job with the filter mode Farthest. Somebody who owns both TruPulses should comment. On the other hand, you should also not expect any miracles from the filter functions, somewhere there are limits.

At Nikon I stated the tolerance range when measuring a tall tree with about 1% (up to 2%). At TP200X I hope to be able to reduce the tolerance down to +/- 0.2%. Whether this assessment is correct, remains to be seen in future. Comparative measurements with other instruments or other measurement methods are still required. Our most precise so far measured values we believe to have achieved with the tape-drop method, there we estimate the tolerance also at about +/- 0.2%.


The ability to measure the distance to the treetop directly, easily and reliably, even under difficult conditions, and with high measurement accuracy, that's the really big plus point of the TP200X. None of the other devices that I know can match that. I wouldn't like to do without the TP200X anymore! There I have to accept its old-fashioned inconvenience and weakness at close range.

For measurements in trunk and forest floor areas, in particular for the calibration of intermediate reference points and at short distances the Leica Disto D8 (or D810) is by far the most accurate and my preferred instrument. In future will appear whether the exactness of the TP200X in the close and medium distance range is sufficient for me, to do without carrying along the Leica as second equipment.

In order to compare the measured values of Leica and TruPulse, I will build me a mounting plate where I can mount both devices side by side on a tripod. And I can use the scope of TP200X as a tool for the Leica to align the red laser beam on the target. In order to increase the measurement accuracy of the TP200X, I will initiate the measurement process without shaking or wobbling by using a remote trigger cable. With the Leica I start the measurement process by using the timer.

As a future development, I would like to see a modern device with a large display, a watch chip and a GPS chip, camera and data storage that combines the two lasers and the capabilities of both devices in one housing. The measured values must be documented with photo finish, time and GPS stamp. Both laser beams must be accurately calibrated to the same direction. Then I could use the red laser as a targeting device for the invisible pulse laser and increase its measurement accuracy

The Nikon is now dispensable for me. Nevertheless, I want to keep the Nikon for use as an "always have with me" device for quick first measurements and as a spare device. The Nikon will continue to keep its importance as a reasonably priced entry-level device. With its modest display accuracy, it puts me never ceases to amaze how accurate measuring results trained users can achieve with it. Still, I could imagine that at the European tree measurers the current dominance of Nikon equipment is ending.

Important for accurate measurement is: It must not wobble during the measurement. This requires a stable high tripod with a video-pan-tilt head that provides smooth, jerk-free guiding. Also touching the case and pressing the release button with your hand are disturbing factors, that you can turn off by using a self-timer or a remote release cable.

Bob, Robert T. Leverett from NTS, has announced to publish field tests about the TP200X http://www.ents-bbs.org/viewtopic.php?f=235&t=5517 , I'm looking forward to the results.

Furthermore, I wish you a lot of fun and success with tree measuring!

Karlheinz


(This article is published at http://www.monumentaltrees.com/ and http://www.ents-bbs.org/ )

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Will Blozan
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Re: My Rangefinders TruPulse200X, Leica and Nikon

Post by Will Blozan » Sat Dec 07, 2013 11:40 am

Karlheinz,

A most excellent report! I was fortunate to have used the 200X for a few brief hours and was likewise impressed by the penetration and gate function. I agree with your other comments and find the near distance blur very annoying (I am now starting to use the TP 360 and have the same issues). But as an overall "gets most things done well" instrument it would get my vote. I just simply can't afford one right now!

Thank you for your detailed narrative and comparative exercise.

Will

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Larry Tucei
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Re: My Rangefinders TruPulse200X, Leica and Nikon

Post by Larry Tucei » Sat Dec 07, 2013 12:07 pm

Karl, I second what Will said. I just got a TruPulse 200 and really have been enjoying it. I use it and my Prostaff 440 because of the narrow beam it can shoot through tight spots where the TruPulse cannot. I'm sure Bob and others will weigh in on this topic and be able to describe in detail what you are asking. Great comparison of instruments. Larry

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DougBidlack
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Re: My Rangefinders TruPulse200X, Leica and Nikon

Post by DougBidlack » Sat Dec 07, 2013 1:21 pm

Karlheinz,

thank you very much for that excellent report! I hope to receive the 200x sometime this month. I hope to be able to compare the 200x to the Nikon 440 + clinometer to 50', telescoping measuring pole. These will be smaller trees that I am growing but I think it will be a good first comparison for me.

Did you calibrate the Trupulse 200x? If so, how did you calibrate it?

Doug

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Don
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Re: My Rangefinders TruPulse200X, Leica and Nikon

Post by Don » Sat Dec 07, 2013 4:27 pm

Karl-
Very informative report!
Towards a more perfect all-in-one device, I have been looking at a software application for the iPhone called Theodolite.
On the positive side:
1)it uses accelerometers and gyros to take vertical angle measurements
2)measures azimuth
3)assigns real world coordinates (I believe they're cell phone-based)
4)measures lean
5)creates a log of data collected
6)has email communication (through iPhone), that can transmit log, images to another site for storage
7)has digital image capture, as well as video (through iPhone)
Theodolite App image
Theodolite App image
On the negative side:
1)its digital image resolution is limited (iPhone 4, less so with iPhone 5S with its zoom)
2)iPhone needs case or other mechanism to be attached to a tripod (Belkin has hardware to attach to tripod, and another device to remote control shutter.

To increase digital image resolution, I searched the internet and discovered that Sony had just released a new lens (QX10, which has been "extricated" from a Sony DSC-WX200 camera. For example see

http://www.photographyblog.com/reviews/ ... 10_review/ or search on QX10)

The advantage here is that the lens attaches to iPhone (as well as a number of other Smartphones), communicates through WiFi with iPhone transmitting image and associated data either to memory chip in lens, or to iPhone (new iPhone 5S has 64 Mb memory). The best part? The QX10 lens is 10 power (has the 35mm camera equivalent of a 25mm to 250mm zoom lens).
The down side is that the software program Sony uses to communicate between their lens and the iPhone is a bit, hmmm, proprietary and ineffective so far. A number of software solutions are expected, but not yet come forward.

I've been in contact with the Theodolite's developer (Craig Hunter, Hunter Research and Technology, LLC) who has shown interest in my efforts to pair the Sony lens with the iPhone and Theodolite app. It's been more difficult to make headway with Sony, although they have released an API (http://camera.developer.sony.com/) for those who are capable with software development and integration.

I do think it's promising, and hope that contacts such as mine, and yours (if you're interested) may alert them to our effort.

Your photos have revived my interest in pairing my iPhone with a 5x rifle scope I have, for a targeting mechanism for another iPhone App called Clinometer (another accelerometer-based vertical-measure software).

-Don
Don Bertolette - President/Moderator, WNTS BBS
Restoration Forester (Retired)
Science Center
Grand Canyon National Park

BJCP Apprentice Beer Judge

View my Alaska Big Tree List Webpage at:
http://www.akbigtreelist.org

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dbhguru
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Re: My Rangefinders TruPulse200X, Leica and Nikon

Post by dbhguru » Sun Dec 08, 2013 8:18 am

Karl,

Superb report. We all are indebted to you. I'm still waiting on hearing from LTI. Can't understand what is holding things up. Maybe they regard me as a sure sale and feel no pressure in filling the order. Hmmmm.

If they will now work on a model that adds the digital compass and also offers a reticle, then we'd have a soup-to-nuts instrument. Price? I imagine those features would push the price to over $2,000. Ouch!

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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Karlheinz
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Re: My Rangefinders TruPulse200X, Leica and Nikon

Post by Karlheinz » Sun Dec 08, 2013 8:21 am

For the TP200X I want to say in addition:

With the TP200X measuring the treetop has become easier, you no longer need so much effort into looking for a free line, even untrained people more quickly will achieve good sine measurement results now. Fans, however, who are willing to spend every effort for optimum measurement results, prefer instruments with narrow focused beam (such as Leica Disto or Nikon440) and thus may come to the best results.


Doug,

with calibrating the TP200X I have not yet employed. In the manual I read only: Aligning the tilt sensor can not be realigned in the field, the instrument must return to the factory.


Karl

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DougBidlack
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Re: My Rangefinders TruPulse200X, Leica and Nikon

Post by DougBidlack » Sun Dec 08, 2013 9:54 am

Karl,

I was just wondered if you compared the TP200X to something that you know is very accurate such as a steel tape or perhaps a very accurate laser that you have already tested. Then you can compare the TP200X to this standard. Then, if the TP200X reads 100.1m at 100m and 200.2m at 200m you can come up with an easy correction factor. This means that you couldn't use the automated method for measuring tree height as you would need to record height and angle to base as well as height and angle to top. This would be cumbersome but it would be more accurate if the TP200X is a little off.

Doug

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Karlheinz
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Re: My Rangefinders TruPulse200X, Leica and Nikon

Post by Karlheinz » Sun Dec 08, 2013 5:22 pm

Doug,

So then you mean by "calibrating" only the calibration of the rangefinder without consideration of the inclinometer.
I will, as announced, first build a mounting plate where I can mount TP200X and Leica Disto side by side on a tripod.
Then I am able to calibrate the TP200X by using the Leica.

Maybe you do not know or not believe the accuracy of the Leica Disto D8, that is in fact comparable to that of a steel measuring tape.
The manufacturer Leica announces in the manual this technical datas:

Distance measurements:
Measuring accuracy up to 30 m typically: ± 1.0 mm*
*Measuring accuracy may deteriorate by approx. ± 0.1 mm/m for distances above 30 m

Accordingly, the maximum measurement error is at 100 m less than 2 cm.

As I have already written, I need the TP200X for the measurement to the treetop (and in cluttered environments).
For accurate measurements at close range and near the ground to about 100 m, the Leica Disto is much better suited.

Karl

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DougBidlack
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Re: My Rangefinders TruPulse200X, Leica and Nikon

Post by DougBidlack » Sun Dec 08, 2013 10:59 pm

Karl,

yes, that is correct, I just meant calibration of distance measurement. I'm not certain how to calibrate the inclinometer. It sounds like the Leica Disto D8 is quite accurate and should be good for calibrating the TP200X. I'm sure we're all very interested to see how the TP200X compares to tape drops or other direct measurements such as measuring poles. I'll be looking forward to your tests as well as Bob's.

Doug

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