laser range finder for tree height - cheap 1?

[Kevin]

When sighting on the tool, do you use the tops of the blue open triangles, like the one above Tim Curds signature, or the tip of the points on the plastic cross?  

Do you change the angle of the tool to get the tree within the marks or are you suppose to keep the tool level at all times.

I have been doing some testing on shorter objects and the height/distance does not match up, so I figure it is probably user error.

Keep the tool level and move forward or back up.
Sight from tip of each end of the plastic.

[SwampDonkey]

Thanks for the feedback Tillaway, I'm going to forward your concerns, and mine, to the dealer.

cheers

[rebocardo]

Well, I am still working on this and I am going to buy a better tool then the $12 one I bought. I am probably not getting the hang of it with my eyeglasses or something on because it is inaccurate at least on the short stuff.

My question is how to figure height from angles if I buy a range finder. northern toolhttps://forestryforum.com/board/index.php?action=position"> Note:Please read the Forestry Forum's postion on this company has the Bushnell for $199.00

If I buy a range finder and measure to the top of the tree (A=150?) and to the bottom of the tree (B=100?) and I am measuring from six feet off the ground, how do I figure the tree height (C?).

[farmerdoug]

It is a simple formula.

A squared + B squared = C squared
so
C = Square root of(A*A+B*B)

Is that clear as mud.  I do not know how to show it normally on a keybroad so maybe somone else can do that.
As far as height off ground just add that to the total, but this only works on right triangles so you have to be at the same level as the tree you are measuring.
If you still need help I will try to help.

[Larry]

Got me cornfused so I'll put it the way I can understand it. ???
   
A=height
B=run (distance from you to tree base)
C=hypotenuse

C (squared) - B (squared) = A(squared)   

As Doug mentioned it is only good for right triangles.  I wasn't very good in math so maybe somebody has a better answer...or maybe I'm really confused.

A far easier and cheaper way is to hold a stick in your hand at arms length vertically.  Sight with your eye so the top of the stick aligns with the top of the tree.  Bottom of stick aligns with your thumb and tree base. Rotate stick to horizontal and mark the spot where top of stick intersects ground.  Bottom of stick, tree bottom, and thumb are all aligned.  It is more accurate than it sounds.

If you still want to go with the lazer thing I got the Bushnell Lazer Pro 800 when they first came out and it has been reliable and accurate.

[SwampDonkey]

Well, with a Suunto clinometer... percent scale

{top shot - (bottom shot)}/100 * horizontal distance from tree centre, then add 1.3 meters if bottom shot was taken at breast height

chain scale 1 : 66

{top shot - (bottom shot}/66 and stand 66 feet or 20 meters from the tree centre, then add 4.1 feet if bottom shot was taken at breast height

With a Laser Hypsometer.....
Point at the tree in approximately horizontal angle and press the button until beep.
   
Then point at the top of the tree and press button until it beeps. This is the measurement of the angle up to the top.
   
Point at the root of the tree and press the button until it beeps. This is the angle down to the root of the tree.

Then the built in microprocessor calculates the height from the two angles and the distance to the tree. Accuracy is about +- 0,5 m .

[KiwiCharlie]

Hi,
I can add a vote for the Suunto clinometers. Depending on model, can do degrees and percent.  Fairly inexpensive too (200NZ, around 120-140US?).  Silva do a slightly cheaper Clinomaster, but I havent used that one.
Just found a link - http://store.karstsports.com/15027.html
Cheers
Charlie.

[rebocardo]

I just wanted to thank everyone for their help, even though it was a while ago. I bought a Brunton CM360LA (percent and degrees) from Baileys about a week ago for a specific job. I was going for the $80 model, but, the guy at Baileys asked me if I really wanted it since he had never sold one and it was metric and just degrees. So, I opted for the more expensive one after he went and asked someone about it.

I practiced in my own yard first, then went to the customer's site. Using it, it was spot on for height and the tree was within 1ft (86) of the estimated 85 I got using the clinometer. Originally I thought the tree was no more then 80 feet tall. Glad I knew the exact height and dropped it between two houses instead of towards the power lines 90 feet away. 4 feet is to close of a shave  ;)

Just thank you again, I saved $300+ not buying the fancy electronic range finding one, though it is always an option for a future purchase when I win the lottery  :D

Basically you just add the top % (a) and bottom % (b)

A+B=C %

C% x distance from tree = height

I noted what people said about the 100 degrees, you get a much more accurate reading the further away you are, so I stand at the edge of the property on as level a spot as possible.

Happy with purchase  8)

[SwampDonkey]

Well, all I can say is...'I told ya so' :D :D :D

[rebocardo]

Thank you$ for telling me  ;)