Rangefinder Slope

[MSB]

So I was thinking about how slope rangefinders work - from what I know they measure the distance to the pin and measure the angle of the laser, and using some formula they arrive at the slope adjusted difference. Does anybody know that formula?

[h_baden]

Google: The Pythagorean Theorem

Also, we know that all angles in a triangle added together is 180 degrees...

[MSB]

h_baden, I don't believe that's correct - consider a 150 yard shot to a 10 yard uphill pin.

 

150²+10²=22,600

 

22,600 ^.5 = 150.33

 

We all know that a 10 yard uphill shot from 150 plays a lot more than 150.33.

[Stetson]

Google: The Pythagorean Theorem

Also, we know that all angles in a triangle added together is 180 degrees...

 

This wouldn't be accurate. 150 would be the hypotenuse in this scenario because it is the linear distance from the rangefinder to the flagstick, because of this a 90* angle cannot be used and the theorem is irrelevant.

 

As for the actual calculation I thought it over and decided that I could not find a formula that is accurate universally, I am sure the manufacturers have been able to crack this code though. The problem I ran into is that elevation change makes a bigger difference at longer distances, because a PW descends at a steeper angle than a 5 iron so it would have to be on some sort of non-linear curve to account for this.

 

But all this physics is not my specialty

[b.helts]

SOHCAHTOA

[taporsnap17]

SOHCAHTOA

 

Would be the same as a Pythagoras wouldn't it?

 

The distance wouldn't change as such. If you laser it, 150 yards and 150 yards straight line, whether it's straight ahead or up or down hill. I'm assuming each manufacturer are using a formula to work out the "play" distance. I'm thinking it's probably proprietary formula. That way they can hope to cliam being more accurate than another manufacturers'

[b.helts]

They are definitely related but the Pythagorean Theorem isn't needed to get the adjusted yardage. But once the adjusted yardage is calculate you could use Pythagorean Theorum to determine actual change in alititude.

[SadTrombone]

[Stetson]

Just to confirm, a 20* incline for 150 yards is equal to 160? Call me crazy but I would think that is not enough

[SadTrombone]

Just to confirm, a 20* incline for 150 yards is equal to 160? Call me crazy but I would think that is not enough

 

Couldn't tell you, I never took trig. Found the picture with a google search and it seemed reasonable. I just look at the number in the window and then hit it 10 yards short of that.