Lets say you are 10 yards up in a tree. The range finder selects a deer that is 20 yards away. I am not sure what the the exact distance is but let us say that from the base of the tree to the deer it is only 15 yards. From 10 yards up in the air do you aim for the 20 yards what the range finder is showing or the 15 yards which is the actual distance from the base of the tree to the deer. Should I aim for 15 or 20? Need help on this. My physics and trig are a little rusty.
Thanks,
Also with a name Vector this looks very bad. Vector was the name of the boat I had not that I remeber my physics or trig..

You use the distance from the base of the tree to the deer. That' s something I' ve always wondered, why don' t rangefinder manufacturers build in a compensator for this. You could push a button to " calibrate stand height" , range the ground under your stand, and a chip could easily do the calculation to show you that actual level ground yardage to the deer instead of a longer readout...

If you are 20 ft up a tree and your target is 20 yds away - the difference between the base of tree measurement and stand measurement is " 1 yard" .

It doesn' t make a hill of beans.

I always range from the stand - any slight extra length is cancelled out by the arrows change from perpendicular to gravity. It travels a bit longer - but it drops a bit less because of this angle.

Just bend at the waist, practice from that height - and range from wherever you feel like it

FWIW, if you are 10 yards up(30 feet) and the distance from you to the deer is 20 yards(60 feet) then the distance from the base of the tree to the deer is 17.32 yards(51.96 feet). A difference of 2.68 yards(8.04 feet). At 20 feet up things look a lot better for shot angles at closer ranges....just something to think about.

Rack, with your set up, I agree...

But if someone is flinging logs and the distance goes out to 30 yards, I could see it making a difference.

Here' s an article that seems to do a good job of explaining it. You may have to select the article from a list, it' s titled how to judge distance from a tree or something like that...

http://www.archery.net/articles/index.shtml

Practice,,,Practice,,,,Practice....I am lucky in the fact that I have a Cabin in the Mountains. I have tree stands that I practice from on different yardages. I find that shooting from a tree stand I have to hold a little high. The Arrow seems to drop faster when shooting from a tree stand. This is just my own experience, but I have been doing this for over 30 years.

Vector, I shoot whatever the rangefinder tells me. If I range from my stand and it says that it is 27 yards then thats what I shoot it for. With most setups I feel the yardage difference will be small enough that it won' t make much difference.

It would be great if that was reality. However, it is not. Setups are too individual to fall into a common category of " With most setups." Best know how your gun shoots at various distances to the max you intend to shoot.

Additionally, I would calibrate your rangfinder distance being indicated with actual measured yardage so you know that an indication of 20 yards (example) is actually 17 yards or otherwise.

When I use my rangefinder I usually take my reading at the same height as I am.(at least close) So if the tree is in front of me, I don' t shoot the base, I' ll shoot the rangefinder at about my stand height up on the tree. That thing is really handy, but practice is still an absolulte must.

Good Luck!

Same here cloud 9.