a) The position of the eye is located between the base and the top of the stem, but the direction is not parallel to the viewfinder flat / directions viewfinder decreased (Figure 29).
From the images could be obtained high trees formula, namely:
T = (t1 + t2)
T = (Sn x tangent α) + (Sn x tangent β)
T = Sn x (tangent to tangent α + β)
Figure 29. The basic formula of high based on the position (4)
Information :
T = total tree height (m)
t1 = BC tree height (m)
t2 = AB tree height (m)
Sn = distance between the viewfinder flat with trees (m)
α = angle formed when shooting treetops (m)
β = angle formed when aiming the base of the tree (m)
b) The position of the eye is higher than the top of the stem / directions viewfinder decreased (Figure 30)
Figure 30. The basic formula of high based on the position (5)
From the images could be obtained high trees formula, namely:
T = (t2 – t1)
T = (Sn x tangent β) – (Sn x tangent α)
T = Sn x (β tangent – tangent α)
Information :
T = total tree height (m)
t1 = height BC (m)
t2 = height AB (m)
Sn = distance between the viewfinder flat with trees (m)
α = angle formed when shooting treetops (m)
β = angle formed when aiming the base of the tree (m)
Noting fifth high above the basic formula, it turns out there are three groups of tall trees formula, namely:
a) T = Sn x (tangent to tangent α + β)
This formula is used when the position of the sight and the tree stands at the position (1), position (2), and position (4). Why can occur using the same formula? It turned out that the position of the position (1), position (2), and position (4), eye sight is still located between the base and the top of the stem at the time of measurement of tree height.
b) T = Sn x (α tangent – tangent β)
This formula is used when the position of the sight and the tree stands at the position (3), the position of the eyes is lower than the base of the stem (viewfinder ascending direction).
c) T = Sn x (β tangent – tangent α)
This formula is used when the position of the sight and the tree stands at the position (5), the position of the eyes is higher than the top of the stem (aimed the downhill).
Things to remember!
a) The three high above formula applies to the terms of the angle formed value is always a positive value, either you aimed up or down.
b) Directions division scale starts from the position of the flat (flat areas when shooting at eye level) is worth 00, then to declare you aimed upward angle values are marked + (positive) and the value of the angle to the direction shutter down marked – (negative) , So based on the direction of the viewfinder, then the three basic formula above can be summarized into one high formula, namely:
T = Sn x (α tangent – tangent β)
c) the value of α or β may be positive or negative, depending on the position you aimed.