OPH141 LESSON 14, Resultant prism.

Answers to resultant prism problems

Steps to using the table to solve resultant prism problems.

Decide what the horizontal and vertical amounts are, and what quadrant the answer will be in.
Find the appropriate row (vertical - down the side) and column (horizontal - across the top).
Find the prism amount and axis from the intersection of the row and column.
Determine whether the meridian is equal to the axis or 180 - the axis.

In Q II and Q IV subtract the axis from 180. In Q I and Q III keep the axis as is.
For 360 notation, in Q III and IV add 180 to the result of stpe 3.

OD 5.5BU & 1.5BI

5.5 is horizontal and 1.5 is vertical. This is Q I.
5.7 and 75 degrees are the entries in the table(s) at the intersection of the 5.5 row and the 1.5 column.
In Q I the axis is the meridian.

5.7 BU&I @ 075

5.7 @ 075.

OS 1.5BU & 3.0BI

3.0 is horizontal and 1.5 is vertical. This is Q II.
3.4 and 27 degrees are the entries in the table(s) at the intersection of the 3.0 row and the 1.5 column.
For Q II the meridian is 180 - the axis, or 180 - 27 = 153.

3.4 BU&I @ 153

3.7 @ 153.

OD 3.0BD & 2.25BI

2.25 is horizontal and 3.0 is vertical. This is Q IV.
3.8 and 53 degrees are the entries in the table(s) at the intersection of the 3.0 row and the 2.25 column.
For Q IV the meridian is 180 - the axis, or 180 - 53 = 127.

3.8 BD&I @ 127

3.8 @ 307.

OS 2.25BD & 4.0BI

4.0 is horizontal and 2.25 is vertical. This is Q III.
4.6 and 29 degrees are the entries in the table(s) at the intersection of the 2.25 row and the 4.0 column.
In Q III the axis is the meridian. For 360 notation the meridian is 180 + 29 = 209.

4.6 BD&I @ 029

4.6 @ 209.

OD 4.0BD & 4.5BO

4.5 is horizontal and 4.0 is vertical. This is Q III.
6.0 and 42 degrees are the entries in the table(s) at the intersection of the 4.0 row and the 4.5 column.
In Q III the axis is the meridian. For 360 notation we add 180 degrees, for 222.

6.0 BD&O @ 042

6.0 @ 222.

OS 5.0BD & 2.75BO

2.75 is horizontal and 5.0 is vertical. This is Q IV.
5.7 and 61 degrees are the entries in the table(s) at the intersection of the 5.0 row and the 2.75 column.
For Q IV the meridian is 180 - the axis, or 180 - 61 = 119.

5.7 BD&O @ 119

5.7 @ 299.

OD2.75BU & 0.5BO

0.5 is horizontal and 2.75 is vertical. This is Q II.
2.8 and 80 degrees are the entries in the table(s) at the intersection of the 0.5 row and the 2.75 column.
For Q II the meridian is 180 - the axis, or 180 - 80 = 100.

2.8 BU&O @ 100

2.8 @ 100.

OS 0.5BU & 5.5BO

5.5 is horizontal and 0.5 is vertical. This is Q I.
5.5 and 5 degrees are the entries in the table(s) at the intersection of the 0.5 row and the 5.5 column.
In Q I the axis is the meridian.

5.5 BU&O @ 005

5.5 @ 005.

OD 3.5BI & 3.5BU

3.5 is horizontal and 3.5 is vertical. This is Q I.
4.9 (or 5.0, depending on which table you use) and 45 degrees are the entries in the table(s) at the intersection of the 3.5 row and the 3.5 column.
In Q I the axis is the meridian.

4.9 BU&I @ 045

4.9 @ 045.

OS 3.0BI & 4.0BD

3.0 is horizontal and 4.0 is vertical. This is Q III.
5.0 and 53 degrees are the entries in the table(s) at the intersection of the 4.0 row and the 3.0 column.
In Q III the axis is the meridian.

5.0 BD&I @ 053

5.0 @ 233.

OS 4.0BO & 1.0BD

4.0 is horizontal and 1.0 is vertical. This is Q IV.
4.1 and 14 degrees are the entries in the table(s) at the intersection of the 1.0 row and the 4.0 column.
For Q IV the meridian is 180 - the axis, or 180 - 14 = 166.

4.1 BD&O @ 166

4.1 @ 346.

OD 1.0BO & 1.5BU

1.0 is horizontal and 1.5 is vertical. This is Q II.
1.8 and 56 degrees are the entries in the table(s) at the intersection of the 1.5 row and the 1.0 column.
For Q II the meridian is 180 - the axis, or 180 - 56 = 124. .

1.8 BU&O @ 124

1.8 @ 124.

OD 1.5BU

1.5 BU @ 090

OS 3.0BI

3.0 BI @ 180.

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