What is the Cartesian sign convention for microscope and telescope distances?

[Suyash Singh]

Homework Statement

Cartesian sign convetion for microscope,compound microscope and telescope.

Homework Equations

distances in the direction of incident ray are negative and thsoe along it are positive.
all distances are measured from pole of lens or mirror.

The Attempt at a Solution

1.FOR COMPOUND MICROSCOPE
eyepiece:
Fe is -
Ue is -
Ve is -
objective:
Fo is +
Vo is +
Uo is -
2.FOR MICROSCOPE
Vo is +
Uo is -
Fo is +
3.TELESCOPE
Objective:
Fo is +
Vo is +
Uo is -
eyepiece:
Fe is -
Ue is -
Ve is -
Am i correct?
i am so confused about this sign thing.

 

[jedishrfu]

This article describes it in some detail along with advantages and disadvantages

http://www.practicalphysics.org/longitudinal-lens-formula-and-sign-conventions.html