Ray Optics : Sign Convention

I Heard That IIT Examiners Are Looking For The New International Sign Conventions To Be Used In Solving Problems relating To Optics.
What Is The Sign Conventions To Be Used In Solving Problems Regarding REFRACTION AT SPHERICAL SURFACES ?

Re: Ray Optics : Sign Convention

It does not matter which sign convention you use ur answer should be correct . I have used both of the sign conventions and according to me

real = +ve

virtual = -ve

for convex surface r = +ve

for concave surface r = -ve

and make sure you stick to a single sign convention as it create lot of trouble

and learn the formulae according to sign  convention you follow

eg in this convention

m = v/u

in other is is

m = -v/u

Re: Ray Optics : Sign Convention

The cartesian sign convention is the best and the standard one.

The advantage in this method is it allows one to treat the problem in a coordinate system, and the various values(such as object distance, object height etc) as coordinates of the images/objects.