- #1
PrakashPhy
- 35
- 0
Until today I learned in geometric optics that
On the basis of this the lens formula would be
1/u + 1/v = 1/f [u=obj distance v= image distance f= focal length]
But recently, the new textbook i follow writes that. "All distances towards the left of the lens are taken -ve and all other to the right are positive"
For a convex lens if the object is beyond 2f at a finite distance the new sign convention would give 1/v - 1/u = 1/f ;
I know it will not cause problem if i stick to one convention only but i wish to follow universal convention. So i would like to know if there is anything like "Universal sign convention" for geometric optics
- Object distance +ve for real object else -ve
- Image distance +ve for real image else -ve
- Radius of curvature +ve for if light comes to the surcace from the side lying center of curvature else -ve
On the basis of this the lens formula would be
1/u + 1/v = 1/f [u=obj distance v= image distance f= focal length]
But recently, the new textbook i follow writes that. "All distances towards the left of the lens are taken -ve and all other to the right are positive"
For a convex lens if the object is beyond 2f at a finite distance the new sign convention would give 1/v - 1/u = 1/f ;
I know it will not cause problem if i stick to one convention only but i wish to follow universal convention. So i would like to know if there is anything like "Universal sign convention" for geometric optics