Normal,Standard Lens 50mm/Focus,Focal Length.(Post.no.90).

I have let u know about the wide angle and telephoto lenses. However these lenses came later in 35mm SLRs. The first interchangeable lens which was originally introduced with these cameras was a 50mm Lens i.e. Prime ,Normal or Standard lens, as it was called.....LET US SEE the 'focus' and 'focal length'.

ALL PARALLEL RAYS COMING THROUGH THE LENS MEET AT A POINT THAT IS CALLED 'FOCUS' AND THE DISTANCE FROM THE CENTRE OF THE LENS TO THE FOCUS IS CALLED 'FOCAL LENGTH'

Why 50mm lens is called a normal, prime or standard lens? Because the way it produces the perspective, which closely matches that of the human eye. Therefore, the images made with a 50mm lens have a natural and uncontrived look, that is better for available light photography with wide apertures, such as f1.4, f1.8. These lenses are useful because of:

Greater speed;

More Pro results;

Superior optical performance;

Greater compactness and light weight; &

Lower cost..

This lens is in contrast to wide angle lens which has shorter focal length and telephoto lens which has a longer focal length than 50mm, as mentioned in previous posts.....In all these three types lenses, you have to move back and forward to adjust the distance you would like to shoot by covering desired areas.

This picture was shot by a 50mm lens..

........................................................................to continue on next post.