well honestly i was unsecured of my concept but some net info:
The importance of focal length
The choice of a lens’s focal length can be an important criterion when composing an image. But what exactly is the focal length of a lens?
In technical terms, this refers to the distance between the rear nodal point of the lens and the focal plane, meaning the plane where subjects at infinity come into focus. In practical terms, and using the example with the magnifying glass mentioned above, the focal length of the magnifying glass would be the distance between the magnifying glass itself and the piece of paper when the image of the sun (the little patch of light) is smallest.
and yes you can take a picture of the sun with the right settings:
here the concept of focal lenght:
so well its a fact lights waves when you dont look and particles when you look
and i found a way to prove it
burning a paper with a lens, lights a particle and lens make all light from the sun in a single spot
lens with a box so the observer cant see, lights a wave and the same lens now makes the sun from the sun spread