This exercise is an investigation of focal length and technical skills. For the purpose of this exercise my camera was set up on a tripod using the 18-55mm kit lens then I switched to my 55-250mm telephoto lens, I used my garden as the background.
I took several images at different focal lengths. They are not the greatest images but they serve the purpose.
In the images you can see that as the focal length increase the background surrounding the door decreases. The camera is static but the angle of view as decreased without me moving the camera physically. The shot that feels closest to my eye vision is 23mm focal length image.
A camera lens works by refracting the available light from the scene and converging it at a single focal plane on the sensor of the camera. How much of a scene a lens is able to bring into view depends on its focal length which is measured in millimetres( mm) this is the distance between the lens and the sensor. My Canon 600 uses APS-C 1.6 crop factor.
I changed my lens to get more perspective and a clear distinction between 18mm and 100mm focal length . Zooming in from a fixed viewpoint does not change the appearance of things in the image. you can see between the first and last shot that their perspective geometry is exactly the same. To change the way the subject looks, a change in focal length needs to be combined with a change in viewpoint.