Still trying to get my head around . I know the focal length only refers to the distance between the and sensor so I get that. Also the focal length number refers to weather it is a Wide angle, standard or telephoto and these determine the field of view.
My problem is understanding which focal length to use for certain shots. Wide angle are pretty straight forward and mostly obvious. But when it comes to standard & telephote I cant quite grasp it. I have been reading DSLR Photography for Dummies. The writer says just by looking at a photo you should be able to determine the general focal length used and has a couple of examples of shots taken and asks you to guess and then gives you the answer. Needless to say I was totally off the mark. One of the shots was a close up from the chest up of a boy which I thought was taken at a focal length of around 55mm but was in fact taken at 170mm. So I assume the photographer had to be standing a fare distance away to be able to get that shot but how was I to know this? What I dont understand is how do you choose the correct , especially a standard , when a lot of the time you can change the field of view by physically moving further away or closer. Can someone explain to me in a simple way?
Thank you for you help!!!