lux said:
I can't believe I'm adding to this but I'm asking a question.
Regardless of what it is called. If I use a telephoto background looks closer than it is.
That is, the pictures of my kids with the elk in the background using the telephoto gets me in trouble with my wife while the one with the wide angle is fine.
Is that because my eyes are about 50mm and the elk looks 4x closer using the 200mm zoom?
That is where you are tripping up, that statement is not true, the background
and foreground look closer, as Souless said, they are both magnified, equally, to keep your kids in the fov you have to move back, this keeps their magnification constant but increases the background magnification
in relation to them. This is perspective, not "lens compression".
Look at the three images Jrista posted off Wikipedia, the bottles are the same size, if you stand closer to the pink bottle the blue bottle looks smaller in relation, stand back and zoom in and the blue bottle appears to grow, but obviously it isn't, however to your eye the pink bottle just gets smaller, which is intuitive as you maved away from it and it takes up less of your fov. They appear to change size in relation to each other and they both become more distant to you, as a percentage the pink bottle gets smaller faster. If you stood 30' away they would both look smaller, but the same size as each other, because the distance between them becomes so much smaller than your distance from you to them.
So if your kids are the pink bottle and the elk the blue bottle, stand close and use a wide angle and your kids appear much bigger than the elk, or a building, or if they are on a ski slope bigger than a mountain or village in the valley, this is because you are closer to them than the elk, mountain or village. Now zoom to a longer focal length and what do you have to do? Move back, once you move back you have changed perspective, you have decreased the size of your subject in relation to yourself.
Perspective is about the relationship of space and the distances between the objects in the image in relation to the observer, it doesn't even have anything to do with a camera or lenses.
I posted the 17m and 200mm images earlier, obviously the 17mm image is cropped, when I took the image I had a much wider fov but if I focused my eye on the girl then I saw the same thing as both, her size in relation to the tree etc was the same.
This is a very misunderstood aspect of image making, I watched a video recently of a respected landscape shooter who insisted he got much better "lens compression" by stitching 50mm images than taking one 24mm image for the same framing from the same place. That is complete bullshit, not only did I lose all respect for him but it annoyed me that people will now repeat that, to be sure, i didn't lose respect for him because he taught something wrong, we all do that sometimes, I lost complete respect for him because he has clearly never looked at his comparative images with a detailed and critical eye, if he had he would have observed that what he was saying simply is not true. Look at some of those gigapan images shot with hundreds of images with super tele lenses, they have the same "compression" and perspectve as one shot from the same place, they do have a lot more detail, obviously, but the same "lens compression" and perspective.
