Greg writes: "Pardon my interruption but I think what Dave is talking about is compression as opposed to perspective. The vertical and horizontal placement of objects does not change from one focal length to another however the relative size of objects does change with focal length as does the apparent depth of the image. Doesn't it to you?" there really is no 'wide angle' or 'tele' effect with lenses when it comes down to it - they all just have an image circle size and they all just show what's in front of them (distortion aside) - the wide angle or tele effect comes into play when you take into account the format. pick lens 'A' , lets say it's a 80mm and has a really big image circle. If you put it on a 16mm camera the tiny 16mm slice of film only sees the center of the image circle - the effect is that it captures only a narrow slice of the image and the effect is that it is a long lens *for that format*. pop it on a 6x6 camera and the film sees a wider slice of the scene, conveniently it is the 'normal' focal length for that format. Fit it to a 5x4 camera and the film will see even more of the scene - it is a wide angle *for that format* If I were to crop the middle out of that 4x5 neg say to 6x6 and then down to 16mm, the images would look *identical* to the ones taken with that respective format. no change in spatial relationship, no compression, no expansion has occured. isn't optics fun? :-) karl
