Originally Posted by Ed Sukach
That is interesting. I had always heard that the so called normal lenses (related to equivalent human vision) were those that were near the diagonal of the format. That would be near 50 mm for 35, 75 or 80 for 6X4.5, 150 for 4X5 and 300 for 8X10. I don't know where this "normal' designation came from. However, I don't know that I personally see the world at the 150 focal length in 6X 4.5, 300 mm length in 4X5, or 600 mm in 8X10 which is what your comment would indicate. That seems to be a fairly strong telephoto view. (It could be that maybe I am just not focused enough in my perceptions)...
At any rate, explain further...I have a feeling that I am about to learn something here.