From: "David Dyer-Bennet" < : I don't believe (it predates me a bit) that people were routinely : mounting their old familiar 4x5 lenses on their new 35mm bodies. : Whereas in the DSLR world, we *are*, and in fact the new bodies look : very much like the old bodies. Many of us used them side-by-side for a : while, moving lenses from one to the other in the middle of a shoot. : : So the relationship is more relevant now. I started on 35mm but when I learned about and started using 66, I familiarised myself with the lenses and their associated relevance to 35mm - that is to say I learned that an 80 was considered normal for that format. I went through the same process with 4x5, 8x10, 16mm, half frame, 6x9 and 6x17 - in the end I had no issues and if I wanted say something that behaved like a 100mm did on a 35mm camera it was nothing for me to think 'grab the 150mm (or 270mm or 450mm or whatever) : Yeah, as I said in my physics rant, the physics always wins. And : certainly relating to 35mm film equivalent focal lengths is a silly way : to do things -- *except* for people with a deeply trained-in knowledge : of what 35mm focal lengths mean. Which turns out to be...practically : all the photographers on the planet. I guess you relate to whatever is familiar - and equivalents aren't that silly when you consider the way its done currently, which is to ignore the relevance and just multiply the focal length by 1.4 for camera A or 1.6 for camera B or 1.8 for camera C - or worse, mark the lens as a 35-70 when it is actually a 19-39 k
