Terry, I hope the above comments aren't confusing you.
A 35mm from a C645 is still a 35mm when put onto a 35mm camera. Just as a 210mm on an 8X10 camera is still a 210mm when put onto a 35mm camera. The lens(es)description (35/210/etc.,is of focal length that don't change based on what body it may be connected to.
What does change, however, is the angle of view based on the camera's film format.So, a 35mm from any system(or a 350mm for that matter) when coupled to a 35mm body will give you angles of view that as a 35mm user, you can relate to.
When one couples a 35mm lens to a C645 you get an angle of view approximately the same as a 21mm lens on a 35mm. Just as it is when you use an 80mm on the C645, being similar to a 50mm on a 35mm body.
now your comments are confusing Me [i'm dumb]. I'm now considering an adapter to use a Hassy 110FE lens on my Contax SLR. I was expecting it to behave exactly as a 35mm format 110mm lens would - a medium 'portrait' telephoto. But, what you seem to be saying is that it will have the properties of a 55mm lens on my 35mm SLR.... Er, isn't that what you're saying? Wait-
These two sites seem to suggest that what i was thinking is correct, right? The 110mm Hassy lens for the 6x6 format will be a 110mm lens on a 35mm SLR. On the Hassy, it's roughly equivalent to a slightly longer than 'normal' lens (55mm?), but on the 35mm camera it'll be a 110mm tele lens, right?
That's prolly what you're saying, too, but, as i said earlier.... duh.
So, to capsulize: the focal length, as measured/specified in millimeters, always stays the same. But, its field of view, or how it works relative to the film format does change.
Did i just make this worse?
And, back to the original question/comment - Yah, it's almost imperitive that Contax come out with some reasonably fast wide angle primes. My first choice would be a 35mm f1.4 or f2. This will be all the more important if they come out with a digital without a fullframe sensor. It would be inexcusable not to have a fast prime that will equate to a 'normal' (50mm) focal length. And, wider still lenses would be required to equate to 'wide-angle' primes. I can't see pros buying into a system that doesn't have these 'basic' components.
Derek. Sorry for the confusion. You are correct in stating that if you put a 110mm from a Hasselblad system onto your Contax 35mm you will get a 110mm short telephoto.(35mm camera reference point) What I was trying to say was that this same lens on the 6x6 Hasselblad format is a "normal"(around 60mm on 35 cameras)lens.It would also be an extreme wide angle on a 8x10 camera
Hope this helps.
Many people use the 35mm camera format as a default position.(reference point) Having cut my photographic teeth at aged 10yrs, on 6x9, that is my reference point! I was also trying to say that irrespective of the camera format the lens is used on, the focal length remains the same. Only the angle of view changes as a result of the camera format.
Javier, a 28 in N mount will never happen. If you can accept manual focus Contax, strongly consider the Aria + 50/1.4 + 28/2.8 - my favorite kit. For Contax AF, there is the RF G1/G2 + 45/2 + 28/2.8 option.