Not a flame war. A legitimate lens comparison

TheManWhoWas wrote:

Basically, if your criteria for choosing a camera is whether it takes exactly equivalent pictures to a FF camera, then buy a FF camera. "Equivalence" has shown that the same "light gathering" lenses are much the same size on every system because they are, um, equivalent.

But anyone buying a smaller sensor camera knows they are trading off some IQ in exchange for a smaller overall package. So we can use our tiny 1.8 primes that don't have equivalents on larger systems. And no they don't give the same DOF as a 1.8 of an "equivalent" focal length on a larger system, but so what?

Trying to build an MFT system that exactly matches a FF system in every respect is just silly.

Oh, and people need to stop using "fast" when talking about DOF equivalence. A 1.8 is a 1.8 when it comes to "speed" (like looking through a viewfinder on a DSLR) but obviously they all vary with focal length when it comes to DOF, and smaller focal lengths give more DOF, and smaller sensor systems tend to involve using smaller focal lengths. That's all the difference is.

Not my criteria. Just trying to make sure that I 100% understand things. I do not know a lot about M4/3. I had one camera with two lenses 8 think three years ago.

Yes equivelancy and fast are some terms that 8 should be careful with. 1.8 is 1.8. Regardless of size. I think where new people to this conversation get confused is that depth of feild is completely different. Focal length is focal length. A 20mm lens on m4/3 is not a 40mm. It looks like a 40mm because of the format change. Most people do not make the same change when regards aperture. New people that get into this conversation get confused. They think that 1.8 is 1.8. Well of course I am going to get the less expensive system it is the same thing. That is where I am going with this conversation. Not that one is "better" than the other. There are strenths and weaknesses when you compare cameras and le ses that go way beyond this part of the conversation.fast is a lot easier to type than shallow depth of feild. You say everyone looking to buy a camera knows this. They obviously do not if you look through the forums