Originally posted by BigMackCam Again, being picky, but the image circle from the lens stays exactly the same. What changes, based on the size of the sensor or film media, is the portion of that image circle that is captured...
I’d have to disagree with you here (respectfully of course). Take the DA20-40, yes the image at the wide end is 20mm regardless of the camera it is attached to, yet on the K-1 the image circle isn’t large enough to cover the entire sensor, leaving the corners dark.
I agree, the actual angle in degrees will not change, regardless of format. I think too much thought is put into what one lens does on one camera as compared to another. Since I’ve always shot at least two formats, I stopped worrying about lens conversions long ago.
I try to tell people to get to know the lens you have with the camera you’re using. If you need wider, then buy a wider lens. It actually makes it easier buying lenses because lens manufacturers have always stuck with one format when labeling lenses. Could you imagine what it would be like if aps-c lenses were labeled with the “crop” factor?