Why do we want cameras with interchangeable lenses?
The simple answer is, we want to be able to put wide angle lenses on sometimes, and other times we want long focal lengths.
But that leads us to another question….why not just make a zoom lens that covers both wide AND long, and everything in between, then you don’t need to change lenses?
The simple answer is, because physics won’t let us make a lens that is both wide AND long, without sacrificing quality. In other words, we can HAVE both ends of the range, but the lens will be slow and the image quality will be mediocre.
So I guess you could revise above to: “We want interchangeable lenses so that we can have HIGH QUALITY wide angles sometimes, and HIGH QUALITY long focal lengths other times. If we don’t specifically want this, then there is no point to interchangeable lenses.
But a little research brings up another question….why can’t we use a relatively inexpensive point and shoot with a very long, fast zoom? For instance, the Panasonic FZ-200, that seems to have a fast lens throughout the entire range.
The simple answer is, it has a VERY small sensor. That small sensor is what enables the lens to be WIDE and LONG and FAST all at the same time……but a small sensor is a compromise in image quality.
So I guess you could revise above to: We want interchangeable lenses so that we can have HIGH QUALITY wide angles sometimes, and HIGH QUALITY long focal lengths other times, AND we want a camera with a larger sensor. If we don’t specifically want this combination of things, there are NON-interchangeable lens options, but if we DO want this……..SPECIFICALLY……that’s when we want an interchangeable lens camera system.
When we want it all.
So here’s the irony. Most people…..and by most people, I mean far far far more than 50% of everyone who buys an interchangeable lens camera, will never…………EVER….buy high quality lenses of ANY length.
More or less proving that they never wanted an interchangeable lens camera in the first place.