Why is it difficult for SLR lenses to achieve large zoom?

Because the CCD (imaging element) of SLR is relatively large, generally above11.6, it will be huge and expensive to make a large zoom lens, and the diameter of the lens is directly proportional to the CCD size.

Generally speaking, the ccd size of ordinary consumer-grade DC will not be larger than11.8, so the telephoto lens size will not be very large, and it is easy to manufacture and cheap.

Because the ccd of SLR is large, the imaging effect is completely different from that of consumer-grade DC, which is very clear, but the lens of ordinary DC can't be used on SLR, which is too small.

So we often see that reporters' SLR is a gun barrel.