Which is better, the built-in lens or the external lens of a digital camera?

The external lens is the one with several telescopic sections. Up to now, only a few brands, such as Canon, have been insisting on this type of lens. It is not difficult to see that these are all very professional old-fashioned photographic equipment, aiming to insist on the beautiful imaging level. The optical level of this kind of lens is indeed better than that of the built-in lens you mentioned. The only drawback is that it obviously wastes external space, which affects the portability of the camera, and it is easy to get dust in the telescopic part.

and the external lens you mentioned is called periscope lens in the industry, which is very vivid. This kind of lens is a little small, secret, sealed, and can also be optically zoomed, but the lens moves horizontally or vertically inside the fuselage, and the process is more precise. The camera with this periscope can finally be square and square, which can be called a real "card machine". The disadvantage is that the limitation of aperture and lens aperture makes the imaging effect slightly weaker, but it is also within the range that non-professional users can completely ignore.

do you understand?