>>3431074Optical engineering is a game of trade-offs. Center sharpness, edge sharpness, zoom capability and if so zoom range, maximum aperture, size and weight, cost, ease of manufacturing, bokeh, other aberrations like CA and coma, distortion, vignetting, autofocus speed, each one of these things is in direct conflict with several of the others. Basically in order to get zoom at all you have to trade something away, and the larger you want the zoom range to be, the more compromises you have to make elsewhere.
This is the reason why consumer superzooms have a big zoom range but tend to be slow and not optically great, they optimized for zoom range and low cost. Pro zooms are much better optically and have a larger aperture, but they're bigger, much more expensive, and have a limited zoom range. They both made compromises, just different ones.
You can, by the way, make a large-aperture superzoom of superb optical quality, they're made for the cinema market. They cost as much as a new car.
