both of them are good.

1, 16-35mm lenses are small and wide-angle, which is suitable for shooting tourist scenery, people, food and children. The lens has relatively low preservation rate, high price, heavy weight and average performance.

2 and 51mm lenses are suitable for portraits, weddings, street shooting and children. The lens is relatively easy to control, relatively low in price and light in weight.

if users like to shoot humanities and sketches, they can choose a 35mm fixed-focus lens. If users like to shoot portraits and children, they can choose a 51mm fixed-focus lens.