I want to buy a Pentax K5. What kind of lens is used for the main character set, not too expensive?

Let's talk about the focal length of the lens first: Generally speaking, the focal length of the lens is within 18-70, which is suitable for traveling, 30-50 for landscape portraits, 50-85 for general portraits, 85- 135 for busts and headshots, and 35-50 for family portraits if the place is small.

The head of 17-70 contains a good focal length. The scenery and portraits you mentioned are both available, and the imaging is relatively large. The problem is that the price/performance ratio is not high, it is a bit big and heavy, and it is not worth adding some money to 16-50. 18-55 is the cheapest lens, which basically meets the general requirements. 18- 135 is more general than 18-55. It is a mirror with better quality and lighter volume. If there are no other shots, it is recommended to enter this one. I think DA40, DA70, FA50f 1.4 are all very useful, and you can focus on your most commonly used focal lengths.

Deputy factory lenses such as Sigma and Longteng are cheap, but they are easy to get out of focus, so be careful. If you can test yourself and have room for choice or regression, you can consider it.

For example, Longteng's A 16