I am going to Tibet soon. I am joining a photography group. The leader of the group said that beginners can use only one camera, which is both wide-angle and telephoto.

Your question is really confusing. For beginners, what the leader said is correct. It is most convenient to use one lens to cover the world. When shooting in Tibet, it can be said to be wide-angle and medium focus. All telephoto focal lengths can be used. But if you already have an 18-105, buying an 18-200 is a bit wasteful. Let me share my thoughts below for your reference.

1. If you just want to be an amateur and don’t plan to invest more in the future, you can sell the 18-105 and buy an 18-200. It’s convenient.

2. If you want to change the camera body in the future and want to further develop in photography, buy the 70-200. This time, I will bring both the 18-105 and the 70-200. I can use them interchangeably, maybe when traveling. It's a bit inconvenient, but fortunately it's a photography group, so we should have time to change lenses.

If possible, it is best to bring more than 2 fuselages. One telephoto and one wide-angle, which is more convenient to use.

I would like to remind you that you can also bring the most primitive fully manual film camera, such as FM2. Some digital cameras can cause altitude sickness, and more than one friend has encountered this. It is better to bring a fully manual car to be safe. After all, it is not easy to go to Tibet.