If we think about the idea of documenting (and essentially snap shots of travel), we are talking about information. As a photographer in that context you are providing the end viewer with information about the particular location in which you are standing.
Then if information is the purpose, a vast depth of field is what is required. Most things must be in acceptable focus in order to serve the purpose of documenting and in a sense educating the end viewer. “Fast Glass” or a big aperture is not what is required. Furthermore, a low ISO or completely noiseless composition is not required. A certain level of noise is completely acceptable in order to achieve the purpose of documenting.
I mention noise because there may be times when low light shooting may be required. Again certain levels of noise are acceptable. How much noise one may ask, well, just about any sensor made within the last 15 years can handle shooting at dusk and even at night if one cares to carry a tripod.
For the most part, beginning photographers do not need any brand full frame sensor with a lens that opens up to f/1.4
What is important when documenting is composition and light control or adapting to the available light both of which can be done with a smart phone. Once this is mastered, one can start looking into being an artist.
Once you become an artist and start to see photographs in your head before you make them, then you can start asking what kind of equipment you need to make that photograph.
You may surprise yourself and find out that the camera and lens you thought you needed may not have been the correct choice after all. Maybe you needed a large format film camera.
The Common Rule: A Blog by Danny De La Cruz 