For this exercise we were asked to use a medium-long focal length lens. I used a 70-200mm.
The first difficulty I encountered was the weight and size of camera and lens. It is difficult to have a steady hand and to try and be unobtrusive (the key to great street photography).
My first session was at a busy railway station:
It was difficult to find somewhere to stand back and take pictures. Once I found a spot that had some chance of working then it became difficult to capture situations that would make a good picture with so many people racing by. For convenience I tried automatic focusing. That just didn't work. My lens was too slow in refocusing every time someone walked by. So had to change to manual focus and manual settings. At railway stations most people are walking briskly. With the picture above it took several attempts to capture the man on the seat without people walking in front of him. I also was trying to get more than him to make an interesting picture. The woman behind pointing balances nicely with the gentleman's hand.
I soon gave up and decided to try somewhere else. I figured Southbank might be easier.
You soon get spotted with a great big lens in peoples faces. Being half term break with lots of children around I thought I was likely to get into trouble here. I decided I needed to find a cafe where I could sit outdoors and quietly observe without being so obvious.
This was the most successful way of achieving "the standing back" brief. I still had problems with people walking by who were to close to me. As I was sitting down I'd just get a big blur of the middle of them. I'd chosen a spot with only occasional vehicles going by so as to reduce that problem.
Overall I didn't find this an easy way of doing street photography. Sure you can get people unaware but it is harder to blend in. I would rather work with smaller equipment and be mingling with people. I don't mind if they spot me. Getting close gets better expressions. I felt more voyeuristic and uncomfortable with this lens. I can see that for someone else this might not be the case. I know people who find it really difficult to take pictures of strangers and would feel more comfortable putting the distance between them and the subject. I don't find it difficult. All of the pictures I have taken on this exercise I could equally have taken with a smaller lens and just got closer. If you are quick you can still get a picture without them being aware of you. I think it very unlikely I would use this lens again for street photography.