For this exercise we are to use a telephoto lens and position ourselves far back from the action/subject, then note the advantages and disadvantages.
I actually used a telephoto lens for the previous two exercises:
The benefits of using a telephoto lens:
I think the main advantage of using a telephoto lens while photographing people unaware is that it is so much less intrusive. I didn’t feel as uneasy as it can put a comfortable distance between the camera and the subject. So much so, that sometimes they are totally unaware of your presence.
Framing subjects is significantly easier with a telephoto lens, and you can avoid getting other people in the shot at times by using a tight zoom.
Something else I’m fond of is that when you’re significantly zoomed in it creates a shallow depth of field, which creates a blurry background – making the subject stand out more, and creating a pleasing aesthetic element.
People notice a big lens. While its more comfortable to step back from subjects, people are much more aware of cameras with big lenses. This can make them feel uneasy, and it can make the photographer feel as if they’ve been caught out trying to sneakily take peoples pictures.
Telephoto lenses are sometimes bulky and heavy. They require more effort when carrying around for a significant amount of time.
Telephoto lenses are often harder to hold still when zoomed in which can produce blurred shots. A way around this would be to use a tripod, but for street photography this would not seem like a suitable option, unless you were looking for a fixed position at a location. Sports games would be a good example of this.
A side issue with the disadvantage mentioned above is that you need a faster shutter speed to eliminate the possibility of camera shake.
Lastly the photographer can sometimes feel disengaged from the subject. The distance between both parties can often be evident in the image. If I had used a smaller lens it may have captured more of the action/environment/atmosphere making it feel like the viewer was in the action, rather than observing from a distance.