70-200mm lens

f4.0 at 200mm

A few years ago a purchased 3 lenses for $45 and a Cold Stone ice cream. These were a 50mm f.18 that was manual focus, a 24mm fa2.8, and a manual focus 70-200mm f4.0.

I never bothered trying the longer lens until now. While it doesn't work well inside because the room isn't really bright enough for it, it does provide excellent bokeh for macro photos despite the f4.0 aperture at longer lengths.

This is demonstrated here, where the longer focal lengths lead to more bokeh.

The narrower field of view can also be useful for taking portraits without including a wide angle background. I haven't been out to try a portrait yet, but it does show less clutter behind the subject for photos taken indoors. Also, the longer focal lengths will tend to compress a person's features rather than enlarge them, and this is generally considered flattering.

Conversely, (not necessarily conversely really) the depth of field is much narrower using greater zooms. While at 50mm at f4.0, a subject 4 feet away would have a depth of field in focus of .3 feet. With the 200mm lens at 4 feet and f4.0, the in focus depth of field is only .2 feet.

f4.0 at 70mm