Exposure may only be controlled by shutter speed, film or sensor sensitivity, or a slot-in neutral density filter.

It does not work well at close focus (closer than 6 m) and the fixed slow aperture f/8 means it can be used handheld mostly on sunny days.

The small size (14cm long) and low weight (700g) makes it a 500mm lens that can easily be carried around.

The latter proves a very viable solution, even despite the shallow depth of field of the long focal length.

Still, it can of course be used (fully manually) on modern cameras such as Sony E-mount, but requires a different adapter type.