Variable close-up lenses screw into the filter mount on front of a normal lens, in the same way as ordinary close-up lenses. However, by turning a ring the power can be changed, and different magnifications achieved. Definition is not as good as that provided by a macro lens or by simple close-up lenses, but at small apertures the results may be adequate for some purposes. Try one out on your camera before buying. There is a slight light loss, but not enough to need compensation.
|Camera focus||Attachment focus||Working distance||Subject size||Magnification|
|infinity||furthest||490 mm||390 × 260 mm||0.09|
|infinity||closest||95 mm||126 × 84 mm||0.29|
|closest||furthest||160 mm||141 × 94 mm||0.26|
|closest||closest||41 mm||72 × 48 mm||0.5|