The 37mm Heliopan Close-up lenses are the simplest and least expensive method of close-up/macro photography. These convex lenses (plus) shorten the focal length at the same focus setting. They are supplied in the most popular screw-in, push-on, drop-in and bayonet sizes. Close-up lenses can be used in combination. To avoid edge unsharpness, one should stop down to at least F 5.6 or F 8. No exposure correction is necessary. This will allow you to shoot your stamps, flowers in your garden, your jewelry collection and many other small items.