Step-up rings

Step-up rings

The spiral conversion rings change the size of the filter to fit the lens. This means you can use a larger or smaller filter on your lens than would actually fit. If you own several lenses with different threads, you don't necessarily need to buy the right size filter for each one. With helical conversion rings, you can use one filter on many lenses.

Most helical rings are step-up rings, which means they allow you to use a larger filter on the lens than the lens can accommodate. There are also step-down rings, which do the opposite. The problem with these is that they are more likely to cause vignetting in the image. So it's better to buy a large filter, because it's easy to increase the twist of the lens, but you can run into problems when you reduce it.

The range includes step-up rings in almost every possible size and a variety of step-downs.