Allows you to use smaller size filters on lenses with a larger diameter thread. The first number is the size that screws into the lens, the second number is the filter size. Step " Down" Rings May Cause Vignetting.
Reviewed by 3 customers
This allows me to share filters between cameras and eliminates the need for duplicate filters.
This was a very inexpesive way to use all my current filters with a new camera. The price was half that every else was charging.
Switching to digital from TLR film cameras I can use all my efects filters I have built up or made in the many years I have had the film cameras.Pentax lenses have a wide flange in lens front that does not vignette when using the adapter