The slit scan photography that I’m now doing requires that I use, at various times, three different filters: infrared pass, infrared block, and polarizing. The lenses I’m using for the series – 65 mm, 75 mm, 90 mm, 135 mm, and 210 mm – all take different filters. Some of the filters that I need are not available in the filter diameter of all the lenses. In addition, in trying to save some money, I wanted to use the same filter on more than one lens. For both those reasons, I purchased a set of filter step up (or step down, depending on your point of view – more on this later) rings. These allowed me to use the same filter on more than one lens.
A confusing factor is terminology. Some manufacturers say that a step up ring allows you to use a filter of larger diameter on a lens meant to accept a filter of a smaller diameter. Other manufacturers say exactly the opposite: a step down ring allows you to use a filter of larger diameter on the lens meant to accept the filter of a smaller diameter. Read the fine print before you buy.
A source of extreme frustration is an inability in some circumstances to remove the filter from the ring. It is maddening to watch the light fade as you try to remove an infrared pass filter so you can put on an infrared blocking filter to get a sunset. I’ve used silicone rubber to get enough gripping surface so that I could remove filters from lenses, but they do not work at all in providing grip on the ring. I have filters that are essentially permanently attached to their step up rings.
I have decided to abandon the idea of reducing my filter count by trying to use one filter on more than one lens. I am now looking for each of the three kinds of filters in the native diameter of all of my lenses. If I can’t find the right filter, I will purchase an adapter ring, and thereafter consider it part of the filter.
There’s got to be in a better way to attach filters to lenses. I have used cameras that use bayonet mount filters, and they seem to work perfectly. However, they’ve been around for years, and haven’t exactly taken over the marketplace; all but a tiny number of lenses use conventional screw in filters. Are therse filters the QWERTY keyboards of photography?