Attaching Filters to Your Video Camera Lens
Digital video and film cameras have lenses on the front through which light is twisted and contorted, then read and printed by the motion camera. Often times you are going to want to alter the image that is interpreted by this lens from the outside in. You can usually do this through different types of filters that you can attach to the lens. Many of these filters are going to need a way to attach to the lens in question. This is where an adaptor ring comes in.
An adaptor ring bridges the gap between the lens and the filter. Most lenses will allow you to secure an adaptor ring on the front element or over the barrel. You will then make sure that the filter you are using is fastened there with another adaptor ring, lens shade, or another alternative. The filter than then be secured properly to the lens, which is important for manually applied physical filters and not ones that are built into the camera. This has become even more important for many newer cameras that require physical filters to be applied to the lens, and is not going to be relevant for cameras that have a secured lens and does not allow for the changing of lenses.
Adaptor rings require you to be noticeably sensitive when using them. Be careful when securing the screws with these rings as you have the possibility of damaging the filter, the lens, and the camera. There are a number of different materials and substances that can aid in making this process smoother. The primary thing to remember is that the adaptor ring does not fit into the new paradigm of resilient consumer equipment, and instead needs to have the production care that is normally afforded more traditional professional equipment.
Retainer Ring and Step Up Ring
If you are looking to get two filters on the lens you are working with then you can use what is referred to as a retainer ring. This retainer ring simply allows you to double up on the lens. If you are working disproportionately with a very large filter and a very small lens then you are going to have to use a specific type of ring. This type of ring is called a step up ring, mainly because you are matching items of two different sizes.
Make sure that if you are planning to use a number of filters you find a camera that can handle them. To do this you have to make sure that your lenses actually are able to take an adaptor ring or retainer ring, otherwise you may have a problem and will be limited to what type of filters you can use. Also note that many filters go behind the lens and may even be built in the camera, such as neutral density filters. If these behind the lens filters are all you are going to need then you may not actually have to concern yourself this when you are shopping.