Square & Rectangular Filter Systems

Square & Rectangular Filter Systems

For square filters, 2" x 2", 3" x 3" and 4" x 4" were historically very common and are still made by some manufacturers. 100 mm x 100 mm is very close to 4"x4", allowing use of many of the same holders, and is one of the more popular sizes currently (2006) in use; it is virtually a standard in the motion picture industry. 75 mm x 75 mm is very close to 3" x 3" and while less common today, was much in vogue in the 1990s.

This system also consists of various types and sizes of filters. The most popular sizes are 3x3, 4x4 or 4x6 inch models. These square filters generally weigh less than round glass versions and can also give your photos different types of effects. The system consists of three parts: an adaptor ring for your lenses, a filter holder that fits in to the adaptor and the filters. These filters are generally made of glass or plastic, but some are made of a high quality resin or polyester. One square or rectangular filter can usually fit onto various sized lenses. They often fit onto them with adapter rings. Some of these filters are available with soft or hard transitions from dark to clear. A soft edge is good for wide angle lenses and a hard edge is good for normal and longer sized lenses. The filters range anywhere from about $10 to about $100.

The French manufacturer Cokin makes a wide range of filters and holders in three sizes which is collectively known as the Cokin System. "A" (amateur) size is 67 mm wide, "P" (professional) size is 84 mm wide, and "X Pro" is 130 mm wide. Many other manufacturers make filters to fit Cokin holders. Cokin also makes a filter holder for 100 mm filters, which they call the "Z" size. Most of Cokin's filters are made of optical resins such as CR-39. A few round filter elements may be attached to the square/rectangular filter holders, usually polarizers and gradient filters which both need to be rotated and are more expensive to manufacture.

Cokin formerly (1980s through mid-1990s) had competition from Hoya's Hoyarex system (75 mm x 75 mm filters mostly made from resin) and also a range made by Ambico, but both have withdrawn from the market. A small "system" range is still made (as of 2005) by Hitech. In general, square (and sometimes rectangular) filters from one system could be used in another system's holders if the size was correct, but each made a different system of filter holder which could not be used together. Lee,

Tiffen and Singh Ray also make square / rectangular filters in the 100 x 100 and Cokin "P" sizes. v Gel filters are very common in square form, rarely being used in circular form. These are thin flexible sheets of plastic which must be held in rigid frames to prevent them from sagging. Gels are made not only for use as photo filters, but also in a wide range of colors for use in lighting applications, particularly for theatrical lighting. Gel holders are available from all of the square "system" makers, but are additionally provided by many camera manufacturers, by manufacturers of gel filters, and by makers of expensive professional camera accessories (particularly those manufacturers which target the movie and television camera markets.

Square filter systems often have lens shades available to attach to the filter holders. 

Square filters are made in 2x2 • 2x3 • 3x3 • 4x4 4x5.65 • 4x6 • 4x6.5 • 5.65x5.65 • 6x6 • 6.6x6.6 • Cokin A • Cokin P Cokin X • Cokin Z

Square & Rectangular Filters
Cokin Filters
Formatt Filters
Hitech Filters - Hitech filters are made from an optical resin, like the Singh-Ray filters, and are about $35-40 each. A great price for a quality filter. The also come in soft and hard edges though their hard edge is equivalent to the Tiffen or Singh-Ray soft edge.
Lee Filters
Singh-Ray Filters - Singh-Ray filters are $100 each for the standard split ND’s and are made of an optical resin. Available in hard and soft edged. Used by many professionals.  Singh Ray also makes square / rectangular filters in the 100 x 100 and Cokin "P" sizes
Tiffen Filters; -  Tiffen’s filters are made of glass and are a bit shorter than the Singh-Ray filters. They are approximately $95. Tiffen also make square / rectangular filters in the 100 x 100 and Cokin "P" sizes
Shop for Square & Rectangular Filters at these stores
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