Filter Basics: The Case for Modular Filters

by | May 5, 2021

Today’s Post by Joe Farace

Back in the film days, camera manufacturers tried to standardize on a single filter size for most of their lenses but that seems to be no longer the case. These days it seems to be more of a filter smorgasbord. And when you decide to add lenses to your system from either camera or third-party lens manufacturers, you can easily find yourself owning lenses that have many different filter sizes.

Before.filterUsing modular filters overcomes this obstacle by letting you to purchase one filter that fits all of your different lenses. That means you only need to own one ND, gradient, or polarizer filter and it will fit all your lenses. These filters typically slip into a holder that uses adapter rings that will fit different lenses and even different format cameras. All you need is a single, inexpensive adapter ring for each of your different lenses thread sizes. The sizes of filters and the type of adapters used may vary by modular filter manufacturer but some company’s filters are compatible with other company’s modular systems.

Tobacco2sunsetModular filters can be square or rectangular, although companies, such as Cokin, Hi-Tech and others offer round filters as well. These filters are also more than likely to be made out of plastic. These plastic filters are typically formulated using the same kind of optical resin material that’s used in eyeglasses so optically you should have no concerns.

Tips: Cokin’s original A filter system uses 75mm x 75mm filters. The larger P (84 x 84mm) filter system was designed for medium format cameras but the not-so-available-anymore A/P adapter lets you use the A filters in a P filter holder so (if you can find one on eBay) it’s not necessary to buy P filters if you already own equivalent A versions. Another Tip: When using A-sized filters on shorter focal length lenses some vignetting can occur so watch out for this problem on your camera’s LCD preview screen.

Cokin offers the large (6.7 x 5.1) inches X-Pro size that uses a holder that’s similar to the A and P series but with more rugged construction. Cokin launched a 130mm wide Z-Pro series. A (may be hard to find) Z/P adapter lets you use Z filters on a P Holder and the Z/P Wide Angle Adapter lets you use Z filters on a P Wide-Angle Holder.

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