Filter systems explained
ND filters are available in either round or square designs. The round filters simply screw onto the front of your lens, while the square type need a holder and an adapter ring to attach them.
Choosing between the two systems depends on the type and number of filters you’re likely to use, and also the lenses you’ll want to use them with.
Round filters are ideal for using individually, and if all your lenses have the same filter thread size.
Square filters are better suited for using more than one filter at a time, or if you own a range of lenses with different thread sizes.
Buying the whole system for square filters can be very expensive, but as a stopgap you could consider simply holding the filters in front of the lens.
You need steady hands and the camera on a tripod for this to work, and it won’t be easy to hold the filter still for exposures of a second or more.
Another solution is to use a tiny amount of Blu-Tac to help keep the filter in position while you hold it.
Square filter systems
There are three main systems, and they all comprise three main components: the filter, a filter-holder, and screw-in adapters of different sizes to fit different-sized lens threads. Some are interchangeable, so a Cokin Z-Pro filter will slot into a Lee holder, but the adapters are specific to each holder.
These 85mm filters offer a good value route into square filter systems, but the size limits their use. The filters are too small to use successfully on many wide-angle lenses, or even large-diameter lenses, without causing vignetting in the corners of the frame.
The 100mm filters of the Cokin Z-Pro system make them a much better option than the P-series if you use (or are thinking of buying) a wide-angle lens. The filter holder is modular to vary the number of filter slots, which is particularly useful for avoiding vignetting on wide-angle lenses.
These are a popular option among pros due to their quality and consistency. Like the Z-Pro system, the filters are 100mm wide, and the holder is modular, allowing you to vary the number of filter slots, but the range of accessories you can attach to the Lee holder is greater.
PAGE 1: Best photography accessories: Tripods
PAGE 2: Setting up your tripod & features to look for
PAGE 3: Getting the most from budget flashguns
PAGE 4: Tips for using manual flash
PAGE 5: Using neutral density filters
PAGE 6 – Filter systems explained
PAGE 7 – Using ND grad filters
PAGE 8 – Using polarisers
PAGE 9 – Common problems caused by filters
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