NEUTRAL-DENSITY graduated filters, or ND grads, are available in different strengths, as well as graduations, so you can select the filter that best balances the exposure of the sky with the foreground. They’re typically available in one-, two-, three- and four-stop strengths where they graduate from the full strength at the top, to no effect roughly in the centre of the filter.
THE FILTER HOLDER
The most effective ND grads are the drop-in type, rather than screw-in, and for these you’ll need a filter holder. This attaches to the filter thread via an adaptor ring. Most 100mm filters and holders from different brands are compatible, so you can mix and match them if you wish. Manufacturers to consider include LEE Filters, Formatt-Hitech, Cokin, NiSi and Kase.
REVERSE ND GRADS
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