Multigrade Kit of 12 Filters
Photographic Darkroom Filter Kit
There are 12 filters in the Ilford Multigrade darkroom filter set, covering the equivalent of paper grades 00 to 5, including half grades. The filters are available in squares for use above the lens, and mounted in holders for use below the lens. Filter 00 (yellow) gives the lowest contrast, while filter 5 (magenta) gives the highest contrast. If your enlarger has a filter drawer, you can simply drop filter squares into the drawer to change the contrast of Ilford Multigrade paper. If your enlarger lacks a filter drawer, you will need to use mounted filters, by sliding them into an adaptor under the lens. If you plan to make prints with divided filtration, using a below-lens kit reduces the risk of moving the enlarger head between exposures.
Multigrade filters are easy to use, because they are density-balanced. No complicated calculations are needed when changing from one filter to another. Filters 00-3 1/2 require the same exposure; filters 4, 4½ and 5 require twice as much exposure. For example, if a print made with filter 2 requires an overall exposure of 10 seconds at f5.6, a print of similar overall density made from the same negative will need 20 seconds at f5.6 when using filter 4½.