Ilford Below Lens Filter Set 8.9cmIlford Below Lens Filter Set 8. 9cm This set from Ilford includes twelve filters which are numbered 00 5 in 1 2 steps, with the lowest filter number corresponding to the softest contrast. They can be used above or below the lens and can be cut to fit the enlarger filter drawer. It comprises 12 mounted contrast filters, a mounted safelight filter and a filter holder. Multigrade filters are very easy to use: no complicated calculations are needed when