The present invention is directed to an epoxy film composition, comprising: novolac resin; solvent; a photoacid generator having the structure A+B− and having a pKa of −5 or less; and a photolabile quencher generator having the structure C+D− and having a pKa greater than −10; wherein B− and D− are different; wherein the amount of the photoacid generator ranges from 0.1 to 7 wt %, based on the total weight of the composition; and wherein the amount of the photolabile quencher generator ranges from 0.1 to 20 wt %, based on the total weight of the photoacid generator. The present invention is also directed to a method of controlling photospeed in a negative photoresist.