Abstract: The invention relates to the use of oximesulfonic acid esters of formula I ##STR1## m is 0 or 1 and x is 1 or 2; R.sub.1 is, for example, substituted phenyl, R.sub.2 has, for example, one of the meanings of R.sub.1 or is unsubstituted phenyl, C.sub.1 -C.sub.6 alkanoyl, unsubstituted or substituted benzoyl, C.sub.2 -C.sub.6 alkoxycarbonyl or phenoxycarbonyl; or R.sub.1 and R.sub.2, if necessary together with the CO group, form a ring, R.sub.3, when x is 1, is, for example, C.sub.1 -C.sub.18 alkyl, phenyl or phenanthryl, the radicals phenyl and phenanthryl being unsubstituted or substituted, or R.sub.3, when x is 2, is, for example, C.sub.2 -C.sub.12 alkylene, phenylene or oxydiphenylene, the radicals phenylene and oxydiphenylene being unsubstituted or substituted, as latent acid donors, especially at wavelengths over 390 nm, and to the use of the compounds in the production of photoresists.