Benzophenone derivatives of formula I R.sub.1, R.sub.2 and R.sub.3 are each independently of the others hydrogen or C.sub.1-C.sub.4alkyl, cyclopentyl or cyclohexyl; R.sub.4, R.sub.5 and R.sub.6 are each independently of the others hydrogen, C.sub.1-C.sub.4alkyl, cyclopentyl or cyclohexyl; R.sub.7 and R.sub.8 are each independently of the other hydrogen, C.sub.1-C.sub.4alkyl, cyclopentyl or cyclohexyl; with the provisos that (i) at least one radical R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8 is other than hydrogen; (ii) when all radicals R.sub.4, R.sub.5 , R.sub.6, R.sub.7 and R.sub.8 are hydrogen and only one radical R.sub.1, R.sub.2, R.sub.3 is C.sub.1-C.sub.4alkyl, that radical must be in the meta-position of the phenyl ring; and (iii) when all radicals R.sub.1, R.sub.2, R.sub.3, R.sub.7 and R.sub.8 are hydrogen and two of the radicals R.sub.4, R.sub.5 and R.sub.6 are hydrogen and the remaining radical R.sub.4, R.sub.5 or R.sub.6 is C.sub.1-C.sub.4alkyl, that alkyl radical is not bonded in the para-position on the phenyl ring; are found to be especially suitable in photocurable compositions in respect of solubility, reactivity and a low level of yellowing.