Selenium toning won`t work well on underexposed negs and will give you plus one result. If you need more than selenium does, there are other ways.(posted 9258 days ago)Sepia Toning. You should see the dnesity in the highlights increase by one or more stops and this will work with underexposed and under underdeveloped negs. First soak your negs Then bleach out your negs in solution A and wash. After washing and clearing all bleach out of negs, put the negs into solution B until desired intensification has accrued. Solution A Water 500 ml Potassium Ferricynide 35 grams Sodium Carbonate monohydrated 15 grams Potassium Bromide 15 grams Water to make 1 ltr
Solution B Packet B from Kodak Sepia Toner Package add packet to 1 ltr. of water (don`t use the Bleach in this packet.)