I photographed 13,000 slides at 100 slides/ hour including transfer to an iMac & editing. I used a Nikon D5500, 40mm f2.8 Dx macro lens, Nikon ES-1 slide holder and SB-800 flash set to TTL. Aperature priority at f11. File size about 7 mb. TFraker

The Nikon 40 mmDx Macro is perfect for copying slides with the Nikon ES-1 slide holder.

The ES-1 slide holder works perfectly with the micro-nikkor 40mm f2.8G DX lens on my Nikon D5500 and on the D750. No extension tubes or step up ring needed. Much cheaper than the 55mm or 60mm macro lenses.