This slide/negative copier uses a Canon 5D camera and Canon 100mm macro lens. The slide is held in place with a slide holder that I borrowed from my slide projector. There is a diffuser glass between the slide or negative and the light. I use it in a dark location to minimize the chance of getting a reflection off of the slide or negative.
I modified this slide copier so that I could hold a negative rather then a slide as pictured. I used a scrap of matting board with a hole cut to sandwich the negative and held it together with clothes pins.