A broad variety of standardized pipe fittings are available; they are generally broken down into either a tee, an elbow, a branch, a reducer/enlarger, or a wye.
When the operator is satisfied with the arrangement, the photographic material is exposed with light, usually by switching on an enlarger or other artificial light source.
When he wanted a print that was larger than the original negative size, he used an enlarger to create a larger inter-positive, then contact printed it to a new negative.
