TRICK WORK 239At first we used a reflex attachment, but this involved the use
of long focus lenses, which was not advisable. More recently we
have been using the 35mm Alpa Reflex and have found it highly
satisfactory for this as well as other types of successive exposure,
35mm stereo. The extra width of the frame permits gauge crop-
ping, and still leaves sufficient film for mounting to correspond
to any of the three accepted widths now in common use.