Part of an
ERS containing
lens(es) and incorporating a
colorframe holder. Hard or soft focus is achieved by moving the lens tube forward or back within the
barrel. On many modern
instruments, the lens tubes are interchangeable and available in 5°, 10°, 14°, 19°, 26°, 36°, 50°, 70°, and 90° sizes.
m_790lens_tube_blck_lrg.jpg
A 19° lens tube.