Iris Type Fader
Bolex Product Code :- IRIPA
Before the introduction of the variable shutter on the H16 the only way a fade in or fade out could be accomplished in camera was with the use of this accessory.
Paillard Bolex sold it as the totally closing iris assembly (also known as the Iris Vignette). This device screwed into the front thread of the early versions of the following Kern lenses.
25mm f1.4 Switar
25mm f1.5 Switar
26mm f1.9 Pizar
25mm Genevar
It cannot be fitted into the normal front filter mount (32mm) found on the later Kern lenses. More a curiosity than something that useful today
The unit gives the effect of defocused brackets coming in from the left and right side of the picture.
It does not do a circular iris fade and certainly not the fade to black of the later variable shutter.