In series lenses Helios 81 there is a failure connected to pollution of a crown of a lens oils and metal dust. Visually this failure looks as slow closing of a diaphragm at the time of working off of an exposure — “the diaphragm floats”. In this case it is enough to clear a crown of a diaphragm and a seat of a crown of pollution.

helios 81h

21. To unscrew a front limb of a lens.

32. To unscrew the ring fixing optical system of a lens.

43. To unscrew the ring fixing a front optical component.

54. To derive a front optical component.

65. For extraction of a crown of a diaphragm to weaken three stop screws.

86. To derive a diaphragm crown.

97. To clean all lames of a diaphragm, a crown and a seat of a lens where the crown settles down.