13. Shutter speed control.

The shutter speed is determined by air escaping from a cylinder in which a piston slides as the air escapes, a mechanical linkage releases the second blind to close the shutter after the action of pressing the release has opened the first. The mechanism is fairly robust and reasonably simple in construction. It does, however, suffer a few inherent design problems. The shutter speed will vary day to day, as the air pressure changes - if you take it to high altitudes it will fire quicker for any given setting. Mechanical and wear inconsistencies mean that every camera, particularly today, will behave differently. For this reason, you will see that no speeds are marked on the control. Simply "S" which we shall say = Slower and "F" which conversely is Faster. The best bet is trial and error. I use the shutter at its fastest setting and f/8 with Jessops R200 film when the weather is bright. Dirt and oxidation will slow the shutter dramatically or seize it totally. If sat unused for years the shutter cylinder may have a light coat of oxidation on it (brass again) and it may refuse to release. The only option is to strip and clean the shutter mechanism. This is not a difficult job, and a competent vintage camera repair shop ought to be able to tackle the job without the benefit of a manual. The cylinder will not take kindly to being lubricated, it works best dry - but will oxidize in time as a result. The control knob itself works by progressively uncovering an air escape channel, and this also needs to be kept clean. Large changes of temperature will also affect it owing to expansion or contraction, but under normal circumstances this can be ignored.

It is worth noting that the shutter speeds are slow by modern standards and that appropriate measures be taken when taking a picture. Stand firmly and hold your breath just before pressing the release. Be sure not to jerk the shutter release, the action is quite light and little force should be required to release it.

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