Mirror failure is common in older film SLR cameras.
In single lens reflex (SLR) cameras, a retractable mirror reflects the subject off of the surface of a small stationary mirror and into the viewfinder. When the shutter fires the mirror flips up quickly, allowing light to pass through the shutter and meet the film. The mirror then retracts again once the shutter has closed.
Sticky Light Seals
When the retractable mirror flips up, it is cushioned by foam seals that are glued to the inside of the camera to prevent light leakage. Over time the glue and foam can erode, leaving a sticky residue in place of the seals. The mirror can easily stick to this residue when it retracts upward.
Stuck Shutter or Advance Lever
Mirror camera failure is more common in older SLRs equipped with a manual film advance lever, the mechanism that moves the film and cocks the shutter simultaneously. As a result of rapid shooting or forceful winding, the shutter may become stuck in its open position. As the mirror flips up to accommodate the open shutter, it will remain this way as long as the shutter or advance lever is stuck.
Solutions
Installing fresh light seals is the best way to prevent mirror failure as a result of sticky, eroded seals. Do-it-yourself sealing kits are available at camera stores and online camera retailers. Mirror failure as a result of a stuck shutter or advance lever may be symptomatic of a more serious mechanical issue. Consultation with a camera repair professional generally is recommended in this case.
Tags: mirror flips, advance lever, common older, failure result, Mirror failure, retractable mirror
