SUMMARY
David Bergman explains that camera shutter actuations, the physical movement of the mechanical shutter, are often misunderstood when buying used cameras. Shutter life ratings vary significantly by camera model, from 100,000 for entry-level to 500,000 for professional bodies. Bergman suggests a shutter count under half the rated spec is generally a safe purchase. He also notes that electronic shutter use and cameras without mechanical shutters can affect wear, and provides methods for checking shutter counts on Nikon, Sony, and Canon bodies.
TAKEAWAYS
Shutter actuations measure mechanical shutter wear, a key factor in used camera value.
Rated shutter life varies by camera tier: entry-level (100k), mid-range (200-300k), pro (up to 500k).
A shutter count below half the rated spec is considered a low-risk purchase.
Electronic shutter use and physical condition can be more important than shutter count alone.