7. The Rule Of Five Hundred Today

For cameras with APS-C sensors (like most entry-level DSLRs), you must first multiply the lens focal length by the camera's "crop factor" (usually 1.5x or 1.6x) before dividing.

Example: For a 24mm lens on a Nikon crop sensor (1.5x), the effective focal length is 36mm ( ). The rule would be 7. The Rule of Five Hundred

While the basic rule applies to , modern digital sensors often require adjustments based on their specific hardware: For cameras with APS-C sensors (like most entry-level

It identifies the threshold where the movement of stars across the sky begins to blur into streaks rather than appearing as distinct dots in a long-exposure image. 2. Application and Adjustments 7. The Rule of Five Hundred