Flash: Guide Number, Power Settings & Inverse-Square Falloff
This lesson is part of the course
In this lesson
You scale a flash guide number for ISO and power, find the maximum flash distance, and see in stops how fast flash light falls off behind the subject.
Buy the course once for $9.99 to unlock every lesson and lab, the final exam and the certificate – lifetime access, no subscription.
Lessons in this course
- Exposure Value: EV = log₂(N²/t) and EV at ISO 100 Locked
- The Stop System: f-Numbers as Powers of √2, Shutter & ISO Stops, Equivalent Exposures Locked
- Sunny 16 & Light-Meter Readings → a Settings Table Locked
- Field of View: Sensor Size, Crop Factor & Equivalent Focal Length Locked
- Depth of Field: Circle of Confusion, Near & Far Limits Locked
- Hyperfocal Distance: a Table for Landscape Shooting Locked
- Flash: Guide Number, Power Settings & Inverse-Square Falloff Locked
- Motion Blur & Maximum Shutter Time: the 500 Rule vs Pixel-Level Blur (with a Chart) Locked