Join Brent Winebrenner for an in-depth discussion in this video Reviewing aperture, ISO, and shutter speed, part of Lighting for Photographers: Flash Exposure Fundamentals.
In this movie we'll review in more detail how the exposure variables, ISO, shutter speed,…and aperture work when using flash.…Then in the next movie we'll introduce two new variables, the power of the flash, and…the flash to subject distance, which when considered in combination with one another determine brightness or luminance.…To review, let's start with the variables you should already be familiar with. First off, ISO.…Let's see the visual effect of changing your ISO by looking at a series of images that…I have shot in a controlled environment.…
I began at ISO 100, and I bracketed the ISO in third stop increments all the way to 1600…without adjusting any other exposure setting.…As expected, the mannequin in front is properly exposed in the first frame, while the mannequin in back is underexposed.…As I increase the ISO the exposure got brighter until at ISO 400, the mannequin in front is…two stops overexposed and the dummy in back is properly exposed.…As the ISO continue to increase both manikins became increasingly overexposed.…
Even with today's automatic flash systems, there are good reasons to understand how flash exposure really works. Brent details these concepts in this course. The course describes how to calculate the true power of your flash and how to modify its output to match your needs, a technique that can extend battery life, reduce recycle time, and provide exposure control that is more predictable than fully automatic modes. The course concludes with several shooting scenarios during which Brent explores the creative use of gels, reflectors, and other light modifiers.
- Understanding exposure basics
- Reviewing aperture, ISO, and shutter speed
- Adjusting strobe power and flash to subject distance
- Finding the guide number of a strobe
- Making calculations based on ISO
- Understanding power ratios