1. What is dynamic range? 2. If one camera “captures a smaller dynamic range” than another camera, and they both took a picture of the same scene, how would their images differ? 3. A histogram is a graph of all the pixels in the image, based on what? (what’s the x-axis?) 4. If an image has “low contrast”, its histogram would have pixels: a)Bunched up towards the middle b)Bunched up towards the sides c)Distributed evenly 5. For question 4, why? (what does a histogram with pixels in the middle, sides, or distributed evenly tell you?) Week 13 Quiz

? Crushed shadows

? Blown highlights

RedGreenBlue 111 RedGreenBlue 555 Not all “crushed shadows” are actually black

RedGreenBlue 10 RedGreenBlue 50 As long as pixels aren’t clipped to pure black (or white), detail still exists Transformation: Pixel value x 10

Real-world examples Tools Exposure adjustment -Levels -Curves Better Tools Selective shadow/highlight adjustment High Dynamic Range (HDR) blending

Important side effect Raising shadows reveals noise!

RAW Headroom Original JPEG -4EV adjustment in ACR RAW -4EV adjustment in ACR RAW format gives extra dynamic range headroom to restore crushed shadows and blown highlights

Fill FlashOriginal Shadows adjustment Fill flash Low-power flash can “fill in” shadows Better tones, less noise than shadows adjustment

Larger photowells allow a larger dynamic range to be captured Larger sensors with less pixels => larger photowells DynamicRange