The black object is reflecting almost no light, appearing almost black (typically a value of 3% is used). Imagine a white object, a gray object, and a black object being photographed side by side. The white object is bouncing back close to 100% of the light that shines on it (for calculating middle gray, the value of 95% is typically used).
In real-world photography, the situation can be just as complicated. Again, middle gray is relative and not absolute. This still doesn’t give you complete consistency, because the 50% value may be brighter or darker in certain color spaces. If black is represented as 0, 0, 0 in RGB values, and white is 255, 255, 255, then middle gray is 128, 128, 128.
WHITE BALANCE IN EXPOSURE X SOFTWARE
In software like Photoshop, middle gray represents the midway point in RGB (or CMYK, LAB, etc.) values. Now that we understand what role middle gray plays in photographing a scene, the next obvious question is why do photographers refer to middle gray as some value other than 50%? If middle gray is the value between white and black, why isn’t it just halfway between those two values? Furthermore, where do these percentages even come from? Today’s default matrix/evaluative/multi metering mode also takes into account more advanced information compared to metering modes of the past, and it’s less likely to fail in situations like a snowy landscape.įor more on metering modes, check out our guide to Understanding Metering and Metering Modes. For instance, spot metering only pays attention to a small region of the frame, usually your focus point, so the “person on a stage” example would be properly exposed. Exposure compensation lets you manually shift the metering target to be brighter or darker, essentially shifting the camera’s target for middle gray.Īlternate metering modes can give you the same result.
WHITE BALANCE IN EXPOSURE X MANUAL
To address these issues, either manual changes to exposure, called exposure compensation adjustments, or alternate metering modes, have to be used. A scene that should appear significantly brighter than middle gray is underexposed, appearing far darker than snow should. In contrast, taking a photograph of a bright, snow-covered landscape poses the opposite issue. In this case, if the meter is trying to bring most of the scene to middle gray, the stage will appear too bright, and the person will be overexposed. Consider photographing a person on a stage, lit by a bright light, but with the rest of the stage being significantly darker. This can cause a number of problems with certain subjects, and you may have already run into these issues. If the camera can get most of the scene to be about middle gray in brightness, it’s less likely that your photo is either overexposed or underexposed. Modern metering systems have more complex modes that take subject recognition and other factors into account, but there’s still a bias for exposing the overall photo toward middle gray. Middle gray serves as a good, but simplistic, target for metering just because it’s in the middle. It serves as the target for manual metering, and later represented the target for automatic metering systems.
In Ansel Adams’s famous Zone System, middle gray is represented by Zone V. There is not one specific tone of gray that is universally agreed upon to be “the middle,” and it ultimately depends on context. Middle gray is therefore the tone in the middle of that range. For photography, a subject in your frame can be completely white, completely black, or something in between. To start, let’s take a look at what middle gray actually is.
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