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Photoshop cs5 cho nhiếp ảnh gia part 5

Exposure Nếu bạn kiểm tra các biểu đồ và thấy rằng bạn có một cành ở phía bên phải và phòng bên trái, bạn cần phải sửa đổi tiếp xúc của bạn để có ánh sáng ít hơn. Nếu bạn đang chụp trong Aperture Priority, bạn có thể chọn để đặt ở một số đền bù trừ phơi sáng, hoặc nếu bạn đang sử dụng chế độ hướng dẫn sử dụng, hoặc sử dụng một khẩu độ nhỏ hơn hoặc tăng tốc độ chụp của bạn. . | the clouds. Of course if you are shooting a silhouette a spike at the left side of the histogram indicating black for the silhouette is acceptable while any specular highlights may be fine as pure white. Specular highlights are those extremely bright areas that occur when the sun reflects off water or metal or other highly reflective surfaces. We expect those areas to be pure white without detail. But for most images in order to capture detail in both the shadows and the highlights you want the tonalities to fall within the boundaries of the histogram. Note Some photographers new to digital and Photoshop think they don t have to worry about exposure anymore because they can fix it later in Photoshop. The harsh reality is if you blow out the highlights or totally block up the shadows the only fix will be to clone in pixels from other areas. Photoshop gives you lots of ways to tweak the exposure which we ll explain in Chapters 3 Adobe Camera Raw and 6 Exposure Adjustments but if the data isn t there because of overexposure or underexposure Photoshop isn t going to create it for you. 20 CHAPTER 1 THINKING DIGITALLY Exposure If you check the histogram and see that you have a spike at the far right and room on the left side you need to modify your exposure to have less light. If you are shooting in Aperture Priority you may choose to put in some minus exposure compensation or if you are using manual mode either use a smaller aperture or increase your shutter speed. Because you re shooting digitally you have a third option to switch to a slower ISO. Although you still need to set the correct exposure you can use the same depth of field aperture setting as you originally wanted perhaps in an effort to keep the background out of focus and or the same shutter speed perhaps in an attempt to blur your subject . Similarly if the histogram is indicating a spike at the black end and has room on the right side you ll want to add light via plus exposure compensation slower shutter