onsidering tất cả những điều không thể tin được, bạn có thể làm trong Photoshop, bạn có thể dễ dàng quên những điều cơ bản. Có, bạn có thể tạo ra tác phẩm đáng kinh ngạc với các hiệu ứng đặc biệt, nhưng những người nhìn màu xanh làm giảm hình ảnh. Nhận được trong các thói quen tốt, hình ảnh sạch sẽ trước khi đi vào bộ lọc artsy và những điều thú vị. | 456 Book ỈV Photoshop CS5 Chapter 7 Creating a Good image ỉn This Chapter Understanding the histogram Getting ready to correct an image Making a good tone curve Editing adjustment layers Testing your printer onsidering all the incredible things you can do in Photoshop you can easily forget the basics. Yes you can create incredible compositions with special effects but people who look greenish detract from the image. Get in the habit of building good clean images before heading into the artsy filters and fun things. Color correction isn t complicated and if it s done properly produces magical results in your images. In this chapter you see how to use the values you read in the Info panel and use the Curves panel to produce quality image corrections. Reading a Histogram Before making adjustments look at the image s histogram which displays an image s tonal values to evaluate whether the image has sufficient detail to produce a high-quality image. In Photoshop CS5 choose Window Histogram to display the Histogram panel. The greater the range of values in the histogram the greater the detail. Poor images without much information can be difficult if not impossible to correct. The Histogram panel also displays the overall distribution of shadows midtones and highlights to help you determine which tonal corrections are needed. Figure 7-1 shows a good full histogram that indicates a smooth transition from one shade to another in the image. Figure 7-2 shows that when a histogram is spread out and has gaps in it the image is jumping too quickly from one shade to another producing a posterized effect. Posterization is an effect that reduces tonal values to a limited amount creating a more defined range of values from one shade to another. It s great if you want it but yucky if you want a smooth tonal change from one shadow to another. 458 Reading a Histogram Figure 7-1 A histogram showing smooth transitions from one color to another. Figure 7-2 A histogram showing a lack of .
