Evaluating Originals
Whether photographic, artwork or electronic, originals must be evaluated for suitability for reproduction.
- Standard light sources should be used when viewing hard copy originals.
- Should use the Info palette (“software densitometer”) in Photoshop to examine specific RGB and CMYK values.
- Sharpness may need to be adjusted using the unsharp masking and sharpen tools in Photoshop. Sharpness is difficult to evaluate in displayed images. Use zoom tools (2:1 is good) to identify lack of sharpness.
- Color Balance may need to be adjusted to remove a color cast, which may be objectionable. Check white points and neutral gray regions for balance.
- RGB values should be equal and CMY should be in roughly 5:4:4 ratio.
- Color casts can be removed in Photoshop.
- Contrast adjustment may be necessary for colorful and appealing pictures.
- Color contrast depends on the saturation of individual colors. Too much or too little contrast may detract from quality of image.
- Overall lightness should vary from roughly 5% to 95 %, with some specular highlights (small areas corresponding to light source or bright reflection) being close to 0%.
- Tonal gradation may need to be examined. Look for good separation between areas of detail (5-10%) and smooth transition between tones (<2%) in continuous regions.
- Grain may be visible in original, possibly under magnification. Despeckle filter in Photoshop may remove visible grain.
- Blemishes need to be removed from scanned originals. May result from dust, fingerprints, scratches etc.
Image Retouching - Now frequently done electronically. This provides ease, speed and power while leaving the original intact.
- Image editing software such as Photoshop combine functions of photographer, artist, retoucher and electronic prepress