Frequently Asked Questions

General

Printing

Scanning

Image Editing

Image Editing

How do I properly sharpen an image in Photoshop?

It is important that sharpening is only applied to the Lightness channel so colors are not effected:

• The image should sized for printing at 180 to 360 dpi.
• Select Filter/Sharpen/Unsharpen Mask.
• Adjust the sharpness parameters without over-sharpening. Typical values are 100% to 200%, 1 pixel to 2 pixels radius, and a level 5 threshold. Higher threshold levels leave big flat areas alone.
• After applying the sharpening, go into Edit/Fade Unsharp Mask, adjust opacity, and set mode to Luminosity.

This method yields results similar to sharpening the L channel in Lab but without the image and layer loss. If you want to preserve your raw image, always apply sharpening to a duplicate image layer.

What is saturation?

Saturation is a measure of purity of a color. In terms of RGB values, saturation amplifies the separation of the values. Desaturation decreases the separation moving a color closer to gray which has equal R, G, and B values.

How do I color balance my image in Photoshop?

If your image has been scanned or digitally photographed with a standard grayscale swatch, you can check that the RGB values are balanced. Each of the values R, G, and B of the swatch should be nearly the same, thus reflecting a balanced gray.

Zoom in to the area containing the swatch. Set your sampling tool options to an area of 5x5 pixels. Hold the cursor over the white box of the swatch. The RGB values should be approximately 250, 250, 250, almost a pure white. Note that the Info tab shows values separated by a slash, these reflect the current and new values of the adjustment.

If there is much variance, adjust each channel independently by using the far right sliders in Levels. Now check a box near the dark end of the swatch. It should read something near 20, 20, 20, almost pure black. Adjust levels using the far left slider. Finally, check the middle boxes of the swatch and adjust these with the top center slider in Levels.

Why convert and work in RGB instead of CMYK?

We prefer files to be in the RGB (Red, Green, Blue) color mode instead of CMYK (Cyan, Magenta, Yellow, Black) because all digital files are captured via native RGB devices. CMYK transformations should be the last step of any printing workflow to assure color fidelity and accuracy in the final prints. These RGB to CMYK color transformations are better handled by software that resides on each printer. Simply put, the less color transformations, the better the color accuracy.