Digtal Printmaking with Richard Wohfeiler
A. Open App., Under Edit, select 'color settings', and ensure that RGB= Adobe RGB (1998) rather than sRGB... (websafe crummy default... microsoft's fault). If your document doesn't match your colorspace, you want to know that. Most inkjet printers invert the RGB to CMYK automatically, so you don't wanna work in CMYK as that would cause it to invert the colors twice and fuck everything up. Further explanation of how colorspaces work under 'colorspaces' on Wikipedia. In short, even nice devices (printers, monitors, projectors) don't display the full range of visible color. Not even close. The goal of 'colorspaces' is to help you make the gamut of color on your scanner, your monitor, and your printer to be as closely related as possible.
B. If you convert a file that you have saved in Adobe RGB to sRGB you will lose the colors that are outside the gamut of sRGB.
C. the Photoshop CS3 textbook has more information regarding colorspaces in chapter 1 (p. 30, 36)
A. read CS3 'intro to pixels' section.
B. A pixel has no set spacial size. The resolution of the image is determined by the pixel dimensions given the size of canvas. Thus 300 by 200 pixels on a 3" by 2" canvas has a 100 dpi (dots per inch) resolution.
C. The epson inkjet printers like to receive images in around 400 dpi.
D. When you increase the pixel dimensions of a document without changing the document size, photoshop inserts pixels between each of the old ones (called pixel interpolation). This would, of course, increase the disk size of the document.
E. If you check 'resample image' in the image size dialog box while resizing an image, photoshop will lock your resolution to match your original image. This means that photoshop does a better job at guessing the color information of the interpolated pixels.
F. Generally you should follow resizing/ resampling with a round of careful 'sharpening'. Use one of the sharpen dialog boxes ('unsharpen mask', 'smart sharpen tool') rather than the preset 'sharpen image'. Sharpen can act as an excellent filter tool on its own. It is especailly useful when printing on uncoated papers: an oversharpened image will look nice and sharp when printed on uncoated paper (bfk, rice paper, arches, etc.)
A. Richard uses Silverfast image importing software. Search for an opensource equivalent? Otherwise, the scanners always have software, or you should be able to use apple's 'image capture' app.
B. 'Bit Depth'refers to how many bits per color channel. Printers now will actually print in 24 or even 48 bit depth instead of 8 bit that was standard for many years.
C. Use a resolution that is a even factor of the maximum possible resolution of the scanner. ie, 4800 max means that 300, 400, 600, 800, 1200, 2400 dpi are good scan resolutions.
D. If you want to print say a 4" by 5" photo at 8" by 10", you need to at least double the resolution. Doubling the resolution will quadruple the disk size of the document. And take that much longer to scan. BUT it means that you are getting that much more real information about the image (much better than resampling the image after the fact).
A. Try not to save as .jpeg: every time you save a jpeg you are compressing the file. Over time, this can result in serious distortion as well as loss of color). Save files as .psd or .tiff or .pdf off the bat (from the printer, or as soon as you pull image off the camera, etc.).
Now that the image from the scanner has been imported, there are no doubt imperfections.
A. First use the 'dust and scratches' tool under 'filter'---->Noise... A greater radius will mean that more dust is filtered out, but that will also over soften the image. B. You can also pull out dust and scratches with the 'heal' tool (on CS2 we had to use the rubber stamp, but heal is better and lots faster--no sampling required).
Day Four: First Crit. 10/8/08
Stephanie SyjucoBlu
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