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December Meeting Information
The December meeting of the Photoshop Special Interest Group will be held on Thursday, December 12th in room 245 of Voorhees High School, from 6:30pm until 8:30pm. The focus of the meeting will consist of sharpening images, with a concentration on Photoshop’s Unsharp Mask filter. Members who wish to have their images used as part of the demonstration should contact chairman Matt LaRusso prior to the meeting. Additionally, Steve Reiss will demonstrate a technique for coloring line art illustrations.
Raw Image Format
At the November meeting, there was a question posed about the RAW image format. A RAW file format consists of a stream of bytes describing the color information in the image without a header, which must be entered when the file is imported into Photoshop. The RAW image format is what you get if you dump the pixels of an image straight out to a file instead of to a display or printer.
Some digital cameras have the ability to shoot in RAW format in addition to the more common TIFF and JPEG formats. While a TIFF is uncompressed and will provide better quality than the best JPEG setting, it may yield a larger file than a comparable RAW image, as some cameras use a proprietary lossless (non-destructive) compression when creating a RAW image. Often, these images are only able to be opened in Photoshop with a plug-in. You may find that taking digital images in uncompressed TIFF mode is just as effective as using the raw format, and much more compatible.
Should you work with RAW images as opposed to JPEGs or TIFFs? You will have to decide for yourself if it is worth the extra storage space and processing to work in RAW mode. For most people the answer will be “no.” However, there is extensive discussion of this format in the Adobe Photoshop User Forums for those interested.
Tips and Tricks: Unsharp Mask
Since the focus of December’s meeting will be dealing with sharpening images
using the Unsharp Mask filter, it is worth repeating the following tips from
previous PSIG eNewsletters.
Sharpen Like A Pro – To bring out better detail when sharpening an image,
change the color mode to RGB, then to LAB. Then click on the channels
palette, select the lightness channel, and run the unsharp mask. Select all
the channels again, and see how much better the image looks.
No Halos – When applying the Unsharp Mask, you may notice “halos” around
parts of the image. To get around this, change the color mode to Lab, select
the Lightness channel, then apply the filter.
More Sharpening – Another way to sharpen your image is to first, make a copy
of your background layer, then go under Filter > Other > High Pass. Enter a
setting of 1.5 pixels. Now change the blend mode of the new layer to Soft
Light.
Better Sharpening – After using the Unsharp Mask, you may notice halos
around some of the colors. To get rid of this, go to Fade under the Edit
menu, set the Mode to Luminosity, and bring the percentage down until it
looks right.
Sharpening Skin Tones in CMYK – To get the best effect when sharpening skin tones in CMYK mode, apply the filter to only the Cyan channel of an image.
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