Adobe Photoshop CS4 - Manual (Page 80)

73 USING PHOTOSHOP CS4
Opening and importing images
Last updated 1/10/2010
Photoshop support for 32-bpc HDR images
Use the following tools, adjustments, and filters with 32-bpc HDR images:
Adjustments Levels, Exposure, Hue/Saturation, Channel Mixer, Photo Filter.
Note: Although the Exposure command can be used with 8- and 16-bpc images, it is designed for making exposure
adjustments to 32-bpc HDR images.
Blend Modes Normal, Dissolve, Darken, Multiply, Lighten, Color Darken, Linear Dodge (Add), Color Lighter,
Difference, Hue, Saturation, Color, and Luminosity.
Create new 32-bpc documents In the New dialog box, 32 bit is an option in the bit depth pop-up menu to the right of
the Color Mode pop-up menu.
Edit menu commands All commands including Fill, Stroke, Free Transform, and Transform.
File Formats Photoshop (PSD, PSB), Radiance (HDR), Portable Bit Map (PBM), OpenEXR, and TIFF.
Note: Although Photoshop cannot save an HDR image in the LogLuv TIFF file format, it can open and read a LogLuv
TIFF file.
Filters Average, Box Blur, Gaussian Blur, Motion Blur, Radial Blur, Shape Blur, Surface Blur, Add Noise, Differences
Clouds, Lens Flare, Smart Sharpen, Unsharp Mask, Emboss, De-Interlace, NTSC Colors, High Pass, Maximum,
Minimum, and Offset.
Image commands Duplicate, Image Size, Canvas Size, Image Rotation, Calculation, Variable, and Trim.
View Pixel Aspect Ratio (Custom Pixel Aspect Ratio, Delete Pixel Aspect Ratio, Reset Pixel Aspect Ratio, etc.)
Layers New layers, duplicate layers, adjustment layers (Levels, Vibrance, Hue/Saturation, Channel Mixer, Photo
Filter, and Exposure), fill layers, layer masks, layer styles, supported blending modes, and Smart Objects.
Modes RGB Color, Grayscale, conversion to 8 Bits/Channel or 16 Bits/Channel.
Pixel Aspect Ratio Support for square and non-square documents.
Selections Invert, Modify Border, Transform Selection, Save Selection and Load Selection.
Tools All tools in the toolbox except: Magnetic Lasso, Magic Wand, Spot Healing Brush, Healing Brush, Red Eye,
Color Replacement, Art History Brush, Magic Eraser, Background Eraser, Paint Bucket, Dodge, Burn, and Sponge.
Some tools work with supported blend modes only.
To work with certain Photoshop features, you can convert a 32-bpc image to a 16-bpc or an 8-bpc image. Do a Save
As and convert a copy of the image file to preserve the original.
Take photos for HDR images
Keep the following tips in mind when you take photos to be combined with the Merge To HDR command:
• Secure the camera to a tripod.
• Take enough photos to cover the full dynamic range of the scene. You can try taking at least five to seven photos,
but you might need to take more exposures depending on the dynamic range of the scene. The minimum number
of photos should be three.
• Vary the shutter speed to create different exposures. Changing the aperture changes the depth of field in each
exposure and can produce lower-quality results. Changing the ISO or aperture may also cause noise or vignetting
in the image.
• In general, don’t use your camera’s auto-bracket feature, because the exposure changes are usually too small.