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<ul class="navigation"><li class="prev"><a accesskey="p" class="prev" href="WSfd1234e1c4b69f30ea53e41001031ab64-78eea.html" title="High dynamic range images"><img src="images/blank.gif" alt="Previous" width="17" height="17" /></a></li><li class="next"><a accesskey="n" class="next" href="WSfd1234e1c4b69f30ea53e41001031ab64-78e5a.html" title="Merge images to HDR"><img src="images/blank.gif" alt="Next" width="17" height="17" /></a></li></ul><div class="hierarchy" id="hierarchy"><a href="WSfd1234e1c4b69f30ea53e41001031ab64-794aa.html">Opening and importing images</a> /
     <a href="WSfd1234e1c4b69f30ea53e41001031ab64-78eea.html"><b>High dynamic range images</b></a> 
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                <h1>
                    About high dynamic range images
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                <br clear="both" /><div id="minitoc"><div class="t"><div class="b"><div class="l"><div class="r"><div class="bl"><div class="br"><div class="tl"><div class="tr"><div><h3>Contents [<a href="#" onclick="return toggleMiniToc('minitoc-links', this);" class="hideLink">Hide</a>]</h3><ul id="minitoc-links"><li><p><a href="#WS741E588A-09B7-4213-8FAF-80BAE73D9E6Ba"><h1 class="topictitle1">Photoshop support for 32‑bpc images</h1>
</a></p></li></ul></div></div><br clear="both" /></div></div></div></div></div></div></div></div><br clear="both" /><div><p>The dynamic range (ratio between dark
and bright regions) in the visible world far exceeds the range of
human vision and of images that are displayed on a monitor or printed.
But whereas human eyes can adapt to very different brightness levels,
most cameras and computer monitors can capture and reproduce only
a fixed dynamic range. Photographers, motion picture artists, and
others working with digital images must be selective about what’s
important in a scene because they are working with a limited dynamic
range.</p>
<p>High dynamic range (HDR) images open up a world of possibilities
because they can represent the entire dynamic range of the visible
world. Because all the luminance values in a real-world scene are
represented proportionately and stored in an HDR image, adjusting
the exposure of an HDR image is like adjusting the exposure when
photographing a scene in the real world. This capability lets you
create blurs and other real-world lighting effects that look realistic.
Currently, HDR images are used mostly in motion pictures, special
effects, 3D work, and some high-end photography.</p>
<div class="fignone"><a href="#" onclick="return showHideImage('im_10', this);">View full size graphic</a><img alt="" id="im_10" src="images/im_10.png" /><div class="figdesc">Merging images of different exposures to create an HDR image</div><br /></div><p>In Photoshop, the luminance values of an HDR image are stored
using a floating-point numeric representation that’s 32 bits long
(32‑bits-per-channel). The luminance values in an HDR image are
directly related to the amount of light in a scene. This is not
so with (non-floating point) 16‑bits-per-channel (bpc) and 8‑bpc
image files, which can store luminance values only from black to
paper white; this represents an extremely small segment of the dynamic
range in the real world. </p>
<p>Photoshop offers layers support for 32‑bpc images, and many tools,
filters, and commands can be used with 32-bpc images. (For more
information, see below.) In addition, you can specify new images
as 32 bpc in the New dialog box. </p>
<p>You can also paint on 32‑bpc images in Photoshop. The Adobe Color
Picker lets you specify colors that have a brightness intensity
that exceeds 1.0 (the equivalent of the 255 level in an 8‑bit RGB
document). See also <a href="WSAC4AF413-1584-4733-B2ED-8FB8FF67E8BDa.html">About the HDR Color Picker (Photoshop Extended)</a>.</p>
<p>You can create an HDR image using multiple photographs, each
captured at a different exposure. In Photoshop, the Merge To HDR
command lets you create HDR images from multiple photographs. Because
an HDR image contains brightness levels that far exceed the display
capabilities of a standard 24‑bit monitor or the range of tones
in a printed image, Photoshop lets you adjust the preview of the
HDR image so it can be viewed on a computer monitor. If you need to
print the image or use Photoshop tools and filters that don’t work
with HDR images, you can convert the HDR image to an 8‑ or 16‑bpc
image. </p>
<p>For a video on editing and merging images from Lightroom, see <a href="http://www.adobe.com/go/lrvid4121_ps" target="_blank">www.adobe.com/go/lrvid4121_ps</a>.</p>
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<div id="WS741E588A-09B7-4213-8FAF-80BAE73D9E6Ba" class="nochunk"><a name="WS741E588A-09B7-4213-8FAF-80BAE73D9E6Ba"></a><h3 class="topictitle3">Photoshop support for 32‑bpc images</h3><div><div class="section"><p>Use the following tools, adjustments, and filters
with 32‑bpc HDR images:</p>
<dl><dt class="dlterm">Adjustments</dt>
<dd>Levels, Exposure, Vibrance, Hue/Saturation, Channel Mixer,
Photo Filter.<div class="note"><span class="notetitle">Note:  </span>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.</div>
</dd><p class="dlseparator"></p><dt class="dlterm">Blend Modes</dt>
<dd>Normal, Dissolve, Darken, Multiply, Lighten, Color Darken,
Linear Dodge (Add), Color Lighter, Difference, Hue, Saturation,
Color, and Luminosity.</dd><p class="dlseparator"></p><dt class="dlterm">Create new 32‑bpc documents</dt>
<dd>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.</dd><p class="dlseparator"></p><dt class="dlterm">Edit menu commands</dt>
<dd>All commands including Fill, Stroke, Free Transform, and Transform.</dd><p class="dlseparator"></p><dt class="dlterm">File Formats</dt>
<dd>Photoshop (PSD, PSB), Radiance (HDR), Portable Bit Map (PBM), OpenEXR,
and TIFF.<div class="note"><span class="notetitle">Note:  </span>Although Photoshop cannot save an HDR image in
the LogLuv TIFF file format, it can open and read a LogLuv TIFF
file.</div>
</dd><p class="dlseparator"></p><dt class="dlterm">Filters</dt>
<dd>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.</dd><p class="dlseparator"></p><dt class="dlterm">Image commands</dt>
<dd>Duplicate, Image Size, Canvas Size, Image Rotation, Calculation,
Variable, and Trim.</dd><p class="dlseparator"></p><dt class="dlterm">View</dt>
<dd>Pixel Aspect Ratio (Custome Pixel Aspect Ratio, Delete Pixel
Aspect Ratio, Reset Pixel Aspect Ratio, etc.)</dd><p class="dlseparator"></p><dt class="dlterm">Layers </dt>
<dd>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.</dd><p class="dlseparator"></p><dt class="dlterm">Modes</dt>
<dd>RGB Color, Grayscale, conversion to 8 Bits/Channel or 16
Bits/Channel.</dd><p class="dlseparator"></p><dt class="dlterm">Pixel Aspect Ratio</dt>
<dd>Support for square and non-square documents.</dd><p class="dlseparator"></p><dt class="dlterm">Selections</dt>
<dd>Invert, Modify Border, Transform Selection, Save Selection
and Load Selection.</dd><p class="dlseparator"></p><dt class="dlterm">Tools</dt>
<dd>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.</dd><p class="dlseparator"></p></dl>
<p>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.</p>
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