Photoshop CS6 provides a couple different ways to create HDR photos. HDR stands for High Dynamic Range photography, and provides a useful workaround for high contrast scenes that extend beyond the dynamic range of most cameras. Down the road HDR may become a common capability for all cameras, but for now even with expensive DSLRs, the quality of in-camera HDR processing is generally not the best option.
32-bit HDR Toning is a specific kind of HDR workflow in Photoshop that allows you to create a 32-bit 'base image' from a series of exposures, and then use the HDR Toning image adjustment to map the data in the original exposures into a 16-bit shot ready for editing. This process offers a 32-bit alternative to the 8- and 16-bit toning options inside Merge to HDR Pro, but you still need to start there.
First, choose File Automate Merge to HDR Pro. From this dialog you can select the raw exposures you'd like to include in the HDR Toning process. Make sure you choose to align them before you click OK. Photoshop may take a minute or two to bring all the shots together.
Once the Merge to HDR Pro window opens, you will see a large preview of your photo, along with several thumbnails (bottom left) and some controls (top right). For this workflow we only need to do three things in this window:
From the Mode menu choose '32-bits'. This will force the Local Adaptation option, and give you a single White Point control.
Use this control to remap the pixels so that you control the point at which the detail turns white. Use the histogram to give you an idea of how far to move the slider.
Turn on Remove Ghosts, and click any of the thumbnails at the bottom of the screen, to select the shot that is used to make everything in the shot 'still'. Typically you'll want to use one of the darker shots (i.e. the faster exposures). In this case I was able to use one of the brighter exposures; the only thing moving was the water which should be blurred anyway.
When you're done with the 32-bit steps, click OK and Photoshop will merge the raw file data together and create a single 32-bit document. This might also take a minute or two depending on image size and available computing power.
After your 32-bit image opens in Photoshop, you need to follow a particular set of steps to get to the HDR Toning dialog, so that you only have to use the controls once when converting (ultimately) to a 16-bit document. Instead of choosing the HDR Toning adjustment directly (which would force us to pass through it a second time later when crunching down to 16-bit for retouching), choose Image Mode 16-bits/Channel. This will open the same HDR Toning dialog, which shares many controls with Merge to HDR Pro. The list below describes how each works.
Edge Glow: These sliders control the HDR 'glow' and halo effects you may be familiar with from HDR web sites and galleries, by manipulating local contrast. These are most often the 'culprit' when an HDR image looks 'fake' or 'illustrated', rather than captured with a camera.
Smooth Edges: This is new in CS6 and helps to reduce halos and other types of edge artifacts when increasing the detail level in the shot.
Tone and Detail: These sliders allow you to set the overall brightness level. Use Exposure to achieve the correct amount of ambient light, then, if many of the highlights become heavily clipped, decrease the Gamma slightly to recover some of those tones. The Detail slider enhances local contrast, much like the Clarity slider in ACR. Remember: a little bit goes a long way!
Advanced: The Shadow and Highlight controls also work like their counterparts in ACR and Lightroom, opening up shadow details and unclipping blown out highlight details, respectively. If the image is too flat, they can also be used to push the darker and lighter tones towards pure black and white, respectively. The Vibrance and Saturation controls enhance the global color intensity. Use Vibrance alone, if you can get the desired effect.
Toning Curve: Allows you to fine-tune the contrast beyond what the Tone and Detail controls can do using a corner point tone curves. May not be required in all cases.
I usually work with Exposure, and then the Gamma and Highlights sliders first, in order to set the global brightness of the image, and recover any lost highlights details. For this shot, I boosted the Exposure value by about a half a stop to recreate an accurate level of ambient light for the scene, and then I reduced the Highlights value to make sure none of the splashing water was clipped to pure white.
The Detail level was actually decreased a bit to enhance the smoothness of the waterfall effect. To improve global contrast, I also reduced the Shadows value to clip the details under the rock to pure black. Finally I gave the Saturation control a boost to make the green moss in the image pop more, and Vibrance to warm up the fallen leaves.
Once I got the exposure and details right, I experimented with modest increases to the Edge Glow settings and smoothness setting. Note pushing these values a lot will tend to brighten up and blow out highlights in the image.
When you're finished, click the OK button to process the HDR Toning image adjustment. When the process is done you will have a 16-bit image ready for retouching. Unfortunately, this technique cannot be used with Smart Object layers for the time being, it must be used on a Flattened image.
Notice in this case the specular details on the wet boulder in the lower left corner (the light is reflecting off without clipping, and the vibrant glow of the leaves). The detail and color seen here is a good indication of a sound conversion from HDR Toning; it is a good representation of the actual scene rather than a 'grungy', hyper-contrast situation we often see on photography sharing sites.
If you enjoyed this tutorial, please check out my brand new HDR course, which also covers Lightroom and Plugin techniques (the videos above are a demo from this course).