HDR Photography: How to Tone Map in Photoshop
Tone mapping high dynamic range images in Photoshop is much more streamlined than in an application like Photomatix Pro, essentially because you have so few options. Your main decision is to choose one of the four tone mapping methods, two of which don’t have any settings.
To tone map an HDR image in Photoshop, follow these steps:
Have your HDR image ready.
You can load a previously saved HDR image or continue directly from creating the HDR image.
If necessary, perform adjustments on the HDR image.
Photoshop allows you to perform limited adjustments on 32-bit HDR images. Be careful! What you see onscreen is not a completely accurate representation of the actual image unless you have a 32-bit-per-channel HDR monitor.
If you’re feeling adventurous, choose Image→Duplicate.
This sets up more than one copy of the HDR image so you can experiment and apply a different conversion setting per duplicate image. You can switch back and forth between images to compare the effects of different methods and settings.
Choose Image→Mode→8 Bits/Channel or Image→Mode→16 Bits/Channel to lower the bit depth.
This opens the HDR Conversion dialog box, where you select the tone mapping method you want to use.
Alternatively, you can jump from the Merge to HDR dialog box directly to the HDR Conversion dialog box if you select a lower bit depth than 32 bits-per-channel when merging to HDR.
Choose a tone mapping method from the Method drop-down list and then experiment.
Alter settings, switch methods to compare results, and experiment to decide the appropriate method and settings for your image.
You may also load settings from previous sessions (provided that you saved them). If you’re working on several HDR images of the same subject (say, an interior), create a master setting to save, and then apply to the additional HDR images of the same scene.
Process the image by clicking OK to apply the tone mapping settings.
Save the low dynamic range result by choosing File→Save.
You can continue to edit this file (reducing noise and such). Make sure to save your final results.