How to Make an HDR in Photoshop CS3

HDR is short for "High Dynamic Range." An HDR image is a composite of multiple exposures of the same shot. As a result, the image has more dynamic luminance between light and dark areas because it retains all the details from each exposure. Photoshop CS3 includes a handy tool to allow you to create HDR images if you have at least three identical images of differing exposures. A tripod is recommended for optimum results, but if you don't have a tripod, you can set your camera on a firm surface and take care not to move it between shots.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Three identical photos

1. 
    
   The HDR screen showing the three combined photos and resulting HDR image.

   Take at least three identical photos, using a tripod or other secure mount to ensure that your camera is as still as possible. One image should have a normal exposure setting, one should be two exposure values (EV) underexposed and the third should be two EV overexposed. Aperture, flash and ISO for all photos should be consistent.

2. Load your photos into Photoshop. In the file menu, choose "File > Automate > Merge to HDR."

3. Choose "Add Open Files" and check the box for "Attempt to Automatically Align Source Images." Click "OK."

4. Examine the result of the merged images. You may choose to turn one of the images off if desired, as well as tweak the white point with the slider. Adjust the image until you are satisfied with the result.

5. Choose "32 Bit/Channel" from the drop-down menu and click "OK."

6. Save your image as a 32-bit file with an HDR extension. That way, you will retain all the HDR information should you wish to adjust the image in the future.

Tips & Warnings

• Only a 32-bit image will store all of the HDR information. If you want to be able to use the full range of available Photoshop tools to further adjust your image, you will need to convert it to 16 bit. To convert, choose "Image > Mode > 16/Bits Channel." A dialog box will appear allowing you to adjust settings. Some cameras have an autobracketing option that will automatically take three images (or more) of differing exposures. This is ideal for handheld shots. Set to at least 2 EV difference for each image.

References

• Adobe Photoshop CS3 Help Resource Center - Merge to HDR