Using Merge to HDR in Photoshop

Here are the steps followed to
get the final result.
1. Set your camera up on a tripod to hold it steady for the individual shots. The photos must be
as close to identical—other than exposure—as possible.

2. Prepare to take two or three photos at different exposures times. You should vary the shutter
speed, rather than the lens opening, because changing the aperture will modify the depth-offield
and may change the apparent size of some components of the photo, such as points of light.
If your camera has a bracketing command, you can use that to change the shutter speed between
shots only if your camera allows relatively large exposure increments, such as 1 EV between
bracketed shots. Generally, most cameras bracket using smaller 1/2 or 1/3 EV steps that are not suitable
for Merge to HDR.


3. Make the individual photos at least one or two EV steps apart, such as 1/60th second for the first and
1/250th second for the next, and perhaps 1/15th second for the third. Smaller increments will provide
little extra information for Merge to HDR to work with; larger increments may create photo
sets that are so far apart in exposure that there is not sufficient overlap to produce a smooth tonal
range.

4. Save in RAW or TIFF format in your camera so you’ll get full-range, 16-bit/channel images,
rather than the 8-bit/channel images created by JPEG. However, if Merge to HDR works with 8-
bit/channel images, it will combine them into one new 16-bit/channel image using the HDR
capabilities.

5. If you use an application to transfer the files to your computer, make sure it does not make any
adjustments to brightness, contrast, or exposure. You want the real raw information for Merge to
HDR to work with. You’ll end up with two photos.

6. Activate Merge to HDR by choosing File >Automate > Merge to HDR.

7. Select the photos to be merged.


8. Once Exposure merge has done its thing, you must save in .PSD, .PFM, .TIFF, or .EXR formats
to retain the floating-point data, in case you want to work with the HDR image later. Otherwise,
you can convert to a normal 24-bit file and save in any compatible format.