Built into the panel is the ability to Auto Blend up to 7 images using three different blending methods.
There are several tools available to us in this row of the panel. The “Load Stack” button calls up the Load Files Into Stack script built into Photoshop. This allows you to select the images directly from a file directory and will load all of the images as a stack in a single Photoshop file. The “Auto Align” button is used if you believe there may have been movement between your frames during shooting. Photoshop will attempt to align the images up, which is important for Manual or Automated blending.
There are a few important things to note if you are going to use the “Auto Blend” Button. Firstly any layers that are not a part of the blend, including adjustment layers, must be turned off. Any layers that are turned off, must be moved to the top or bottom of your layer stack. Your images must be order from the darkest exposure at the top of the layer stack to the lightest exposure at the bottom of the layer stack. If you press the information button next to the “Auto Blend” button it will explain this process as well.
Once you press the Auto Blend button you will be prompted to make two selections, the amount of images you want to blend and the method that you want to use for blending. The Semi Auto and Semi Auto Reverse methods both use Luminosity Masks and will prompt your for some user input during the blending process. At each layer in the blending process you will be able to adjust the blend, creating a natural final result. The third method “Blend If” is fully automated and requires no user input. You can then go into each of the layer and adjust the opacity to modify the finished blend.
If you want to undo and retry the blend, or try a different method, use the “Undo Blend” button. You will be prompted for the number of images and the type of blend you want to undo. Make your selections and press execute to undo the previous blend.
The video below will show how to use Auto Blending in more detail.