The PSD settings dialog box appears when you press the PSD settings... button on the Save Image As dialog box. It lets you control attributes of the PSD image file.
Pixel
size
Allows you to choose whether to save the file with 24-bit pixels
(8 bits per color channel) or 48-bit pixels (16 bits per color channel).
This option is available only if the image uses 45-bit pixels. See Use 45-bit pixels and Enable color tool on the Project properties dialog box to learn about 45-bit pixels.
NOTE: 16-bit layered images require Photoshop CS or newer. If you have an older version of Photoshop, you should choose the 24-bit option.
Layer cropping
Controls whether the Photoshop layer images are cropped to the
image boundaries. For more information, refer to “PSD image file format” in
this chapter.
Layer blending
Controls the blending of layer images. If you choose the blended
option, the transparency channel is used to blend the layers according to the
way that you have edited the overlap regions. The unblended option uses the
transparency channel only to define the boundaries of the warped images. If
you intend to use Photoshop’s Auto-blend layers command, you should choose the
unblended option.
Exposure and color correction
Controls how the color values are written to the PSD file. Choose
Use adjustment layers for corrections to save with the colors
shown on the screen as affected by the Color
tool settings and the Blending properties dialog box settings.
Choose
Save with uncorrected colors to save without applying any color
corrections exposure corrections. If you intend to use Photoshop’s Auto-blend
layers command, we recommend that you choose the uncorrected option or
experiment with both settings to determine which give you the best result.