How to blend two photos and compare on Mac
Combine a portrait with an autumn landscape using Multiply, then compare the original with the blended result in a split view.
- What you'll achieve
- A portrait blended with an autumn forest at full intensity, shown alongside the original in a split Before/After comparison.
- What you need
- Image Blend Modes Editor 2.0 on a Mac.
- Two photos available to open: a base portrait and a second image of an autumn scene.

Blend a base portrait with a second photo to create an autumn double-exposure effect. Follow the real macOS editor from the first image through the blend controls and finish by comparing both versions.
1.Open the blend editor
Open Image Blend Modes Editor. The starting workbench offers Open Base Image... and Open Blend Image..., with the Blend Atlas on the right.

Image Blend Modes Editor workbench with Open Base Image and Open Blend Image actions and the Blend Atlas panel. 2.Choose your base photo
Use Open Base Image... to load a portrait. The canvas shows the base image by itself, so you can check the composition before blending.

An autumn-toned portrait loaded as the base image in the Mac blend editor. 3.Add an autumn overlay
Use Open Blend Image... to add an autumn forest photo over the portrait. The canvas previews the combined images, and the inspector shows Blend Amount and Blend Atlas.

Autumn forest photo layered over the portrait, with Multiply selected and Blend Amount at 100 percent. 4.Confirm the Multiply blend mode
In Blend Atlas, choose Multiply under Darken, or confirm that its card is already selected. It can be the default when the overlay loads, so the picture may not visibly change at this step. Leave Blend Amount at 100% to match the example.

Multiply highlighted in Blend Atlas under Darken while the autumn double-exposure result is displayed. 5.Compare the original and blended photo
Enable Compare original and blend. The canvas displays a vertical split with Before on the left and After on the right. Move the divider to inspect how the autumn overlay changes your portrait.

Vertical Before and After split comparing the original portrait with its autumn forest Multiply blend.
Tips
Multiply may already be selected after you add the second photo. Check the highlighted card before changing modes.
Adjust Blend Amount if the overlay hides important details; 100% matches the illustrated result.
Use Compare original and blend to judge the effect before exporting your image.
Watch outAt 100% Multiply, dark details from the overlay can cover the face. Reduce Blend Amount to preserve more of the portrait when needed.