Blending two photos seamlessly can be achieved using a gradient and layer masking technique. Begin by placing your two images in layers, one on top of the other, in your photo editing software. Instead of directly creating a mask, draw a rectangle shape over the top image.
Apply a gradient to this rectangle. Use a solid color, such as black, for both the top and bottom nodes of the gradient. Initially, this will result in a solid black rectangle. However, adjust the opacity of the top node to 0%. This creates a gradient transitioning from solid black at the bottom to fully transparent at the top.
Next, make this rectangle a child layer of the top image. You can do this by dragging the rectangle layer beneath and slightly to the right of the top image layer until a horizontal blue line appears, indicating it’s now nested. Alternatively, select the rectangle layer and choose “Move Inside” from the Arrange menu.
With the rectangle now a child layer, change its blend mode to “Erase”. Because it’s a child of the top image, this blend mode will only affect that specific layer. The “Erase” mode will remove the portions of the top image covered by the visible (black) part of the gradient, revealing the image underneath.
The advantage of this method is the gradient remains adjustable. You can modify its position or opacity at any time to fine-tune the blend between the two photos.