We can use different Opacity (or transparency) levels for different images to create cool overlap morphing effects. We have already seen that during image morph, merge & overlap Photoshop tutorial. Here is back to basics for Photoshop starters to master the technique of varying opactity levels while using multiple images.
Change Opacity levels of images & objects
1. Open Photoshop, goto File > New & click OK. A new blank canvas will open.
2. Now you need to open 2 images in Photoshop. Goto File > Open and then load 2 different images in Photoshop application.
3. Then you need copy these images on the new blank canvas as opened in step 1. Select the image by pressing Ctrl + A keys and then press Ctrl + C to copy whole image. Then click on blank canvas to highlight it and press Ctrl + V to paste the image. Similarly, paste 2nd image on the canvas.
4. Now you will have 2 images on the canvas as displayed by layers window as seen in above screenshot.
5. Click & move slider next to Opacity to reduce opacity of the either of image on the canvas. You can play around with opacity levels of both images. Also, arrange which image should be at top or bottom by arranging them with mouse drag in the layers window.
You can follow similar above steps to change opacity levels of different objects. Just move the opacity slider around for different layers of respective object shapes.