A lot of the success of the super-imposition relies on the quality and similarity of the two original photos. Try and get ones where the two people are matching in pose or looking in the same direction at least, and if possible try and get photos taken in similar lighting conditions.
Once you have your photos, play around with brightness, contrast, hue and saturation settings to make them as similar as possible in terms of light and color. You also need to make sure they are vaguely similar in size and resolution (or that the face to be superimposed is as good or better quality than the picture you're putting it onto)
Now, with a steady hand, use the lasso tool to draw a selection around the face you want to cut out. Feather the boundary of the selection to something like 5px to give a smooth graded edge. Now copy and paste the face into your new picture.
Use the transform tools to try and align the perfectly in size and shape with the picture below. It helps to make the layer slightly transparent so that you can see where the old face lay.
Once its in place, use the eraser on a low pressure to clean up any rough edges to your face.
Now just play around with the color settings again, perhaps using the spotlight filter to try and match the face on top exactly to the background.
To get it looking really good, you will probably have to make use of the rubber stamp and paintbrushes to blend the areas between the new face and the old body. You may find it helps to flatten the layers down into one image to blend them better.
Getting it perfect just takes a lot of practise, and most importantly, finding two matching images in the first place.
Hope this is some help
Nick (Webmaster)
