How to Make all Layers Visible in Final Photo?

Question

Hello, I'm new at PS and CS5. While retouching a portrait, I've created 5 layers. When the eye is open on all layers in the layers palette the only layer that seems to be active is the one on top of the list. If I move a different layer to the top, then that layer is active and the others, even though marked active, are not visible in the actual photo. I tried merging all the layers and there was no difference. What am I missing? Thanks.

Answer 1

If you're duplicating a layer to make changes, then you are duplicating all the pixels on that layer.  I don't know why a tutorial might suggest that, except perhaps to give you a point to go back to if something goes wrong.  It's important to note that such a layer, assuming you keep it at 100% opacity, will completely occlude all layers below it.
A similar technique which builds upon lower layers and does involve all layers being visible is this:
1.  Create a new, completely transparent layer.
2.  Use tools such as Clone, Fill, Paint, etc. to draw on the transparent layer (setting them to sample from layer(s) below).
In this fashion you can have the entire original image intact, yet create a derivative work that involves layers that have just the changes on them.
Again, the key here is opacity.  If a layer is transparent (or partially transparent, or parts of it are transparent), you can see through it to information from layer(s) below.
If a layer is 100% opaque and there are no "holes" erased in it or masked from it, then any layers underneath are not participating in the look of the image.  But they may still be there to provide you a handy reference for what the image looked like before changes, etc.
-Noel