Jason Johnson wrote:
> But why would you want to do this? It seems you're just basically
> flattening the image and creating a layer copy of it.

Yes, that's right. You will find out that PS doesn't exactly make it easy to preserve your steps, which can be valuable if at some later time you want to alter one or two steps. Filters are the real culprit because they cannot be applied as an adjustment layer.

For example suppose you had these layers in your layers palette:

Hue/Sat adjustment layer
Levels adjustment layer
Background

and now you want to apply sharpening. You can't apply sharpening as the next layer because PS will think you want to sharpen the Hue/Sat adjustment layer and it won't let you do that. So, one choice is to flatten your image and apply sharpening, but then you won't preserve your steps. So, what I do is use the shift+ctrl+alt+E trick to merge the layers into a blank layer on top of the layers palette, and I end up with this:

Merged layer
Hue/Sat adjustment layer
Levels adjustment layer
Background

Then, I can sharpen the Merged layer and PS doesn't complain, AND all my steps are preserved. If I want to apply different sharpening later, I delete the merged layer, remerge, and resharpen. When I am engaged in an involved retouching like the Dragan effect, I will often have to merge all the layers several times to create a composite of what has gone on before in order to be able to apply the next step.

In addition, I use some of the different merge commands when I need to use my layers palette to construct a mask. To do that, I may move a few layers to the top of the layers palette. To avoid getting confused, I will sometimes bracket the mask construction layers with blank layers. I might have something like this:


Hue/Sat adjustment layer
Curves
Levels
Background

but the Hue/Sat adjustment layer doesn't look good applied to the whole image, so I might decide to target only one area of the image. To do that, I first get a composite of what I have so far:

Merged result
(turned off visibility)Hue/Sat adjustment layer
Curves
Levels
Background

Then I will use some tricks to make a mask to target only the areas I want the Hue/Sat layer to affect(the details of which are unimportant), and I will offset the mask construction layers with blank layers to separate them from the rest of my retouching:

Blank layer--"constructed mask below"
--------------
Hue/Sat adjustment layer to use the mask thumbnail
Gradient Map adjustment layer
Merged result
-------------
Blank layer--"constructed mask above"

(turned off visibility)Hue/Sat adjustment layer
Curves
Levels
Background

Then, with those particular tricks for making the mask in the "construction zone", I need to merge two layers to get the mask on one layer, and I will use merge down or merge linked to do that. Once I have the mask on one layer, I can copy it, and then move back down to the Hue/Sat layer and paste it into the mask thumbnail on the Hue/Sat adjustment layer.

So, in that little scenario, I used the shift+ctrl+alt+E merge trick to intially merge what I had so far, and then I used the result to make a mask, and while making the mask, I used merge down or merge linked.

I hope that helps.















> But why would you want to do this? It seems you're just basically
> flattening the image and creating a layer copy of it. I'm not
> grasping some concept here for some reason or another. Ugh... I
> hate to be the slow person in class! I feel like I'm in phsyics
> all over again, LOL... straight A student until it came to that.
>
> dpnew wrote:
> > Randy E. Crisp wrote:
> > > Jason,
> > >
> > > When I merge Layers, I then SELECT ALL/COPY, then go to my HISTORY
> > > PALLETTE and then UNDO.
> > > I then can PASTE the merged LAYERS back into it if need be.
> > > That way you have an infinite amount of things you can do to the
> > > merged portion.
> > >
> >
> > Another and perhaps easier way to accomplish that is to first turn
> > off the visibility of any layers you don't want involved in the
> > merge. Then, create a blank layer at the top of your layers
> > palette. With the blank layer active, click on shift+ctrl+alt+E.
> > That will merge all visible layers into the active layer.
> >
> > > Also, the MERGE LINKED allows you to ONLY link two LAYERS, (or
> > > more) and you might have 10 showing...
> > >
> >
> > "Merge linked" allows you to merge as many layers together as you
> > want. You just have to click to the right of the eyeball icon to
> > make the link icon visible for all the layers you want to merge,
> > and then all the layers with the link icon next to them will be
> > merged.
> >
> > > I hope this helps, plus makes sense.
> > >
> > > Randy
> > >
> > >
> > >
> > > Jason Johnson wrote:
> > > > Must be a stupid question, but I'm not understanding. What
> > > > advantage is there to merging layers instead of just flattening?
> > > > When I click merge visible, or merge down, it seems to do the same
> > > > as flattening. The layers go away, and I can't seem to find how to
> > > > get them back to make adjustments to them. It seems like it's
> > > > doing the same thing as when I flatten the image. Any help? I
> > > > know this is basic, but sometimes I get hung up on the basic
> > > > philosphies of Photoshop. Sorry for the ridiculous question...
> > >
> >
>