What are the practical differences between using layer opacity vs. layer fill? Anyone have an example where you would want to use one rather than another? It doesn't seem to make any difference on blending, at least what I've done. (Photoshop CS2).
thanks

Opacity affects all of the layer including layer effects.

Fill only affects the layer content, but not layer effects.

SWAMP (nothing effects me)

OK, I'll try that out. Would this be visible even with a simple effect like gausian blur?

Gaussian blur isn't a layer effect -- at least not on my version of Photoshop.

Okay, I created a new doc, made it a pale blue, made a new layer, and a medium brown box on the new layer. By making the FILL 0%, you cannot see the box. But you can apply layer FX and Styles - and they will be seen. The invisible box has a purple Stroke and a huge Drop Shadow applied to it.

Does it make sense now?

There are MANY cool tricks you can do by using this technique - one thing is to create water droplets by using layer styles, and you can save the style to repeat later.

Hope this helps-
-Lew ;-)

BTW - forgot to mention, if you made the OPACITY 0%, then you would see noting on the layer at all. Nothing you drew, filled, no layer styles and FX, nothing. It makes the entire layer and everything applied to it invisible.

So what's the point of Layer Opacity if it just makes it invisible? There 1-100% visibility - often you will turn the Opacity down to make that layer less obvious/more subtle.

Again, hope that helps-
-Lew ;-)

Thanks, that is cool. I've used layer opacity a lot in compositing images (I'm a Poser poser :) ), but hadn't figured out the difference between the fill and opacity. Now it makes a lot more sense.