Just wanted to share that I finally got my head around 'layers' and 'masks' .. thanks to the instructional materials at http://www.photoshopelementsuser.com

Here's my before-shot ...

And here's my after-shot ...

I created a layer to darken the outdoor-through-the-window area, a layer to lighten the side-rear interior of the restaurant, and another layer to tone down the brightness of the foreground table-top. I used the polygonal lasso, paint-bucket and brush tools to white-reveal-through the three layers' masks.

I'm sure that for those who've already been using layers and masks, this is no big deal. But for years I've been applying permanent changes to file copies .. always failing to grasp the 'layers-masks' process. It was only when I read the instructional materials at the above website, that the 'penny-dropped'! So, I thought I'd share!