I know I can cut the moon out and paste it on the other image... I was just hoping I could get the true double exposure feel to it that I get in Photoshop (it is also amazingly easy).
Oh... HAH! I got it! I don't know what I did wrong before. You go to the top layer and select layer, properties, then on the dropdown menu use SCREEN. Maybe I didn't try screen. I used a couple others that almost did it, but screen was the way to go.
OK, here is the moon picture I used... I placed the moon in the upper right corner of the pic because for the project I needed to try and make it as true as possible to what I would need to make a film double exposure.
Then I added a new layer with my building.
It does not seem to matter which layer is on top. Just make sure you have the top layer highlighted, then go up to the toolbar and select 'layer-properties' and in the box that opens, on the dropdown menu that says 'normal', select 'screen' and you're all set. It IS as easy as it was to do in Photoshop! Woo hoo! I'm geeked!
Thanks for being patient w/a newbie! I DID search through, but I didn't find anything that referenced 'double exposure' and this is exactly what to do. VERY easy and cool.
Here's another one same moon, same building, different time of day:
Notice how the moon changes just slightly... not as yellow, not as much contrast. This is EXACTLY what I was looking for.