Since there is a need for two layers. I am, using one of the pictures that you posted... The bird with the crazy artifact (Still trying to figure it out by the way)
Bird Open as 16 bit (BWA from now on)
Moon sky Open as 16 bit (Referred as MS from now on)
To copy one onto the other:
Two methods, first steps are the same:
.Open MS tab (Click on tab)
.
Ctrl-A (select all)
Simplest (Most common):
.
CTRL-C (copy)
.Open BWA (Click on tab)
.
Ctrl-VClick-Drag (Preferred -by me):
.Click on move tool (
V)
.Click on selection Drag onto BWA image tab then BWA image itself
.Release mouse
In both cases a new layer is created in BWA.
Differences:
Naming:
Copy/paste method: Layer1 (need to rename)
Click drag: MS original name
Positioning:
.Because you are using the move tool in click-Drag you can place the image where ever you want.
.You can do the same thing with copy/paste but you need to select the move tool first.
Due to this I almost always use the move tool to copy another image into another one. In this case it does not really matter.To expand this layer so that it covers the BWA layer:
Use Edit-> Free transform (
Ctrl-T) to adjust its position and proportions
Place the MS layer onto one of the WBA corners, click on the opposite MS corner and drag to cover WBA
Now, BlendingPlease not that blending a layer is not about color!!!
Since there is no selection the only method you have is using the layer method
Darken works best
To control the effect:
Opacity option:
.Click on it and dial in the number: either use the mouse wheel (if you have one) or type the number
.Click on the down arrow icon and use the slider
I use the slider first to check the effect then use the mouse wheel for a better incremental adjustment.Fill layer:
.In this instance it will work the same BUT be aware that it is a different beast
Watch this tutorial to understand the differences: http://www.photoshopessentials.com/basics/layers/opacity-vs-fill/ Both options affect the whole layer. To avoid that, use masking (another tutorial:
http://designshack.net/articles/graphics/a-complete-beginners-guide-to-masking-in-photoshop/)
Then to make things a bit more complex you have the blending full options, good luck with that one...
https://www.google.com/search?q=photoshop+blending+options&client=firefox-a&hs=Ivq&rls=org.mozilla:en-US:official&tbm=isch&tbo=u&source=univ&sa=X&ei=P6OLUtzQBKbZ2wWgiYCwDA&ved=0CC4QsAQ&biw=1536&bih=690Tutorial:
https://www.video2brain.com/en/lessons/advanced-blending-options (specifically Blend if)
Now if all you want is to blend the two images as a HDR or panorama like image, un-select the layers you want to blend together and use Edit -> Auto-blend, select option. THIS will not give you any satisfactory result.
I hope this long winded tutorial will help some.