How can I merge these images ?

[sid]

I took these two pictures with different exposures with the intention of combining them in photoshop (or gimp) to get a better exposed image. Now, the problem is, I dont really know how to achieve this. I've given it a shot, but failed miserably. Can anyone help me ? Appreciate the guidance

[GoneFission]

Here's a quick and dirty merge in the GIMP:
http://www.gonefission.us/Uploads/sid_merge.jpg

(I hope you don't mind me editing your pics... I will certainly take this down if you do)

What I did:
1. Copy the "sky" pic, and paste as a new layer over the "ground" pic
2. Add layer mask
3. Fill layer mask with about 50% gray, so I could see both layers
4. Move "sky" layer until the two were aligned (or at least mostly so... the upper left and upper right are a little out of alignment)
5. Fill layer mask with white (transparent)
6. Use paintbrush to rough-in the boundary between sky and ground with black (opaque)
7. Use airbrush to soften the transition

As you can see, there is a bit of a "halo" around the mountain... this is partly due to my haste, and partly due to the image size - the originals would provide a better boundary.

Luminous Landscape has a pretty good tutorial (http://www.luminous-landscape.com/tutorials/blended_exposures.shtml) on this.

[GoneFission]

Here's the result of a different method:
http://www.gonefission.us/Uploads/sid_merge1.jpg

Sometimes I forget to take two exposures, or the two will be impossible to align (I really need a tripod...), so I'll just use the underexposed pic, which is what I did here.

1. Make duplicate layer of background
2. Adjust levels until foreground is as light as desired
3. Add layer mask based on inverse grayscale copy of layer
4. Use the threshold tool to reduce to b&w. This requires some experimentation to figure out the right setting to get the desired boundary.
5. Clean up mask with paintbrush

This method yielded a much cleaner merge, since the two layers lined up exactly. I've found that the threshold trick doesn't work on all images, but it worked nicely here, where there is a rather distinct boundary between the sky and ground. Also, this method won't work very well when the underexposed part is extremely underexposed.

Hope this helps!

[tim]

Do you have CS2? That makes it really easy with its HDR feature.

[sid]

Thanks for the tips guys ! I dont mind you editing the images. I'm learning a lot through this process :)
I just have PS Elements, no CS2. Too expensive for me. I usually use gimp but right now I'm travelling and dont have access to my linux machine.

[tim]

I can have a bit of a play with them in CS2 if you like. If you want to email the source files to me I can try in a few hours when I get home. No guarantees, sometimes it's fussy. My email address is on the front page of my website (http://mrwild.co.nz) (I don't write it all over the place to prevent spam).

[kram]

[QUOTE=GoneFission]Here's a quick and dirty merge in the GIMP:

Sorry, what is GIMP?

[tim]

GIMP is a free image editor, written for unix/linux, but there's a version for windows too. Look at http://gimp.org/