An alternative technique
Hi Paul
I have been really excited about the artistic possibilities opened up by blended exposures, and long exposures.
However, it wasn't until I got a technique described in a forum at dpreview to actually work for me, that I feel that the true utility of digital blending has become a useful, as opposed to a truly frustrating, option.
The technique involves creating a luminosity mask, and the beauty of the technique is that the computer does the hard work. No brushwork is required, although you can certainly go back and add your own fine handwork to the process.
I was frustrated for months, trying to read recipes for this process and get them to actually work in CS1! The recipe involves hitting four keystrokes simultaneously at one point, with one of them being the tilde key. I have a sneaking suspicion that the tilde symbol (~) got lost in previous translations of poster's documents into HTML.
I can tell you that the first time I hit those four keystrokes, and was rewarded with a screen filled with "marching ants", I literally let out a war whoop, and danced around the room!
Here is the technique. It works best if you combine exposures that are each not too too different from each other. I have a favorite landscape that is a blend of 4 or 5 exposures - which translates to something like 8 or 10separate exposure settings across the range, with every other one being blended.
Here is the technique - I hope it can help you.
How to do Automated Luminosity Masking
1a) Open up the two images to blend. If you have a bunch of the same scene using a tripod, and want a blend using the whole dynamic range, it is better to make multiple blends, each of exposures *not too far apart from each other*
1b)Using move tool, SHIFT-left click to drag darker image onto lighter image
1c) Minimize the 1st dark image
2) Important - - verify alignment by Layer window ( where you see the layers, layer masks, etc) options list - difference mode. Zoom in is best, so that you can move image by pixil at a time using arrow keys. -> be sure to set Layers Mode back to normal when done!
3) ALT-left click on eye icon on background ( lower) layer. The picture should become lighter.
4) CONTROL-SHIFT-ALT- ~ ( tilde key) creates luminosity mask. Hit all four of these keys simultaneously. You should now see “marching ants” delineating the highlights.
5) ALT-click missing eye icon (hit the space where it used to be) on the upper layer. The picture should now turn very dark. i
6) Go to the main “LAYERS” menu at top of screen, , select “Add layer mask” and “reveal selection”. Boom!!
to improve:
7) ALT-click on layer mask icon ( on original layer, to the right. This will be the upper layer of the two, and all the way tot he right)
8) Gaussian blur of about 3 pixils - apply. This should sharpen the pic. To check, zoom in, click ( not alt-click) on the layer thumbnail, to the left of the layer mask thumbnail.
To improve BIGTIME:
9) again, click ( not alt-click), on the layer mask thumbnail to activate it. Open up the LEVELS box in the Adjustments section, and adjust blend using “Levels” adjustments. Basically slide the middle slider to the right to “blend” the relative contributions of the two pictures. That’s all, folks!
10) Flatten image
11) Continue processing