Unfortunately, it doesn't work well at all with the sample raw files provided by Guillermo Lujik. There are nasty highlight artifacts. Granted, the difference is 4 stops, not 3. Adjusting the sliders so that one gets rid of the highlight artifacts also seems to get rid of the reduced noise.
Jonathan's method seems to be an improvement over other blending techniques I've come across, but it still relies upon post-blending skills in Photoshop.
I struggle with Photoshop techniques. I know I should spend hours and hours pouring over Photoshop manuals, but for some reason I'm reluctant to do so. Is it a fear of becoming a nerd, or is it just I'm a lazy student who wants the glamour but not the hard yakka? I don't know. A bit of both probably.
I mentioned before, in blending images there's often a halo effect around borders between high contrast transitions. I don't have the skills to get rid of these, at least without painstaking hours of work.
I'm thinking that maybe GLuijk's method offers a quick solution to this.
If you've got the patience, I'll go through a processing procedure I used to blend a couple of images that varied by 4 stops, using Jonathan's method. The final result is not perfect, and not to my complete satisfaction.
The following is a scene of a 5 star hotel 'ensuite' in the foothills of Nepal. (5 stars is relative, you understand ). The cost for one night in this luxurious accommodation was just US$4. That's less than 1$ per star . I wanted to capture the scene out of the bathroom window, as well as the bathroom itself.
One shot would simply not do. So I brought my tripod into the bathroom and took a series of 3 bracketed shots.
Here's my attempt at blending 2 of those 3 shots, using Jonathan's method.
(1) The initial blend. Jonathan's recommended settings for "This Layer" should be varied according to the circumstances. It might be right for exposures differences of 3 stops, but my exposures differed by 4 stops, consequently my split layer values were not 35/220, as Jonathan suggested. but 28/43, based upon eyeballing, not mathematical calculation.
Having flattened the image, I then proceeded to use the limited but familiar techniques I normally use to get the image into shape.
First, a curves application to raise the shadows.
Then a shadows/highlight adjustment.
Then a levels adjustment.
After the levels adjustment (ctrl click on RGB channels, reverse selection, layers levels, 80% opacity), the levels histogram looks like this.
So here is the rather flat image lacking in umph!
The problem is; how do I get from this rather flat image to the final vision without introducing artifacts around the edges of the window frames?