Aligning Images for HDR

[Robert Schleif]

I have problems with the image alignment that is required for HDR via Stack Images. (I don't often use a tripod, and the images that I obtain hand held using my camera's exposure bracket function need to be aligned.) Obtaining single pixel registration with the Composite transformation is a chore, especially since the refine capability of Composite seems not to work with images of different exposure. Because the images to be aligned are fundamentally very similar, it seems like an automatic or semi-automatic transform could be relatively simple, and appropriate to be part of PWP. Alternatively, is there already a painless way of aligning these images that I haven't thought of?

[MikeG]

Robert,

This is probably not quite the response that you are looking for - but it's what I do.
I use the astonishingly wonderful free CombineZP. It is actually a focus stacking program and the first step is to precisely align the images. I don't (didn't) find the program very intuitive, but, once you know how, it is easy to auto align images and save the aligned images.
The program does NOT handle 16 bit per channel files so any major adjustment should be done first and jpegs submitted to CombineZP for alignment.

Mike.

[den]

To 'image blend' my hand-held bracketed image set exposures [-ev, 0ev, and +ev], I will generally by-pass the need for '1:1 registration' by using the Composite-Blend transform and various 'as needed' Alignments [usually 2-point (shift/rotate/scale)] to:

(1) Merge/substitute the 0ev exposure highlights with the -ev exposure's highlights using an asymmetrical Highlight 3Tone Range mask [see the 3Tone Range mask descriptions detailed here: http://www.ncplus.net/~birchbay/3tone/3tone.htm];

(2) Merge/substitute the modified [resulting step(1) image] 0ev exposure shadows with the +ev exposure's shadows using an asymmetrical Shadow 3Tone Range mask; and then

(3) Proceed: to tone-map/color enhance [manually or with the 2/3-Zone Adjustment transforms]; to local contrast enhance; and to 'creative sharpen'; all to preferences.

If you post an image set [yousendit.com perhaps], I will be glad to provide more detail...