This is the fifth in a series of articles abut passing images between Lightroom, Photoshop and various plugins:
- Are You Wasting Dynamic Range?
- The Lightroom “Edit in…” Problem
- RAW File Processing: Photomatix Pro vs. ACR/Lightroom
- HDR Tools Comparison
- Aligning Images for HDR
One step in the process of creating an HDR image is the alignment of the bracketed originals. If you’re working with a single RAW image (possibly extracting extended highlight or shadow detail using Klaus Hermann’s Five TIFFs method) this isn’t a problem as you’ll only have one image or the pixels in your extra images will be perfectly registered. If you’re using multiple exposures and a tripod, you won’t have perfectly aligned pixels, but they’ll be close. However, if you’re shooting bracketed exposures handheld, aligning your source images presents an interesting software challenge.
For this article is used two bracketed images (to keep things simple) that were shot handheld. The images below show how well four different applications were able to align the images.
- Photomatrix Pro (upper left) doesn’t appear to have a particularly good alignment algorithm, although we might be seeing some other artifact of that apps’ processing. It’s hard to tell
- LR/Enfuse (upper right) does such a bad job of aligning the two images (using default settings) the offset is almost the entire width of these 200% scale images.
- NIK’s HDR Efex Pro (lower right) looks a little better than Photomatix Pro but still not as good as Photoshop (next).
- From Lightroom, Merge to HDR Pro in Photoshop CS5 (lower left) appears to do the best job of aligning the images.
But while Photoshop may be the best tool for aligning images, we also know that it’s one of the weakest HDR applications for other reasons. How then can we take advantage of Photoshop’s alignment feature while using one of the other superior HDR apps?
For my more critical HDR images, my workflow now includes the following steps:
- Select all the images (including any extended-EV TIFFs) in Lightroom.
- In the Lightroom menu: Photo > Edit in > Open as Layers in Photoshop…
- In Photoshop, select all layers.
- From the Photoshop menu: Edit > Auto-Align Layers > Auto.
- Crop the image (all layers) to eliminate areas that aren’t present in all layers.
- Save each layer as a 16-bit ProPhoto RGB TIFF.
- Use these derivative TIFFs as the input to my HDR application of choice.
To see the results of this portion of the workflow, consider the following images, each produced in this way.
- Photomatix Pro (upper left) has been improved somewhat.
- LR/Enfuse (upper right) has gone from worst to best.
- HDR Efex Pro (lower left) has also improved a bit.
This portion of my workflow is fairly time consuming and I don’t use it all the time. But when I have an HDR image that’s critical, particularly when it was shot handheld or if I’m trying to achieve a particularly realistic (non-HDR-ish) look, this is what I do. And increasingly I’m using LR/Enfuse as my HDR tool of choice.
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