Another one of my processing technique posts today. For those of you interested in pictures of places, today will probably be one you pass on. You have been warned. This is about my first venture into the realm of HDR panoramas. I know at least one of you who knows exactly how to do this sort of thing and does it on a regular basis. You also will probably skip the rest of the post. However, you have some specialized tools for doing the job and I am playing with Lightroom and Photoshop so here is how it goes.
My initial thought having taken the shots was which order to carry out the processing. HDR first or pano first. I concluded that it had to be pano first. All of the pano exposures were consistent and would stitch properly while I wasn’t convinced that each of the pano frames would be consistent if I had done the HDR blending first. However, this left me with a second concern. Would the pano merge produce images that would align for the HDR merge. I use the pano tools built into Photoshop and, while I select the algorithm it uses, I did not have confidence that it would produce an identical alignment for each set of exposures. However, this was the route I tried.
Stitching the panos was straightforward enough. I created each of them from Lightroom and ended up with five panos with differing exposures. At this point I could have taken them directly to HDR Pro within Photoshop but, since I wanted everything to end up in the Lightroom catalog, I decided to save the files and go to HDR Pro from there.
Here I encountered my first hiccup. As expected, the panos produced were not identical. There were very close but not identical. HDR Pro only works on files that are the same dimensions. I imagine some more specialized HDR applications might be able to handle this but I was stuck with Photoshop. Since the panos were thousands of pixels across and only a few pixels different, I opened them back up in Photoshop and changed the canvas size to be identical in each case. HDR Pro is able to manage alignment of slightly misaligned shots anyway so I wanted worried about the positioning. Also, with such small changes in dimensions, I didn’t fear that I would have distortion.
With this change made, Photoshop went to work and created the HDR file. Amazingly, it worked just fine. I didn’t have any problems with the files being distorted relative to each other and it did a great job of blending them. All that was left was to crop everything in to clear up the empty corners from the pano creation (I didn’t get rid of those in the first instance since I was trying to keep the pano files identical in size and alignment) and then a few tweaks back in Lightroom had the job finished. I was pretty pleased with how it worked and, with the experience of this time, should be able to turn them around quite quickly next time.