I am stitching panoramas. How should I integrate Photomatix in my workflow?
As you know, getting a seamless panorama is best achieved by maintaining a constant exposure when shooting the panorama’s views. The problem is that the right exposure is different for each view. Photomatix Pro can help solve this dilemma.
First of all, you will need to shoot each one of the panorama’s angles of view at different exposures (for instance three exposures at 0, -2, +2 EV). Those exposures should remain the same for all of the angles of view of your panorama. This is easy if your camera has an auto-bracketing function — set the exposure to manual mode, then select auto-bracketing after having set the appropriate aperture (the bracketing function will change the shutter speed automatically).
If your panorama software supports 32-bit HDR stitching, then you can use Photomatix to create the 32-bit HDR images in input of stitching, and later on to tone map the 32-bit HDR panorama once it has been stitched. In this case, integrating Photomatix in your workflow is not different than with standard images and you don’t need to read the rest of this section. Please refer instead to the section on large files.
If your panorama software does not support 32-bit HDR stitching, there are two possibilities for integrating Photomatix in your panorama workflow:
1. Stitch-then-HDR: create multi exposed panoramas and process them in Photomatix
2. HDR-then-Stitch: process your bracketed images in Photomatix and stitch the tone mapped or combined images
We are using the first workflow, i.e. Stitch-then-HDR. This means producing one panorama for each exposure level and then merging those panoramas in Photomatix.
However, the Stitch-then-HDR workflow assumes that the differently exposed panoramas are stitched the same way, i.e. using the same control points for each panorama. This can only work if your stitching software makes it possible to replicate the stitching parameters used for one panorama to another panorama, so that it can stitch your differently exposed panoramas exactly the same way. This is possible, for instance, with software based on Panotools (see below) and with Autodesk Stitcher (see below). If this is not the case (e.g. with Panoweaver), you will have to use Photomatix prior to stitching, i.e. merging your bracketed shots for each one of the angle of views and then stitch together the resulting images.
The second type of workflow, HDR-then-Stitch, avoids multiple stitches per pano, which is an advantage if your pano is composed of a limited number of views. The drawback, however, is that this approach may not work well with the dynamic range increase techniques that take the most advantage of local contrast, especially the Tone Mapping tool. Because local contrast is specific to a given view, those techniques produce images with different tone levels, making them more difficult to stitch.
It does not necessarily mean, though, that you won’t be able to stitch images obtained via HDR Tone Mapping. We have heard for instance that Autodesk Stitcher does a good job at stitching tone mapped images produced by Photomatix Pro. If you have similar experiences with other stitching applications, please let us know.
In any case, we recommend using Photomatix in batch mode for processing panoramas. The Batch Processing of Photomatix Pro has been designed with the needs of panographers in mind.