Ever since I started developing a strong interest in panoramic photography, I also became interested in exploring HDR photography. One day these two finally came together and I decided to capture my first genuine HDR equirectangular panorama. It was not easy but I got there eventually and I’d like to share my thoughts with other panoramic and HDR photography enthusiasts. This post will guide you through the process of capturing a genuine HDR equirectangular panorama and will discuss the issues related to both the equipment as well as workflow. If you are not familiar with panoramic or HDR photography, please read my previous posts: Equirectangular Panorama and HDR from a single RAW
First of all, it has to be said that using a panoramic head to capture a genuine HDR panorama will save you a lot of time and effort. I’ve always been shooting my panoramas using a so-called ‘virtual tripod’ (a technique I’ve described in my previous post on Equirectangular Panorama) and have always been promoting this technique as, comparing to expensive panoramic heads, it is rather inexpensive and you don’t have to carry extra equipment with you. However, in genuine HDR panoramic photography, for every picture you take you will also have to shoot 2 brackets. Therefore, it is extremely difficult to hold your camera steady while taking three pictures at a different shutter speed. Of course there are experienced photographers out there that are capable of doing this, I have also tried and succeeded, but most photographers aren’t as it is not easy.
Once you decide to get a panoramic head, the next question you will ask yourself will be whether you need an expensive or a cheap one. If you have the money, definitely go for the more expensive and professional ones such as Nodal Ninja. If you can’t afford to spend that much for equipment that captures only one kind of images, get a generic brand. As someone who has used both, I can tell you that the cheap generic brands are an excellent option for budget photographers. Expensive panoramic heads, with all the markings and scales, are really easy to set up and use. Most of them are also lighter and are equipped with a rotator and that’s what makes them better than generic panoramic heads. However, they are also more delicate and consist of several different parts that can be lost along the way. If you choose to get a generic brand remember that your tripod’s head has to have 360 degree panoramic rotation. Most cheap heads are not equipped with a rotator, therefore, are unable to rotate. Also check the stability and the way your camera is mounted on the head. You don’t want to risk your DSLR with a fisheye lens mounted on it. All in all, both expensive and inexpensive heads are capable of capturing an equirectangular panorama, once you set them up properly. The only difference is that it may take you longer to set up a generic panoramic head (it took me 30 minutes to set mine).
Another advantage of using a panoramic head in HDR panoramic photography is that shooting handheld brackets indoors (museums, cathedrals, churches etc.) is almost impossible due to challenging light conditions. If you are using a panoramic head and a tripod, you don’t have to worry about light. Unfortunately, tripod photography is forbidden in most public places such as museums and other interesting tourist hotspots.
Once you have the head set up and mounted on your tripod, shoot your panorama as you would normally do, but this time use your camera’s auto-bracketing option to shoot brackets for every picture you take (typically +/- 2EV) and remember to shoot in RAW. This is what makes genuine HDR panoramic photography different from a technique called HDR from a single RAW. Genuine HDR panoramic photography requires you to shoot 3 RAW brackets for every capture and then stack the pictures in HDR software. In fake HDR or HDR from a single RAW you only capture one RAW file and then process it in Photomatix Pro. Once again, I’ve been always promoting the HDR from a single RAW technique, especially in panoramic photography, as it is way easier and does not require so much post-processing. However, shooting your panorama in single RAW files, processing them in Photomatix Pro and then stitching them together generates much more noise. This is important if you want to turn your images into interactive panoramas. Finally, it is also advisable to limit the contact with your camera, so try triggering the shutter with a remote while shooting brackets to avoid any camera shake. One last word of advice. If you are using a panoramic head, you will have plenty of time to take care of such aspects as autofocus and aperture. As one of my friends cleverly noticed, some panoramas in this post have soft, out-of-focus areas. This is mainly caused by using large aperture, as the light conditions inside buildings are very often challenging. However, if your camera is mounted on a tripod, you can use smaller apertures in order to achieve a greater depth of field. Secondly, notice which parts of your image your camera focuses on and shift the AF points if necessary. Like I said, your camera rests on a stable tripod so don’t worry if, by using smaller apertures, you will extend the shutter speed even to several seconds. Once you have all your RAW brackets ready, convert them to 16bit TIFFs with a dedicated RAW converter such as Lightroom 3, Photoshop RAW or Apple Aperture. Your camera will create a -2EV and +2EV brackets but you can also generate additional brackets such as +/-1EV or even -3EV and -4EV. Such heavily underexposed brackets are a great way to pull out details from overexposed areas of your panorama such as windows etc.
Once you have your brackets ready, stack them in Photomatix Pro or Photoshop Merge to HDR plug-in. Whichever software you use, you should have 6 to 8 pictures, depending on your overlap, ready to stitch.
Both, Photomatix Pro and Photoshop are capable of batch processing, which will save you a lot of time. Just drop all the pictures with brackets into a separate folder and the software will do all the hard work, as long as the pictures are named sequentially. You may want to process 3 brackets on your own first in order to save a preset and then apply it to the rest of the pictures.
Now, let’s get down to the stitching process. I have always been using Hugin to stitch my non-HDR panoramas but when I wanted to stitch genuine HDR images I encountered several problems. Occasionally, Hugin was unable to stitch my HDR images stacked in Photomatix Pro. I guess there is a problem with EXIF information but so far I was unable to find out why. However, I found an alternative and now I’m using Autopano Giga, one of the best panorama stitching software available on the market. As a big fan of Hugin (free open-source software) I have to say that I’m simply amazed by Autopano Giga. In a nutshell, it stitches the panorama way faster and the final output is free of any stitching mistakes. The stitching process is really simple. Just follow the step-by-step screenshots below:
Open Autopano Giga and load the images. Since most HDR software usually erases EXIF data, you will have to enter it manually. Just click on the ‘image properties’ icon.
Next, highlight all the pictures and select the right information for the drop down menus. Then click ‘ok’.
After entering all the EXIF information, simply click on ‘detect’ and the software will detect control points and align the images. You can also edit your panorama and adjust numerous settings relating to the layout. When ready, just click on ‘render’ and the software will complete the stitching process.
The final image should look like this:
Obviously, one of the biggest disadvantages of capturing an equirectangular panorama with a panoramic head is that the tripod and the head remain an integral part of the image. However, there is a way to remove the tripod and fix the Nadir of your panorama. What you need is Pano2VR. In a nutshell, Pano2VR is capable of patching your panorama (pulling images out of it and then integrating them back into the final image). The final result will look like this:
Obviously the final HDR image needs further post-processing. Adjust global settings such as contrast, brightness and work on the curve. You can also work with adjustment layers in Photoshop to saturate individual colours, sharpen the image and reduce noise. It is a time-consuming process but it’s definitely worth it.
You can read all about improving the Nadir of your panoramas in my next post: How to capture a perfect Nadir.
If you are interested in exploring HDR photography, make sure you subscribe to Farbspiel’s HDR cookbook, which is currently the most comprehensive HDR photography blog.
Also, there is a very detailed HDR tutorial on Picture Correct.
Thanks for reading and good luck with your photography.
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