A Question About Panoramas
I received an interesting question from a reader last week concerning my blog and my overly long Youtube video showing how I record panorama images. I thought I’d share his question and my response.
Hi Les, many thanks for this nice instructional video on how to shoot multi row panoramas! It was to the point and very nicely delivered! I’d like just to ask if it possible for you to share some tips on the use of polarizing filters when creating panoramas, since the different orientation of the camera throughout the series of shots would invariably introduce some inconsistencies on the final image, which would be especially visible on the sky. Many thanks again and I hope this request may be considered for one of your next tutorials on the subject! Best regards Marco
Excellent question, Marco, and one that I probably should have addressed in the video. The answer, like so many in photography, is that it depends. It depends on the experience and point of view of the photographer and it depends on the circumstances of the image you are recording. Here’s the explanation:
Some Background
For those new to photography or to using polarizers, I’ll mention three important facts. First, polarizers are used to improve contrast in the sky so that clouds will pop and landscape colors will intensify a tad. Second, polarizers have maximum impact when the camera is facing 90 degrees from the sun. Third, using a polarizer will restrict the amount of light coming through it by 1 to 1.5 stops.
By and large I really don’t think too much about my polarizer. Point of fact is that when I am recoding landscapes I have my polarizer on 80% of the time. If I am taking a single image I just adjust the polarizer and shoot; no problem there.
But, as Marco points out, as you pan from left to right, you are changing the camera’s orientation so that the polarizer will have differential effects. At the extreme left you might be 20 degrees from the sun and as you pan to the right you are increasing the angle and thereby getting more polarization. That usually shows up as darker blue patches in the sky that can be maddeningly frustrating to deal with in post-processing.
My Fixes
I usually employ one of two solutions to the problem. First, I ignore it. Many times you will be shooting a pano with the sun behind you, lighting up a mountain range for example. The lead image is a good example of this. Even though the image encompasses a lot of territory in Iceland, the sun was behind me (i.e. 180 degrees) and my polarizer basically had zero effect, other than giving me less light, which in this case I wanted to happen so that I could get a nice water blur due to the choppy conditions.
But what about situations where the sun is just to the left or right of the pano? In those cases as I pan the impact of the polarizer would be significant. My solution is to remove the polarizer and bracket my shots, then merge the images so that I can still have skies with the clouds popping. I’m not talking heavy-handed HDR here, which I am personally not into. I am just talking about balancing the sky with foreground to achieve a natural look.
The “Naturalist” Objection
One final item before leaving the topic. I often get the perennial dumb-ass comment from some photographers that merging images is not “natural.” Oh, really? Are you telling me that your eyes only saw the foreground in deep shadow with no detail? Or perhaps the sky was so bright you couldn’t see one cloud clearly? If that’s so, then you’d better run, not walk, to your eye doctor. My point here is that the human eye is still far more sensitive and has a greater dynamic range than even the best sensors we have. When we look at a scene we see details in the shadows and in the sky.
A camera, however, is a dumb machine. It does its best to compensate for wide variations in light, but in most cases will render that mountain valley as a silhouette and the sky in beautiful detail. Or, if you expose for the valley, it will completely blow out the sky.
So, which is “natural” I ask you? By merging images I am simply making up for the camera’s deficiencies, rendering the scene as my eyes saw it. Of course, there are times when I plan to sell an image as fine art rather than for editorial work, and in those cases I might add something in post-processing to create drama.
I hope this addresses your question, Marco. If not, please don’t hesitate to check in again. And, please do share with us some of your work. I like to highlight my readers' work from time to time. Contact me here and I’ll get back to you with instructions on how to send me images.