I have recently spent some time taking panoramic pictures of the Halley Interior – you may have seen some of those in the Antarctica366 Project gallery. There is a reason for all this – find out more after the break!
Halley Station Virtual Tour
Ladies and Gentlemen, I would like to invite you for a virtual visit to the British Antarctic Survey’s most remote, most isolated and the most Southerly outpost – Halley VI Research Station!
How was this made?
Over the course of last ten days or so, I have made thirty 360° by 180° panoramic images inside the Halley Station modules, each requiring a minimum of nine individual images and about 30 minutes to an hour of processing and stitching time.
I placed the camera on a tripod in the middle of each of the thirty locations on station. I used a simple panoramic head for my tripod (a Nodal Ninja) which allowed me to “push” the camera back, so that it rotates around the optical centre of the lens. This removes the parallax error and therefore making the stitching much easier. I’ve spent some 15-20 minutes calibrating the position of the camera to make it as close to that optical centre as I was able to, and then just took note of the various distances on the pano-head’s rails.
I then made sure the head on the tripod is as level as is possible. The Nodal Ninja I have doesn’t have any mechanisms for precise levelling, so I used the ball head of my tripod to do just that, with the Nodal Ninja mounted on top.
I used a Nikon D750 with a Nikkor 10.5mm f/2.8 AF DX Fisheye lens. Huh? A crop lens on a full-frame body? There’s actually a reason for that:
- The 10.5mm DX is the only Fisheye lens I have, back from the days I was shooting on crop sensor Nikon D200. I also use it for underwater photography with my Nikon D60. Fisheye lenses make it the easiest to shoot 360° panoramas with.
- Even though only the middle part of the sensor of my D750 is used, it’s still a much better quality sensor than the one in the D60 I have with me as my backup camera, resulting in much cleaner and nicer images.
- Each panorama is 60 megapixel in size. Yes, they are smaller than if shot at full-frame size, but still plenty big for what I want to use them for!
I’ve had the camera set to fully manual settings for everything. I’d manually set the focus and turn off AF, manual white balance (typically set to Tungsten), and manual exposure settings (ISO, shutter speed, aperture).
I typically took a minimum of nine, but most often ten or eleven individual shots to shoot each room. Using the Fisheye lens, I was able to take 6 images around the horizon (each at 60° angle from the previous one), which gave me a good overlap, again assisting the stitching software later. I then took a single picture of the ceiling (the camera pointing straight up), and two images of the floor (the camera pointing straight down). The pictures of the floor were rotated 90° against each other (so, for example I would take one in the North-South orientation and then rotate the camera to East-West orientation).
Finally, to remove the tripod from the image, I took a third, handheld image with the tripod moved out of the way and with the camera as close to the position it was in when still mounted as I was able to. For this I usually took three or so images in quick succession, to ensure there’s as little motion blur as possible (some of the rooms have enough light for human eyes, but make it quite challenging for handheld photography).
I have imported each of the images into Lightroom and did my initial processing there. Most of the processing consists of fine tuning the colour temperature (white balance), and enhancing the images (setting shadows, clarity, vibrance) to taste. I also enabled lens correction with the exception of Distortion, which I’ve left uncorrected for the benefit of the stitching program.
I’ve added all required keywords and metadata like location, etc. I then grouped images making up a single room into a stack (for easier management later) and finally exported them for stitching.
My program of choice for stitching panoramas is AutoPano Giga. For most rooms this wasn’t really a challenge, as there is enough detail in each of the rooms that the APG had no trouble finding several numbers of common points between adjacent images. For those, it was just a case of identifying the bits I wanted masked out of the panorama (mainly the tripod) using the Remove / Keep markers in the Mask Edition tool. I also enabled “Optimise the viewpoint” option for the handheld image of Nadir (the floor) using the Control Points Editor tool. The final step was to find vertical lines in the image and mark them using the Verticals Tool to ensure the image is level.
Some of the areas, however, turned out to be a bit more tricky. I’ve struggled most with some corridors, especially when there are no features on the walls (modules B2, E2 and H2 come to mind). This seems to be most problematic when the corridors are completely symmetrical. In the case of those three modules, I had to actually go and reshoot them from a different point. The stitching process, once the program was able to link individual images correctly, was pretty much the same as above.
All stitching done, I’ve built the panoramas in AutoPano Giga as tif files for importing back into Lightroom (so that I can add them to my Antarctica366 Project gallery or just use them statically), as well as into the native .kro files, to use them for the virtual tour.
The final step was to import the .kro images of all the rooms into the PanoTour software and build the virtual tour there. I’ve first grouped all rooms / areas from to the same module into a group – I ended up with nine groups, one for each of the eight modules, and one for the bridge. After that it was a case of going via each of those rooms, setting up the Nadir patch and linking them with each other by marking doors and areas and choosing which of the rooms these lead into. Finally, I’ve put some finishing touches (like the logos in the top corners and the splash screen image) and clicked Build. It took some 30 minutes or so, but after that I was able to sync the resulting set of files up to my server – and now I can share them with you!