Volcanoes of the world: QTVR

The making of SOL's QTVR-Panoramas

Taking the photos

Some of the photos were taken with a 35mm single lens reflex camera in portrait format in order to achieve maximum possible vertical coverage of the landscape. Sometimes I use a 24mm lens (which requires 12 steps), sometimes a 14mm lens. With the 14mm 360° horizontal coverage is possible with 8 steps (and saves film). 10 or 12 steps gives larger overlap between images. This helps to maintain uniform sky darkness (less effects of lens vignetting) and to suppress reflexes.

My self-made mount makes sure the camera turns around the optical centre of the lens. This avoids unwanted parallax between individual photos. I use a motor winder which reduces the chance of de-aligning the camera when pulling the manual winder (all pictures on this page are links to larger versions.

More recently I have used a professional panorama head made by Manfrotto which allows setting many different angular steps between images. Lately I took panoramas on Stromboli, Lipari and Vulcano using a Nikon digital camera. The lens has an equivalent focal lenght of 28mm which generates panoramas which are less tall but has the advantage that no slide scanning is required.

The circular table

The upper part of the mount turns on the circular table seen on the left. It is equipped with scales which let me turn the camera in regular angular intervals. Three sorts of angular spacings were drawn and glued on the horizontal sliding surface:
30° intervals (12 steps, red markers)
36° intervals (10 steps, blue markers)
45° intervals (8 steps, green markers in the yellow ring)

Turning the camera

The camera is rotated step by step for each photo. It is important to start at step Nr.1 and to make sure that none is omitted. One is easily detracted by reflexes, moving objects or other problems, and I have lost more than one panorama by forgetting one frame or by taking one frame twice and forgetting another one... The worn look of the equipment testifies to some heavy use under, occasionally, rough conditions in the field: For instance, when I did a pano on Stromboli's summit, the Scirocco was so powerful as to knock over camera and heavy tripod. Luckily I just managed to grab the whole assembly fractions of a second before their impact on the ground...

Avoiding reflexes

When using ultra wide angle lenses invariably the sun gets into some of the frames. In order to avoid reflexes («sun flares») I set up the camera in the shade whenever possible. Sometimes I need to go close to some tall object, but this may help to make the panorama even more interesting. Clouds sometimes help to avoid direct sunlight. Cloudy skies are often more interesting than plain blue ones.

If necessary I just block the sun with my hand (image on the left). It is far easier to digitally remove the hand using image processing software than it is to touch up reflexes (image far left). Dark edges around the pictures are not removed, as the rendering software automatically does away with them.

Levelling the camera

A spirit level attached to the finder helps to precisely align the vertical axis of the self-made panorama head. When panoramas are taken along a coast, I sometimes use the central part of the viewfinder to aim at different parts of the horizon instead. This must be done carefully though. Inaccurate levelling leads to strangely undulating horizons.