53×53 Diptych (Manual Settings)

Posted: August 12, 2010 at 4:24 pm

This is the third diptych prototype. I’ve changed the camera mode from auto white-balance and exposure to manual. The SOM in this case is much stronger, I suppose due to the colour constancy between images. Following are some details:

Details of images arranged by capture location:

Details of images arranged by SOM:

I left the lights on to put more light into the scene, but metering was a little tricky with the bright back-light from the front-door. The range of apertures for this camera (Canon S5IS) is very limited and does not match well with my external light meter. (This is a pretty good reason to go with a digital SLR at some point.) Using incident metering with the semi-sphere diffuser did a reasonable job of getting the right exposure. The square bands of light visible on the ceiling is due to light changes (movement of clouds outside) over the 3 hour exposure.

This size is the largest square possible with this pan/tilt head. Because the tilt range is asymmetrical I offset tilts by a few degrees to start the spiral in the centre of the tilt range. The resulting image is more distorted (notice the parallel lines on the floor) due to the fact that the panning pivot was not horizontal, but tilted forward.

I think this method of capturing images is sufficient for creating some non-prototypes. I’d still like to explore some software to seamlessly stitch images together, rather than using the Gaussian alpha channels. Some brightness/contrast adjustment could normalize away these bands of lighting changes, or perhaps may look more interesting in an outdoor setting. To get a larger (and non-square)  image, a scan-line camera path is needed. In order to make these weather changes more interesting it would make sense that the camera does small vertical slices and moves left to right or right to left. Actually an interesting idea is to use this same method, but do it with a single row of 1 pixel wide images. This would be analogous to slit-scan photography. The interesting part would be organizing the slices according to a SOM.