HOME RUN PICTURES - INITIAL TEST OF RED CAMERA WITH SIGMA LENS
For an initial test of the RED camera using the Sigma 4.5mm fisheye, we shot several scenes near our studio at midday. The sky was bright with clouds rolling over the sun occasionally. You can view two sample scenes here... one in full sunlight, the second, a shadowed scene with the sun behind a cloud. Our primary goal is to test the camera/lens combination in various lighting conditions and see how the sensor performs in the hi-light and shadow areas. All shots were simply handheld so not the most usable for fulldome, but sufficient for our tests. An 8Gb CF card was filled with about 6-7 minutes of video at the RED's maximum resolution setting. The RED's raw format files were then processed with The REDcine raw software application to adjust color and contrast... to end up with a sequence of frames suitable for fulldome projection. The sensor captured approximately a 2300x2300 pixel usable area image circle.
A full-rez tga file of a single sample frame can be downloaded by clicking on the above images. Small Quicktime movies of each of the two sequences are available by clicking on the links below... they are quite compressed for quick download, larger movies are available...
The initial stacks of video frames look good and what noise there is, is only visible in the darker shadow areas after raising the saturation levels considerably during raw processing, which seems to be a necessity since saturation was, by default, too low for good fulldome projection. The 7-stop RED raw capture format offers a good latitude of contrast range to work with during processing of frames specifically for fulldome use. We did not vary the f/stop setting on the Sigma, so cannot yet comment on any variation of sharpness at different settings.
We will continue to test further, but this camera/lens combination looks like it has good potential for fulldome video capture. Best performance seems to be in bright sunlight. The scene shot in shade was more difficult to process for a good fulldome usable image, but that may just be a matter of garnering more experience with the RED raw processing toolset (which is a beta version also). The 2300x2300 circle acquired, while not at the maximum resolution some fulldome shows are rendered at, should be of sufficient resolution to please an audience because of the increased visual detail a "real" image naturally has.
More to come...
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