Description:
HDRi skydome panorama in .exr and .hdr format for use as a spherical environment in 3d scenes. 1554 refers to the time of day it was taken.
Resolution:
Approx 7000px wide, good enough in some cases to be used as the directly visible sky. When you want more control, or the sky is visibly low res, you can use the supplied 12 megapixel jpg backplates.
Dynamic Range:
All photos used to make the HDRi are taken at the following exposures:
1/8000, 1/2000, 1/500, 1/125, 1/30, 1/8, 1/2
which is equivalent to a dynamic range of 12 EVs (Exposure Values). A Canon 5D mk2 was used and was set to shoot 7 exposures 2 EVs apart. Exposures longer than 1 second give problems with moving clouds.
The .exr files are about 70mb each.
High dynamic range within a HDR image is important if you are looking to get realistic shadows from the sun.
Backplates:
Comes with 33 straight shots of the sky taken at the same time as the HDRi and with the same color temperature so it matches your render. Each jpg is 4368×2912 px and about 2.5mb.
In all HDRs the sun (or brightest part) is oriented south>north for easy control of shadow direction.
The rendered preview above is shown using my most recent HDRi workflow which you can read more about here: http://www.peterguthrie.net/blog/2012/02/hdri-lighting-workflow/ . It is rendered using a gamma of 0.8 for the HDRi.