Thursday, May 26, 2011

HDR (32 bpc) Photography- My very first HDRI.


For CG visual effects of the Action/ Sci-Fi Short Movie I am producing nowadays needs some HDR Images. So, for the first time, I am in a need of shooting some Photographs and make some HDRIs out of 'em. Here is a successful test I've done using some images shot at one of a locations I used for filming the short movie.

It was a viable experiment for breaking the ice on HDR Photographing...

HDR (High Dynamic Range) Photography - 32bpc Images.

Basically (At least for years in Digital video/Photo-graphy) we used 8bpc (8 Bits Per Channel) images. Each channel of RGB (Red, Green, Blue) represented by a digital code length of 8-bits (255 possible colour values). And together all three RGB channels we could specify 16777216 (255 X 255 X 255) colours (SVGA or True Colours). In true colours computer uses 24 'bits per pixel' (bpp) to store an image (8bits per each indivdual RGB channels). 


HDR uses 32 bits per each individual RGB channel, allowing us to use very large dynamic amount of colours with greater contrast. 


Basically What I did was; I shot 5 different Photographs using 5 different exposure values. 
Ex -2, ISO 200. White Balance -Daylight Mood.
Ex -1, ISO 200. White Balance -Daylight Mood.
Ex 0, ISO 200. White Balance -Daylight Mood.
Ex 1, ISO 200. White Balance -Daylight Mood.
Ex 2, ISO 200. White Balance -Daylight Mood.
Then I stack them together. You can use software, such as; Photoshop or photomatix pro for this purpose. And refined image using available adjustment tools.

Here is the final HDR Image. (Click To Enlarge). 
HDRI - Click To Enlarge
Camera Used - Canon PowerShot A480.

At least you need 3 photos shot using 3 different Ex values to produce a HDRI but more photos you use the outcome will be stunning.

I thought of providing more information upon making HDRI. But, I am afraid, these days I am running around the clock to finish the post production of my short movie. 

I will Try to back with more details...

See you Later.

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