Thursday, April 11, 2013

Trying to keep HDRi real

bracketed sunset HDR seriesTaking the sunset tonight, with the polarizing filter still on the lens, I was conscious that the images on the back of the camera was very dark (underexposed) but the colours of the sunset looked rich, like the actual sunset in the +1 EV image from a bracketed set. So I figured I should do a bit more experiments with HDRi in picturenaut using high bits per channel, which this package can only export as .tiff files, but minimal tone mapping. In this case I used just an effective +1.3 EV exposure adjustment of the whole image.. Again I was not able top read the 32 bit version into lightroom, where as picasa could display it? However the 16 bit per channel files loaded easily into lightroom and responded beautifully to some tweaking of the shadows & black tones and slight clarity and luminosity increases. These adjustments did unfortunately highlight the digital noise, which is typical of low light exposures, but this was easily corrected with the lightroom 4’s development/detail sliders.The combine file is no longer a RAW format but it does hold and extended dynamic range that the basic lightroom development controls can adjust, and I feel this approach does it naturally, not in the lurid surreal formats so often blamed on the HDRi technique itself, but are actually related to some preset concepts of the tone mapping options in common HDR packages. So Instead of “finishing” your HDR work in picturenaut, photomatrix or other HDR software, instead try saving the combined image at a higher bits per channel and do the final tonal adjustments in lightroom (or photoshop)
Sequence: {IMGP0673.JPG: TV=0.002857, AV=6.7, Bias=-1.0} {IMGP0674.JPG: TV=0.004000, AV=6.7, Bias=-0.5} {IMGP0675.JPG: TV=0.004000, AV=6.7, Bias=0.0} {IMGP0676.JPG: TV=0.005556, AV=6.7, Bias=0.5} {IMGP0677.JPG: TV=0.008000, AV=5.6, Bias=1.0}
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