High Dynamic Range Cave Photography Mike Bedford
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Transcript of High Dynamic Range Cave Photography Mike Bedford
High Dynamic RangeCave Photography
Mike Bedford
British Cave Research AssociationCave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
A miracle of optical engineering?
Perhaps …
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
… but this is a better one.
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Comparing Dynamic Range
Dynamic Range
Human Eye > 1,000,000 : 1
Human Eye (single scene) 10,000 : 1
High-contrast Daylight Scene 10,000 : 1
Point & Shoot Digital Camera 256 : 1
Good Quality Digital SLR Camera 2,000 : 1
JPEG Image File 256 : 1
Conclusion: Ordinary digital photography can’t properly capture some scenes or even compete with the human eye.
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Demonstrating the Problem
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
A Solution
+2EV
-2EV
0EV
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
The Process -Practically• Mount camera on Tripod (although software
can correct for alignment errors)• Take multiple exposures of same scene– Typically +2EV, 0EV & -2EV– or +2EV, +1EV, 0EV, -1EV & -2EV– although more stops overexposure might be
needed for caving use
• Use aperture priority• Process in software to create HDR image
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Tone Mapping• HDR software generates an HDR image• Can be stored using file formats designed specially
for HDR images • While Jpeg has dynamic range of 256 : 1
.dds, .exr, .hdr etc. offer 64,000 : 1 or more• But an LCD monitor provides 1,000 : 1 max• Prints offer an even lower dynamic range• Tone mapping is required to view on an ordinary
monitor or print• Provides scope for creativity
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Tone Mapping Example
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Tone Mapping Example
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Tone Mapping Example
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Tone Mapping Example
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
A Sunset
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
A Sunset
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
A Sunset
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Architectural Interiors
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Architectural Interiors
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Architectural Interiors
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
The Ultimate – Cave Entrances
• One of the highest dynamic range scenes we’re likely to encounter
• Inside looking out and outside looking in both present challenges
• Probably need to overexpose bymore than 2EV
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Browgill Cave
from the onsidelooking out
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Browgill Cave
from the insidelooking out
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Browgill Cave
from the insidelooking out
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Browgill Cave - from the outside looking in
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Browgill Cave
from the outsidelooking out
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Roger Kirk Cave
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Las Cuevas deSanto Tomás, Cuba
British Cave Research Association - Cave Technology Symposium 20119th April 2011, Ashbourne, Derbyshire
Thank you for ListeningAny Questions?