1. High Dynamic Range Cave Photography Mike Bedford British Cave Research Association Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire

2. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire A miracle of optical engineering? Perhaps …

3. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire … but this is a better one.

4. British Cave Research Association - Cave Technology Symposium 2011 9 th 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 Scene10,000 : 1 Point & Shoot Digital Camera256 : 1 Good Quality Digital SLR Camera2,000 : 1 JPEG Image File256 : 1 Conclusion: Ordinary digital photography can’t properly capture some scenes or even compete with the human eye.

5. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Demonstrating the Problem

6. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire A Solution +2EV -2EV 0EV

7. British Cave Research Association - Cave Technology Symposium 2011 9 th 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

8. British Cave Research Association - Cave Technology Symposium 2011 9 th 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

9. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Tone Mapping Example

10. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Tone Mapping Example

11. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Tone Mapping Example

12. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Tone Mapping Example

13. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire A Sunset

14. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire A Sunset

15. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire A Sunset

16. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Architectural Interiors

17. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Architectural Interiors

18. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Architectural Interiors

19. British Cave Research Association - Cave Technology Symposium 2011 9 th 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 by more than 2EV

20. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Browgill Cave from the onside looking out

21. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Browgill Cave from the inside looking out

22. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Browgill Cave from the inside looking out

23. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Browgill Cave - from the outside looking in

24. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Browgill Cave from the outside looking out

25. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Roger Kirk Cave

26. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Las Cuevas de Santo Tomás, Cuba

27. British Cave Research Association - Cave Technology Symposium 2011 9 th April 2011, Ashbourne, Derbyshire Thank you for Listening Any Questions?