Shooting High Dynamic Range
- 2. What is High-Dynamic Range Photography? Post-processing technique where multiple exposures are combined to create a single image with higher dynamic range. They are 32-bit images (96-bits per colour pixel) with an infinite set of values each pixel can take (floating point). Standard RAW images are 12-bit and JPEG are 8-bit. In order to reproduce the dynamic range on low dynamic range displays or prints, the ranges are compressed using by tone mapping.
- 3. A ‘bit’ of conversion 12-bit RAW 12-bit RAW 12-bit RAW 8-bit 32-bit HDR 8-bit HDR8-bit 8-bit RAW Conversion (optional) Exposure Blending Tone Mapping (Dynamic Range Compression)
- 6. HDR Image
- 7. Not entirely new Gustave Le Gray, (1820–1884) Source: http://en.wikipedia.org/wiki/Gustave_Le_Gray
- 8. Why HDR? “well… you really had to be there…” Film/CCDs are not eyes we are under a patchwork illusion all the time (but ignorance is bliss) Realistic Surreal Increases your photo-taking possibilities e.g. eliminate need for fill-in flash for indoor/outdoor hybrid shots, direct sunlight, …
- 9. What you need A (digital) camera Preferably capable of auto exposure bracketing Ideally a tripod HDR software Some free, some commercial Lots of other optional tools Photoshop …
- 11. Taking the photos Preferably use a tripod Use Automatic Exposure Bracketing (AEB) where possible Shoot in either JPEG or RAW. HDR software can handle several RAW formats. Source: http://www.usa.canon.com/dlc/controller?act=GetArticleAct&articleID=1646
- 12. Preparing the photos Be aware of any moving subjects can remove before to avoid ghosting or do in a single step after the HDR image is created HDR software may be able to avoid ghosting but there will always be cases where it fails
- 13. Tone mapping Depends what effect you want but if realism is what you’re after then you have to be very careful. Potential unwanted effects include halos, tone reversals, noise and sometimes just too much color!
- 14. Tone mapping Source: http://beforethecoffee.wordpress.com/photomatix-tutorial/
- 15. Surreal HDR Photo by welshbaloney http://www.flickr.com/photos/welshbaloney/ Photo by aicizz http://www.flickr.com/photos/aicizz/
- 16. True Tone HDR (TTHDR) Photos by ojaipatrick http://www.flickr.com/photos/ojaipatrick/
- 17. Blown-out Skies
- 20. Nothing right
- 22. Direct Sunlight
- 23. Direct Sunlight
- 24. Direct Sunlight
- 25. Direct Sunlight
- 26. Moving Targets
- 27. Moving Targets
- 28. Moving Targets
- 29. Moving Targets
- 30. Where are the colours?
- 31. Where are the colours?
- 32. A dull day?
- 33. A dull day?
- 34. Exposures and how many? Spot metering on the highlights and shadows, note the exposure times. Multiply exposure time for highlights by four successively (stop spacing of 2 EV) until you pass the exposure time for the shadows. Three exposures with 2 EV is typically good but you may have to go to full manual depending on your camera model.
- 35. Remember your settings Settings should remain constant for all the images in a series Focus Aperture (set small) ISO (set as low as possible, particular if using tripod) Auto white balancing (beware but impact minimised) Custom white balance or shoot in RAW
- 36. RAW ‘HDR’ Not strictly HDR but using a good RAW converter you can create fake exposures which sometimes squeeze more data out than you would otherwise with a single image. Due to good noise reduction Dynamic range is essentially the same though as you’re simply splitting the dynamic range of a single RAW image (12-bits per colour) into slices and then recombining.
- 37. HDR Panorama Panorama first, then HDR same effect across whole image
- 38. Post-post-processing Re introduce originals to make more realistic and get rid of any ghosting. De-noising further. HDR software can be very powerful but there may be times that you’d prefer touching up further with what you’re familiar with.
- 39. HDR in conclusion Diverse: ultra-realistic to shockingly surreal Personal taste but think about what your aims are Don’t use for the sake of it If the scene lends itself to higher dynamic range, otherwise many other post-processing techniques that might be more suitable Go play, either casually or more seriously Doesn’t take long to get results and there is an element of exploration and discovery in the tone mapping process in particular