Tuesday, June 1, 2010
"Practical HDR" Book Review
Sometime back I wrote a review of Trey Ratcliff's, "A World in HDR." It's a very good book in it's own right, but I found it simply a regurgitation of his very good StuckInCustoms website. So, I thought I'd write up a little something regarding a couple other books I've used to understand the "mechanics" - for lack of a better term - of HDR. One of those books is "Practical HDR" by David Nightingale .
It's comprised of six chapters; Understanding Dynamic Range, Shooting for HDR, Merging Your Bracketed Sequence, Creating Photo-realistic Images, Creating Hyper-real Images and HDR Post-production.
In the first chapter, "Understanding Dynamic Range", Nightingale talks about what HDR is and what the photos we call HDRs really are. The final products that we achieve with the HDR process are really low dynamic range images or LDRs for short. This is because computer screens and printers basically cannot reproduce the range of an HDR image properly, so the HDR image needs to be tone-mapped. When you tone-map, you reduce the range of the image, thus producing an LDR shot. I've never hear it called this before, but he explains it very well. He also gives some great info about how to use the histogram for shooting these types of shots.
The second chapter involves the kind of gear one should use, how to meter a scene, and the bracketing sequence. He states that you can use the minimum 3 brackets from -2 to +2 EVs, but you really don't quite get all of the light much of the time and that it's better to take more brackets at 1 stop EVs instead. Depending on how many brackets you should take for particular scene will depend on what you see in your histogram. Great stuff. I probably need to work on that a little more because I'm kind of lazy when it comes to the histogram. I really only use 5 exposures from -2 to +2 at 1 stop intervals. It seems to work for me most of the time, but once in a while the tone-mapped shot does not look right because I haven't gotten enough light at one end of the scale or the other.
The next chapter, "Merging Your Bracketed Sequence" involves some of the different programs that merge brackets into an HDR image. He mentions Adobe's "Photoshop", "Photomatix" and "FDR Tools". Each one works for different types of shots. Most of us have one version of Photoshop or another as well as Photomatix, but learning about FDR Tools was pretty cool. That piece of software is really good for things that have a lot of lines such a cables from a suspension bridge, the underside of a pier or tree branches that can make the background behind look light on one side of the branch or cable and dark on the other. FDR Tools cleans that up.
The two following chapters involve ways of processing your shots to make them look realistic or for getting more of an artsy look to them. I like both because sometimes I want the picture to look like what I saw when I was there and sometimes I want to add a mood to it.
Lastly, David talks about good ways to remove noise and halos, improving contrast, creating HDRs from a single shot and merging two HDRs. It's interesting info, but I must admit, I haven't tried any of those techniques. But, it's an interesting read.
Spread throughout the book are pictures from the author as well as other well-known HDR artists such as Ben Willmore, Trey Ratcliff and Pete Carr. David Nightingale is no slouch either. I really like the shot of the train tracks on page 127. Very dramatic and a ton of detail.
So as you can see, there's plenty of information in this book to really help one understand what it takes to produce fantastic HDRs. This was the kind of stuff I was hoping would've been in Trey Ratcliff's, "A World in HDR", but this makes a great companion to that book. I highly recommend it!