The HDRI Handbook: High Dynamic Range Imaging for Photographers and CG Artists
By Christian Bloch
Says Dan Dill
about this book:
I have been learning about HDRI primarily from Uwe Steinmueller's generously helpful articles on his site outbackphoto.com
, and from the Photomatix email list. Seeing that Steinmueller is a contributor to The HDRI Handbook, I expected it to be more of the same.
In the event, it has been an epiphany. I had not appreciated that HDRI is a doorway into truly archival imaging, for today's imaging technology *and* for imaging tools and output devices not yet invented. I had completely missed the point made on page 132 of The HDRI Handbook:
Most photographers will tell you that the next step
[after having merged bracketed exposures into an HDR image] is tone mapping because an HDR image doesn't fit the limited range of our ..." output devices. "This is missing the whole point."
*Don't throw it all away yet!* There is nothing special about an HDR image. It's all just pixels waiting to be messed with, but better pixels that are much more forgiving when we apply extreme edits. Imagine the HDR image as raw clay that we can form into whatever we want. Why would you burn that raw clay into a hard block now just so you can destructively chisel the final form out of it?. Wouldn't it make much more sense to massage the clay into a good model first?
[ Apply non-destructive edits to the HDR image itself!] And then put it in the oven the fix that form
[tone map into an KDR image], and sand and polish
[fine-tune with LDR editing tools] afterwards?
To speak in more photographic terms: Here we have an image that exceeds the tonal range and qualities of a RAW image. Wouldn't it be great to keep it like that for as long as possible? Well, you can! That's what true HDR workflow is all about.
Christian Bloch then describes a 32-bit Photoshop (CS3 Extended) workflow to do just this.
An HDR > LDR workflow can be broken down into three parts. Bloch describes and compares the tools available for each part, and examples of these are provided on the DVD that comes with the book.
One perspective is to have "the final image appear as natural as possible, ... an image that looks like it was shot with an ordinary camera but incorporates more dynamic range than a camera could actually handle."
(page 168). The other perspective is to create an "painterly" interpretation, as illustrated by the many example images seen on the web.
Bloch illustrates tone mapping of four different HDR images, using the four methods in Photoshop (Exposure & Gamma, Highlight Compression, Equalize Histogram, and Local Adaptation), Photomatix Details Enhance, FDR Tools Compressor, and Artizen HDR Fattal.
The tone mapping that seems to offer the most precise control is Photoshop's "flagship tone mapper" (page 155): Local Adaptation. Bloch's detailed examples show precisely how to work with this approach.
Uwe and Bettina Steinmueller describe (pages 172--182) how they have used Photomatix to produce their stunning images of interiors of abandoned buildings. Also, there is a very helpful, detailed (page 183--211) tutorial by Dieter Bethke, of how he used Photomatix to create three "natural" and two "painterly" images. It is a great resource for getting to know how to use Photomatix and an encouraging illustration of the capability of HDR imaging as a photographic tool.
There is much more in The HDRI Handbook but this is what I have gleaned so far. For me the The HDRI Handbook has turned out to be a wonderful, measured, detailed, and accessible guide to what an HDR > LDR photographic workflow has to offer.
You can discuss this book in this thread on Digital Grin.