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Review: The HDRI Handbook. "Don't throw it all away yet!"
dandill
Registered Users Posts: 102 Major grins
The HDRI Handbook: High Dynamic Range Imaging for Photographers and CG Artists
by Christian Bloch
http://www.amazon.com/exec/obidos/ASIN/1933952059/dandillcom
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.
The HDRI Handbook guides photographers to the watershed that HDRI is.
by Christian Bloch
http://www.amazon.com/exec/obidos/ASIN/1933952059/dandillcom
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.
The HDRI Handbook guides photographers to the watershed that HDRI is.
Dan Dill
"It is a magical time. I am reluctant to leave. Yet the shooting becomes more difficult, the path back grows black as it is without this last light. I don't do it anymore unless my husband is with me, as I am still afraid of the dark, smile.
This was truly last light, my legs were tired, my husband could no longer read and was anxious to leave, but the magic and I, we lingered........"
Ginger Jones
"It is a magical time. I am reluctant to leave. Yet the shooting becomes more difficult, the path back grows black as it is without this last light. I don't do it anymore unless my husband is with me, as I am still afraid of the dark, smile.
This was truly last light, my legs were tired, my husband could no longer read and was anxious to leave, but the magic and I, we lingered........"
Ginger Jones
0
Comments
Do you mind if we add this to the Book Reviews?
Photos that don't suck / 365 / Film & Lomography
"It is a magical time. I am reluctant to leave. Yet the shooting becomes more difficult, the path back grows black as it is without this last light. I don't do it anymore unless my husband is with me, as I am still afraid of the dark, smile.
This was truly last light, my legs were tired, my husband could no longer read and was anxious to leave, but the magic and I, we lingered........"
Ginger Jones
RockyNook, the publisher, has published a number of excellent texts re: digital photograhy and post processing of digital images.
Moderator of the Technique Forum and Finishing School on Dgrin
There's a mini review of it, and other must have books here:
http://photoshopnews.com/2007/12/21/a-book-roundup-of-2007/
Author "Color Management for Photographers"
http://www.digitaldog.net/
Thanks.
"It is a magical time. I am reluctant to leave. Yet the shooting becomes more difficult, the path back grows black as it is without this last light. I don't do it anymore unless my husband is with me, as I am still afraid of the dark, smile.
This was truly last light, my legs were tired, my husband could no longer read and was anxious to leave, but the magic and I, we lingered........"
Ginger Jones
Here are some details based on working with the methods described.
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.
First, combine bracketed exposures to create an HDR image. Block focuses on using Photoshop or Photomatix for this step.
Second, make use Photoshop to make basic adjustments to the HDR image. These are: cleanup with the Clone Stamp, white balancing (done in two steps, differently than in LDR images), frame/perspective correction (using Free Transform), sharpening (using the HDR dynamic range to visually quantify proper sharpening), and color correction. None of these need to be done to the HDR image, but Block discusses the advantages of doing so, *before* converting to LDR.
Third, tone map the HDR image into an LDR image. For me, this is the core, creative part of HDR imaging in photography. Bloch distinguishes two perspectives.
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. The mapping is crafted by adjusting a toning curve to set black and white points, and to control local and global contrast. 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.
"It is a magical time. I am reluctant to leave. Yet the shooting becomes more difficult, the path back grows black as it is without this last light. I don't do it anymore unless my husband is with me, as I am still afraid of the dark, smile.
This was truly last light, my legs were tired, my husband could no longer read and was anxious to leave, but the magic and I, we lingered........"
Ginger Jones
The comparison below is my first go at using HDR to improve a "natural" LDR image (of the snow in central Vermont last week).
The HDR was made from five 1 EV bracketed images taken using a tripod to maintain registration.
The first iamge is a reduced jpg of the "best" single exposure, capture sharpened in Camera Raw, and with some Clairity applied.
The second image is the LDR mapped using Photoshop Local Adaptation. The HDR image was Smart Sharpened before the tone mapping. Then I used Camera Raw to apply Clairity to the LDR tif.
This differences are subtle (except for the cloning out of a snow stake and also the vertical streaking on the windows in the HDR image) but clear (on my screen), even at reduced size (1200 wide versus 3087 of original). I hope they show in this post.
I worked on the contrast in the tress by the pond bench, in the details of the plowed snow thrown on the snow bank in the lower right window pane, and the visibility of the (out of focus) temperature gauge on the right edge.
Here is the Local Adaptation toning curve that I used.
Finally, I worked to restore what little color there was in the reeds and evergreen fronds in the lower middle left, and to bring up the color in the window frame, by converting to Lab and then applying very steep Margulis "Canyon" curves (see Photoshop LAB Color) through an inverted luminosity mask, curved to emphasize just the darks (and so protect the snow).
"It is a magical time. I am reluctant to leave. Yet the shooting becomes more difficult, the path back grows black as it is without this last light. I don't do it anymore unless my husband is with me, as I am still afraid of the dark, smile.
This was truly last light, my legs were tired, my husband could no longer read and was anxious to leave, but the magic and I, we lingered........"
Ginger Jones
Thanks for the information and the posting.
Mike
Mike Mattix
Tulsa, OK
"There are always three sides to every story. Yours, mine, and the truth" - Unknown
Author "Color Management for Photographers"
http://www.digitaldog.net/
What I'd like to understand is why the color in the central exposure didn't come through the merge to HDR in the first place. More to learn.
"It is a magical time. I am reluctant to leave. Yet the shooting becomes more difficult, the path back grows black as it is without this last light. I don't do it anymore unless my husband is with me, as I am still afraid of the dark, smile.
This was truly last light, my legs were tired, my husband could no longer read and was anxious to leave, but the magic and I, we lingered........"
Ginger Jones
Not shape, a strange magenta "glow" around the round thingee.
I think the image looks much better as a more monochromatic piece.
Author "Color Management for Photographers"
http://www.digitaldog.net/
"It is a magical time. I am reluctant to leave. Yet the shooting becomes more difficult, the path back grows black as it is without this last light. I don't do it anymore unless my husband is with me, as I am still afraid of the dark, smile.
This was truly last light, my legs were tired, my husband could no longer read and was anxious to leave, but the magic and I, we lingered........"
Ginger Jones
Got it: I had left WB automatic, so each of the captures had a slightly different white balance, exacerbated by the windows being covered with a film to cut down UV light, and that resulted in auto WB being off with respect to the outside light.
To get a common, correct white balance, I loaded all of the images (used in the merge to HDR) into Camera Raw, use the "best" single image to set the WB using a neutral object from outside the windows, and then synchronized all of the other images to this setting.
Redoing the merge to HDR with these adjusted images sorted out the color.
"It is a magical time. I am reluctant to leave. Yet the shooting becomes more difficult, the path back grows black as it is without this last light. I don't do it anymore unless my husband is with me, as I am still afraid of the dark, smile.
This was truly last light, my legs were tired, my husband could no longer read and was anxious to leave, but the magic and I, we lingered........"
Ginger Jones
Photos that don't suck / 365 / Film & Lomography
I just came across the following clear, detailed tutorials by Ferrell McCollough.
Bracketing & number of exposures
Tone mapping using Photomatix
Postprocessing with Photoshop
On the Photomatix email list he mentioned his upcoming book Mastering HDR Photography, due June, 2008.
"It is a magical time. I am reluctant to leave. Yet the shooting becomes more difficult, the path back grows black as it is without this last light. I don't do it anymore unless my husband is with me, as I am still afraid of the dark, smile.
This was truly last light, my legs were tired, my husband could no longer read and was anxious to leave, but the magic and I, we lingered........"
Ginger Jones