Issues in HDR Tone Mapping

Candyland Sky
©Joe Bridwell
Convoluted, chocolaty red rock shapes contain subdued white sandstone stringers. Long sky cloud stringers subtly emphasize the point-counterpoint red rock surface. I find God's handiwork quite artistic...

What's the Best HDR Software for Noise Reduction and Chromatic Aberration? We've compared Photomatix and CS4 for Magic Hour HDR. When you use Lightroom to remove noise and chromatic aberration before HDR, Photomatix returns an image with chromatic aberration - though you requested it be removed.
CS4 provides a clean image; although processing may be more convoluted, when the end result is printed on large printer, I feel it's worth using CS4.
We describe the entire CS4 process to achieve complete tone mapping. It's an experimental but reproducible process; one where you learn more and get better as you do more of it.

HDR Capture
Five high dynamic Range images were captured at +/- 2EV. The negative EV range contained Noise; images also contained Chromatic Aberration. One might expect such behavior when shooting at Magic Hour, that hour around dawn and dusk.

CS4 vs. Photomatix
With Lightroom 2, we globally eliminated dust smudges, reduced noise, and reduced chromatic aberration for each image before submitting them for high dynamic range processing.
When Photomatix created a 32-bit Tone Compressed HDR result from these images, chromatic aberration was present. When CS4 created a 32-bit Local Adaptation HDR result, chromatic aberration was absent.

Tone Mapping in Several Stages
When CS4 receives images to Merge to HDR from LR2, it may take a little while to create a 32-bit file. We recommend you save that 32-bit file because you may want to work with it later.
Image> Mode> 16 Bit brings up the HDR conversion routine in CS4 to create a 16-bit tif file. Use the drop-down menu to choose Local Adaptation, set Radius about 90 pixels, choose Threshold about 1%, and carefully map the Tone Curve. Martin Evening has pointed out that tone curve mapping of an HDR image is both complicated and different from the normal tone curve choices for a single image.
The HDR result may same bland; little distinctive color, sort of soft.

Mask Sky and Ground with Color Range
Magic Hour is enhanced by dramatic clouds. It's usually easier to select sky and clouds to create a mask between sky and ground. For this task, I use Color Range. By setting small values for Fuzziness and Range, the mask selection usually fits the boundary fairly well.
It's a very good practice to examine the image at 2:1 (200% zoom). Although keystroke techniques differ between LR 2 and CS4, this scan size lets you look for various effects which would be immediately apparent on a large print. In particular, you quickly get to see if Color Range selected portions of the sky and ground which need to be corrected in the mask.
When you've completed the Sky mask, duplicate channel, invert the channel, and name it Ground.

Hue/Saturation Color Adjustments with Masks
Create 2 adjustment layers using Hue/Saturation. Attach the Sky mask to one, then find the right sky color using Hue. Attach the Ground mask to the other, then find the right ground color using Hue.
When appropriate colors are found, vary Saturation and Lightness until the colors reflect nearly true colors from the 0 EV image on the initial capture.

Final Tone Mapping in Lightroom 2
Lightroom 2’s close connection with Adobe Camera Raw provides easy Basic, Tone Curve, and Details tabs for final, accurate touch up. We pay particular attention to contrast, clarity, and vibrance. We apply the landscape preset then carefully enhance the masking portion of sharpening to finalize our image.

Finale…
I thank Bob Weber for a very enlightening session where, among many other topics, we dealt with fringing and correction of chromatic aberration. It prompted me to prepare a more detailed workflow describing how to use LR 2 and CS4.

Enjoy…

1st Impressions ~ Raw Workflow - P II

Adjustments panel with favorite Curves, Vibrance, HSL, Gradient, and Adjustment Layer Clipping Mode controls underlined.  These controls perform 90% of my raw workflow.

We continue our examination of Adobe Photoshop CS4 for Photographers by Martin Evening.

Why Shoot Raw?
In Real World Camera Raw for CS4, Fraser and Schewe ask and answer this important question.  When shooting raw, you get to control scene interpretation.  With raw, the only on-camera settings that have an effect on captured pixels are ISO speed, shutter speed, and aperture.
Everything else is under your control when you convert the raw file.  You can reinterpret the white balance, color metric rendering, tonal response, and detail rendition (sharpening and noise reduction) with a great deal of freedom.  Within limits of exposure and linear capture, you can even reinterpret the basic exposure itself, resetting white and black points.
In essence, you’ve captured everything the camera can deliver.  So, you have much greater freedom in shaping overall tone and contrast for the final image.  For me, this freedom translates to a big question,
"What is an optimum workflow to properly Tone Map the final product... be it HDR, panorama, or just a single provocative image."

Adjustment Panel
Camera Raw 4.6, commonly associated with Photoshop CS3, has eight sub panels in the Adjustment panel.  These workhorse panels are Basic, Tone Curve, Detail, and HSL.  You can mess with everything from white balance to sharpening and noise reduction - such adjustments become the heart of your workflow.  The same panel is available in Camera Raw 5.3 for CS4; its in Camera Raw’s tools and the new Adjustments Panel where Tone Mapping really becomes exciting and your workflow really takes off...  I explicitly refer to non-destructive local tools Adjustment Brush and Graduated Filter.

Kelby's Lightroom 2 Develop Module Workflow
The Develop panel in Lightroom 2 has several major elements.  Basic, Tone Curve, HSL/Color/Grayscale, Split Toning, Detail, Vignettes, and Camera Calibration comprise the most commonly used sequence of major development elements.  This particular order is specified in Lightroom 2’s Develop Module.  Kelby reviews each successive element in The Adobe Photoshop Lightroom 2 book for digital photographers in a sequential workflow.
I find Basic, Tone Curve, HSL/Color/Grayscale, Detail (Sharpening and Noise Reduction), and Camera Calibration my workhorses for raw development, converting me to the more standard pro’s view that some 80% of my development work can be done in Lightroom.  Kelby advocates 90% or more...

From this viewpoint, I approached Evening’s Adobe Photoshop CS4 for Photographers seeking the simplest workflow to quickly enhance my already full plate.  What additional factors do I need to learn to make CS4 quickly a part of an already more encompassing workflow?

Evening’s CS4 Raw Workflow Editing
Sharpening
During capture, image sharpness can be loss to optic quality, image resolving ability of camera sensor, and the anti-aliasing filter which covers the sensor.  Captured images can be less sharp than they should be.
Capture sharpening is one of the first things you do to an image before you start retouching.  If you shoot raw, capture sharpening must be done either in the raw processing program (Lightroom 2, Bridge CS4) or afterwards in Photoshop.  With advent of Camera Raw 4.1 (CS3), new sharpening controls rewrote the rules completely.  Now, it makes sense to do capture sharpening at the raw processing stage before you open images in Photoshop.
The Detail panel springs from work of Bruce Fraser in Real World Image Sharpening with Adobe Photoshop CS2.  With its inclusion, both Lightroom 2 and Adobe Camera Raw 5.3 are at the forefront of sharpening.
Take note - most of the rest of the workflow we describe is in Photoshop in the Adjustments panel.  In order to proceed from sharpening to tone mapping, one needs to involve Bridge and Photoshop.  This is not the most efficient workflow method.
In Camera Raw 5.3, Bridge CS4 nests Sharpening and Noise Reduction in a separate Detail panel.  Since I usually shoot landscapes, I will apply the sharpening landscapes preset to the raw file in Lightroom 2.

Adjustments Panel controls
There are several advantages to the adjustment layer approach:
1.    Adjustment layers are not permanent.  If you want to undo an adjustment or readjust settings, you can do so at any time!
2.    Adjustments remain 'dynamic'.
3.    Adjustments can be masked; apply the associated layer mask and refine using the Masking Panel.
4.    Best of all, adjustment layers are no longer restricted to a modal state (you have to double-click the layer first to access adjustment controls).
You have the potential to quickly access adjustment layer settings anytime you wish.  If you click on an adjustment layer, you can paint on the layer mask, adjust layer opacity and blending options, with full access to adjustment controls.
Immediately beneath iconic options, the Adjustments Presets list can be quite helpful.

Are Curves ALL You Need?
"I'm a firm believer in trying to make Photoshop as simple as possible.  With 22 items listed in the Image Adjustments Menu, you can achieve almost all image adjustments you need by using just Curves and Hue/Saturation."

A. Sample image to set black point. B. Sample image to set gray point. C. Sample image to set white point. D. Edit points to modify curve. E. Draw to modify curve. F. Curves type drop-down menu. G. Set black point. H. Set gray point. I. Set white point. J. Show clipping. (See the Finger; it’s our elusive Targeted Adjustment Tool.)

Masks Panel controls

Mask Preview, Density Slider, Feather Slider, Convert Master Selection, Apply Mask the Layer, Enable/Disable Mask, Pixel Mask Mode, Vector Mask Mode, Refine Mask Edges, Make a Color Range Selection, and Invert the Mask.

Adjustment layers are added to the layer stack with a pixel mask attached.  The density slider adjusts the mask density (opacity).  The feather slider softens the mask edges.  The color range button let you make selections based on colors in your image.  You can select colors to add or subtract from color range selection and see results applied directly as a mask.  The faint circle on the bottom left converts a mask to a selection.  The triangle applies a mask to the layer. 
Last, but not least, the vector mask button (upper right) provides surprising strength.  A vector mask is just like an image layer mask, except the mask is described using a vector path.  The mask can be edited using the pen path or shape tools.  It is resolution independent.  It can be transformed or scaled in size without any loss in quality. 
Color Range - when I was a boy, CS Forester wrote the Hornblower series.  Horatio Hornblower entered the British Navy as midshipmen, finally mustering out as Commodore of the Fleet.  In days of sailing frigates and ships of the line, many a cold dawn watch occurred at the fore top mask.
I'm reminded of this vivid history when I watch Martin Evening take a picture of a sailing ship, use Color Range to select the delicate intricacies of mast and rigging, make a Color Range mask, then skillfully change the azure sky background to a more passionate, cloudy sky.  This particularly striking example shows that a Color Range mask can handle incredibly complex images, create a superb mask, and elevate your photography to a new plane.

Conclusions...
The big advances in CS4 are the Adjustments and Masks panels!  It's like one-stop shopping; instead of going to many dialog boxes, these panels immensely speed your workflow.  Unfortunately, if you prefer sharpening and don't have Lightroom 2, the combination of Bridge and CS4 put sharpening tools in Adobe Camera Raw whereas the rest of this workflow is in CS4.
Evening does touch on Lightroom.  But, he wants to present Bridge and CS4 as a package.  Yet, he also uses Lightroom 2 as his search database for all photos. I do find his examples to offer additional insight into CS4 image processing.  And, I anticipate the Schewe and Evening Adobe Photoshop CS4 for Photographers – Ultimate Workshop will emphasize advanced workflow solutions.

As for me, I plan to use Lightroom to for pre-development, then use the Adjustments and Masks panel in CS4 for the fine, intricate steps to finalize my images.
My apologies for a longer than normal blog entry; it seemed important to illustrate the pros and cons, then reduce workflow to its simplest elements...
Enjoy...

1st Impressions ~ Photoshop CS4 for Photographers

”Pixel Genius is a company I have direct involvement with and is thus mentioned several times in the book.  Pixel Genius was the brain child of Jeff Schewe, Bruce Fraser, Mike Skurski, Andrew Rodney, Seth Resnick and myself - we produced plugins for Adobe Photoshop and Photoshop Elements.”  

Martin Evening, Oct., 2008.

Now, that’s truly walkin’ in tall cotton… and it’s clearly shown in Martin’s exciting new book!

How Have I Learned Photoshop?
Real-World Adobe Photoshop Camera Raw CS2 & CS3 (Fraser and Schewe) were very important for my learning steps in Photoshop.  I also bought Photokit Sharpener from Pixel Genius.
With advent of CS4, I questioned the need to get RWAPCR CS4.  With Evening's new CS4 book (it's been in my library ~ 36 hours; I’m scoping out image sequences), I hoped it would contain most of what I could've learned from RWAPCR CS4.  However, Evening only discusses changes through ACR 5.0. 

Evening’s New Book
For me, its 2 hours of movies about new features which emphasize why CS4 is a significant upgrade.  After acclimating to Kelby’s well-written Lightroom 2 book, these movies quickly show me what I need and where to go in the book for continued growth into CS4.  To hedge slightly, examples where Evening might use 7 curve adjustments with associated masks are rare.  I'm betting that an in-depth, penetrating, and more informative 'pixel mafia’s' influence will also continue to dominate, step-by-step, in Adobe Photoshop CS4 for Photographers - Ultimate Workshop, Schewe and Evening.
With Lightroom 2 experience, I purchased CS4 to use Adobe Camera Raw’s 5.X local adjustment brushes, content aware scaling, and advanced masking.  I'd read early but limited reviews of What's New in CS4.  Last night's brief perusal of the Adjustment Panel convinced me Evening is entitled to be among 'pixel mafia'. 
Adjustment layers are now managed via an Adjustments Panel. This new setup is a huge deal!  Doing away with modality of Adjustments dialogs really sings… modality means the seemingly prolonged series of keystrokes to make a CS3 curve change occur.  Now, you can now add adjustment layers with immediate access to adjustment settings.  Imagine you have three different adjustment layers applied to an image. As you tweak adjustments for an adjustment layer you can also go directly to Layers panel and adjust layer blending mode. The scope to work faster and more efficiently will definitely enhance your workflow, leaving more time to be out shooting.

Hot Stuff
For me, some of the meat of this book lies from pages 292-310 in Image Editing Essentials.  Evening covers Curves Adjustment Layers, Choose a Larger Sample Size, and Targeted Adjustment Tool.
When you click on the targeted adjustment tool and move the cursor to the document window, you can parametrically modify the curve.  What does that mean?
If you drag the mouse pointer up-and-down, it will simultaneously move the newly added curve point up and down.  So, you can easily make specific tonal areas lighter or darker.  When you've increased the sample size, this makes an incredible slider application for adding local, nondestructive contrast right on your image. 

Mask Panel
Now, for some of the potatoes!  Pages 330-337 provide a brief introduction.  Although there are eight controls on the mask panel, for fine masking of windblown hair, etc., the newly enhanced Color Range is perhaps most important.  While not as powerful in CS3, a reinvigorated color range now enhances your capabilities.  Evening shows a challenging long exposure of light reflection on a picture of tunnels.  The color range mask creates a very good control.
A sailing ship mast against the azure sky, with its complex guylines and halyards, is way more interesting!  On the video and pages 440-443, Evening takes Color Range masking to a limit.  By compositing two images, he places dramatic clouds behind the mast - leading you to wonder at the seeming simplicity of such a complicated composition.

Attention to Lightroom 2

"Ever since Adobe Photoshop Lightroom made its first appearance as a beta product, I've been using Lightroom in studio and on location.  I now use it all the time to import images from cards as well as when shooting in tethered mode.  I've stopped using Bridge completely at the import stage.  Lightroom cataloging features allow me to search and navigate master original files." 
After making this statement, Evening then describes an import workflow for Lightroom in 4 pages.  Otherwise, he devotes many pages to Bridge, which he admits was klunky for CS3.

There Are Always Cons...
I like to scan a book before I start diving in to read.  To do that, I always want an accurate Table of Contents.
While searching for Targeted Adjustment Tool, let me put this in a simple way, "Martin, you and your guys didn't put a lot of attention to a really up-to-date Grade A table of contents.  I spent a couple of hours waffling around before I finally settled down to just read the book - rather than quickly going to the new areas which would enhance my growth."
At 677 pages – this book’s like a 2nd hand 5# weight (actual – 3.5#).  So, while inculcating exciting insightful tidbits, you’re also strengthening that throwin’ arm.
BTW – better have a rectangular magnification glass; some of the images from Photoshop are difficult to read.

Seriously…
Pathways of Light contains a section called Brain Food.  Brain Food is inspired by a simple fact; without a good book describing how to use it, new software can really be a real p__ i__ t__ a__ to learn.

Adobe Photoshop CS4 for Photographers has become my choice to learn CS4... there is a lot of in-depth information I did not cover.