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...
©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.
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…
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