2. High Dynamic Range Photography - Photomatix Pro

Pages:  1 2 3 4
Lightbox (41) Tags: digital-camera   photography   software Posted: Feb. 28, 2009 by Serge
7. The resulting photo obtained with the Details Enhancer method of tone mapping 8. Photomatix Pro 3.1 - 100% crop from EV 0 original 9. Photomatix Pro 3.1 - 100% crop from Details Enhancer tone mapping 10. The resulting photo obtained with Tone Compressor method of tone mapping 10. Top - the original image (EV 0), middle - Photomatix Pro 3.1 - HDR Tone Compressor tone mapping, bottom - Details Enhancer tone mapping
An example of the exaggerated HDR tone mapping resulting in special type of look that many people associate with HDR. Some love it, some hate it. An example of the exaggerated HDR tone mapping resulting in a special type of look that many people associate with HDR. Some love it, some hate it.

If you follow discussion groups on HDR, it won't take a lot of time to notice that Photomatix Pro (developed by HDRSoft) is one of the most popular software tools used for HDR processing. Photomatix Pro is a stand-alone program that runs on Mac OS X and Windows 98/Me/2000/XP/Vista. One Tone Mapping method is also available as a plug-in of Photoshop CS2/CS3/CS4. The price is $99 for Photomatix Pro and $119 for Photomatix Pro with plug-in. Plug-in along is $69.

To actually understand if you need this plug-in you need to learn more Details Enhancer method for tone mapping. As you will see below, Details Enhancer offers some additional tone mapping options that allow quick alteration of images beyond the DR enhancements. If you are one of many photographers who are pursuing this type of processing (I also have to mention that there are enough of those who hate it), you may find it convenient to use Details Enhancer within Photoshop CS2/CS3/CS4 directly.

One of the nice things about Photomatix is its power combined with simple and intuitive controls. When you start, you are offered several options: Generate HDR Image, Exposure Blending and Batch Processing. If you have already and HDR image (save in one of the special HDR formats), you can also open it in Photomatix for tone mapping.

1. "Create HDR Image" screen 2. "Create HDR Image" options 3. "Exposure Blending" interface 4. "Batch processing" interface 5. Tone mapping, Details Enhancer interface 6. Tone mapping, Tone Compressor interface

Generate HDR Image option is a "true" way of HDR since it produces an HDR image that you can save. This gives you additional flexibility; for example, you can open it in Photoshop and process as a 32-bit HDR image which is pretty much a powerful thing.

Exposure blending is another method of combining images with various EV where highlight details are taken from the underexposed photos and shadow details from the overexposed ones. However, it does not result in creating a special HDR image that can be stored in a special format. One of most practical differences for many photographers between exposure blending and generating an HDR Image is that the former creates significantly less noisy output basically preserving the noise level of source images. On the other hand, images resulting from "true" HDR image appear as if taken with significantly higher ISO. For example, if source images were taken with ISO100, the resulting finished image (with tone mapping done) may look like taken with ISO400 (see 100% crop from EV 0 original and 100% crop after final tone mapping). For Photomatix users, another practical difference is that the tone mapping process (that follows HDR image generation) provides significant controls over the final look of the output (among other things these controls help reduce noise). Whereas Exposure blending settings are rather limited.

Batch processing feature is perhaps another reason for the popularity of Photomatix. This feature provides a nice interface for processing several groups of source images at once and allowing for significant time savings. Groups of images can be arranged in sub-folders (where each sub-folder holds photos for one picture) or in one folder where there are equal numbers of source images relating to one final image (you have an option of specifying this number). However, on a substantive side, batch processing uses the same processing algorithms.

Generating HDR Image

In this article, I describe only the Generate HDR Image processing as offering the most interesting options in producing final results. It starts with a dialog box to select source files. My recommendation while using Photomatix is to work with images taken not more than with two EVs (i.e. two full-stops). Images with more than 2 EV result in Photomatix in a lower quality final output.

Once source files are selected, you may adjust Generate HDR options. Essentially, that's it as far as the creation of an HDR image is concern. By the way, HDR generation is significantly faster than in CS3. And as expected HDR image is pretty much useless since it cannot be displayed by the monitor. Next step is to do tone mapping.

Tone mapping

Photomatix offers two methods of tone mapping: Tone Compressor and Detail Enhancer available as two tabs in Tone Mapping window. Try both tone mapping methods with your image. Do not forget about the Loupe tool to see details. This is important since final result often depends significantly on such details.

The Tone Compressor method produces a more "photographic" look and works on the whole picture relying on the pixels' intensity and global image characteristics.

It offers simple and intuitive controls:

  • Brightness
  • Tone Range Compression (works similarly to the "Shadow/highlight" tool in Photoshop)
  • Contrast Adaption (with Increase flattens colors but makes them more vibrant)
  • White and Black Point (clips whites and blacks similar to Levels in PS)
  • Temperature (warms or cools the picture)
  • Saturation (makes colors more vibrant)

I bet the Details Enhancer method of tone mapping is one of the reasons Photomatix is so popular. It works locally taking into account not only the pixels' intensity and image characteristics but also individual pixels' surroundings to create more illustrative look so many people are after. Same way, it's the reason most HDR haters are so loud about the unnatural look of HDR processed photos.

You can find an example of an HDR image produced with Details Enhancer tone mapping with rather extreme settings at the top of this page. To tell the truth, I also added some additional "enhancements" to the picture in Photoshop (increased local contrast with Unsharp Mask, enhanced even more colors, added lightning effects and "turned on" both lamps). At the same time I left untouched some artifacts like halos typical for the extreme HDR processing. The result is not very naturally looking picture. Do you like it? After all, the beauty is in the eye of the beholder!

Details Enhancer offers the following controls:

  • Strength (controls the strength of local contrast enhancements. Use lower strength values for regular photo look)
  • Color Saturation (makes colors more vibrant)
  • Luminosity (controls the overall brightness of the image and details in shadows)
  • Light Smoothing (controls contrast variations throughout the image: higher values produce more natural look; lower values produce kind of illustrative look similar somewhat to the High Pass filter in Photoshop)
  • Microcontrast (sets the level of enhancement of local details and their contrast especially on edges )
  • Tonal Settings controls: White Point, Black Point and Gamma (work Levels tool in Photoshop; gamma controls the brightness of mid-tones and should be coordinated with Luminosity settings
  • Color Settings controls: Temperature, Saturation Highlights, Saturation Shadows. Temperature warms or cools the picture; whereas other two controls unique to allow for quick adjustment of saturation in respective areas.
  • Smoothing Settings controls: Micro-smoothing, Highlights Smoothing, Shadows Smoothing, Shadows Clipping. All these controls help deal with noise. However, the Micro-smoothing, when used at low value settings can significantly alter the image acting as an "art" filter. Other three controls are also unique to Photomatix. For example, Shadows Clipping can drastically reduce noise in shadows by clipping them. A note about Highlights Smoothing - it can be used to combat halos often appearing after adjusting Luminosity and Light Smoothing.

Both tone mapping methods offer some additional controls such as the buttons in the bottom frame to undo or redo settings, restore the default settings, as well as load and save presets. The Tone Mapping Preview on the right shows a preview of the final tone mapped image. The size of preview can be adjusted using the radio buttons on top. Remember that the preview is just an approximation and final results may differ especially with the Details Enhancer tone mapping method.

Writing about Photomatix, I cannot but mention its Web site. In addition to purchasing and downloading the software, it contains sections with extensive information on HDR, tips and video tutorials as well as collection of useful links to third party HDR resources. You can also use a demo version of Photomatix: it's fully functioning with the only limitation of placing watermarks on all generated output.

Part I - High Dynamic Range Photography Simplified
Part III - High Dynamic Range Photography - "HDR Look" and Pseudo HDR vs. HDR
Part IV - High Dynamic Range Photography - Qtpfsgui

Pages:  1 2 3 4

You May Also Like

1. High Dynamic Range Photography Simplified
 High Dynamic Range imaging (HDRI or simply HDR) has become recently a very popular technique of post-processing photos to enhance them and achieve a desired artistic effect. It attempts to ...
4. High Dynamic Range Photography - Qtpfsgui
 No serious enthusiast of HDR can skip Qtpfsgui - an open source graphical user interface application that provides a workflow for HDR imaging. This review of the package is focusing on ...
3. High Dynamic Range Photography - "HDR Look" and Pseudo HDR vs. HDR
 Another article in a series dedicated to HDR photography addressing some confusion regarding actual HDR as opposed to various techniques used to enhance the DR and tonal properties of photos.