Photoblog 2.0

Late in the afternoon of a bright autumn day I arrived in Yosemite Valley. The valley was already in shadow, with only the tops of the surrounding cliffs lit by the sun. I stopped along the banks of the Merced River. With my camera on my tripod, I snapped five exposures of the scene, all at the same aperture (f/7.1). My exposure time varied from 1/15 of a second to 1/125 of a second.

The longer exposures captured the details in the shadows, but blew out the highlights on the cliff tops and the sky, while the shorter exposures rendered the sky acceptably, but lost all nuances in the reflections in the river to darkness. My plan was to combine the exposures to create one image with the best characteristics of each individual exposure.

Yosemite Afternoon, photo by Harold Davis. View this image larger.

HDR

Combining multiple captures to create an image with an exposure range beyond that possible in a single capture is known as High Dynamic Range imaging, or HDR for short. The trick is to compress the extended range into a single image that is pleasing, will display on a monitor, and is reproducible. Note that the exposure latitude within a single RAW capture also gives rise to the possibility of using HDR techniques using different versions of the one RAW file as the input, a technique that I’ve dubbed multi-RAW processing.

Hand HDR

Whether combining different exposures, or different versions processed from a single exposure—or even both these techniques at once—my approach has been to work in Photoshop to use layers, masking, the Gradient tool, and the Paintbrush tool to combine the variants. You can see an example of the results of this hand-crafted approach to HDR in the six-exposure blend that I used to create Yosemite Morning, taken the day after I shot the series used to create the Yosemite image that accompanies this story.

I’ll be writing more about the details of my hand HDR process in an upcoming book—I also teach the technique in workshops—but for now let me mention some downsides: it is labor intensive, time consuming, can look funny if the layers aren’t masked very carefully, and can be close to impossible to achieve in areas that involve complex interconnected details in mixed light.

Photomatix

Since we live in an age that tends to want instant results, most people try experimenting with software the does the HDR for them. I’m no exception, but I’ve been unimpressed with Photoshop’s HDR automation.

So I was excited recently to get to play with Photomatix, which is probably the leading HDR software. The Yosemite image above, and the floral close-up below were both created in part with Photomatix. As you’ll see, the words *in part* are crucial to understanding Photomatix’s place in my scheme of things.

View this image larger.

With Photomatix, HDR generation is a two-step process. You open the images in Photomatix, and the software generates an HDR composite. Then, in a process called “tone mapping”, you tweak the settings used in the mathematical algorithms that reduce the tonal range in the combined image in order to generate a single attractive and reproducible version.

Workflow

As a practical matter, I found Photomatix’s rendering of my RAW files unacceptable. So my workflow went like this: I opened the set of images in the Adobe Camera RAW plugin, applying the same settings to each (experimenting with different RAW conversion settings on each file included is also possible, of course, although it adds more variables and complexity). I opened the files that resulted from these conversions in Photoshop, and saved them in the TIFF format (because Photomatix doesn’t read native Photoshop PSD files).

Next, I opened the TIFF files in Photomatix and generated the HDR composite. As the documentation warns, the HDR image doesn’t start out looking too good, so I worked to tone map it for more attractive characteristics. When I was satisified that the image was the best it could be, I saved it as another TIFF file.

Combined Approach

Some parts of the resulting HDR image were pretty wonderful (for example, the trees on the right). Others, not so good (the sky had a burnt, burnished quality, and the water was murky). I ended up layering-in versions in Photoshop to fix portions of the Photomatix generated image (the same general remarks are true of the floral image that also accompanies this story).

If my workflow with Photomatix sounds like a lot of work, you are right, it was. Then again, I’m happy to work if it helps my work (if you catch my drift).

Life is simpler but less rich

Also, my life would have been simpler in Photomatx if I’d shot in-camera JPEGs. The truth is that the markets for my work often require extremely high resolution, and JPEGs just won’t do. I’m almost never happy with JPEGs compared to my results when I do the RAW conversion.

Conclusion

Paradoxically, I’m left with an appreciation both for what Photomatix can do with HDR, and for the limitations of the software. I’m sure I’ll be using this software to process some portions of my imagery, just as I’m sure that my final versions will require hand work and layer masking with other versions of the files.

If you are an image creator who cares about your craft, the limitations in HDR software amounts to a good reason to learn hand HDR—combining many different versions shot at different exposure times, and processed individually from hand-tweaked RAW conversions, using layer masking—even if you expect to primarily be using automated HDR programs like Photomatix.

As I’ve noted, being digital means you never have to be done. When I originally post-processed the images in this story, I was a little drunk with the power of mult-RAW processing and cross-channel LAB operations. The original scenes were glorious. But I may have over done the post-processing a bit. You be the judge.

View this image larger. Check out the original version.

View this image larger. Check out the original version.

View this image larger. Check out the original version.

Indomitable, photo by Harold Davis. View this image larger.

Winter morning in Yosemite dawned cold with flakes of snow and remnant fog, but the promise of a possible clear day with blue skies.

Provided you carefully archive your files, digital means never having to say you’re done. This is a re-processed version of Golden Wonder with the saturation taken down a bit.

Indomitable. Like the mountains in the winter. Like the digital photographer, always striving to perfect his cache of digital originals.

Half Dome by Moonlight, photo by Harold Davis. View this image larger.

This is a roughly twenty minute exposure during most of which Half Dome was lit by light from the setting moon. I took the photo from Glacier Point, and the foreground landscape beneath Half Dome is deep in moon shadow.

Later, after the moon set, the light grew more uniform and the exposures longer, as in the thirty-minute duration When Stars Rush In.

[Nikon D300, 12-24mm Zoom lens at 17mm (about 25.5mm in 35mm terms), 1,204 seconds at f/8 and ISO 100, tripod mounted.]

Merced Reflections, photo by Harold Davis. View this image larger.

Briefly noted: Along the Merced River the seasonally low water was totally still in the morning, leading to crystal clear reflections.

[Nikon D300, 18-200VR Zoom lens at 50mm (75mm in 35mm terms), circular polarizer, 3 exposures combined in Photoshop from one to six seconds, all exposures at f/32 and ISO 100, tripod mounted.]

Glory, photo by Harold Davis. View this image larger.

Crawling out of my sleeping bag to the sounds of a massive rock slide (here’s the story), I found the Yosemite Valley floor filled with dust. Whatever the cause, the crepuscular rays wrought by the rising sun struck me (and the other observer in this photo) as glorious and spectacular.

Essentially monochrome, I converted the image to black and white in Photoshop using multiple black & white adjustment layers (my process for b&w conversion is partly explained here).

[Nikon D300, 18-200 VR Zoom lens at 32mm (48mm in 35mm terms), 1/400 of a second at f/5 and ISO 100, handheld.]

Starry Night 3, photo by Harold Davis. View this image larger.

Briefly noted: This is another fisheye starry night stacked photo from Glacier Point. This one consists of 12 captures at four minutes and ISO 100 and f/3.2, and one high ISO capture at four minutes and ISO 800 and f/4. The bright purple comes from sensor flaring in the higher ISO capture in the stack. I intentionally left the foreground dark (the way it looks in the individual exposures) rather than trying to blend in a brighter foreground (as in the previous versions).

Yosemite Morning, photo by Harold Davis. View this image larger.

Coming down from a night spent photographing star trails on Glacier Point, I hit the Valley floor about 6AM. I tucked into my sleeping bag, inserted the ear plugs, and slept for a solid hour or so. At about 7AM a deep rumbling noise penetrated the ear plugs and woke me. It was followed by sirens (what’s this, bears dancing on cars setting off their alarms?) and then helicopters.

Sleep fled, and I pulled myself out to see what was going on. A big rock ledge had fallen off Glacier Point into the valley, and right into Curry Village. (Here’s the story. Very frightening if you were staying at Curry, but luckily no one was badly hurt, and the place has largely reopened.)

In the meantime, the Merced River beckoned in the morning light (you can see some of dust from the rock slide in the background of this photo).

To create this image I groggily shot six exposures, at times between 1/13 of a second and a full second. My initial plan was to process these together as an HDR image, using the Photoshop HDR automation. So I converted all six from the RAW using one ACR settings file, and then opening the six files using Merge to HDR. The results looked like garbage, Photoshop didn’t really know which areas to include from which exposure. Next, I tried merging to HDR using the pre-converted RAW files, with more-or-less the same ugly results.

So, it was back to hand combining the six captures using ACR setting variations, layer masking, gradients, and the Paintbrush tool. Computers are great, but sometimes automation sucks, and there’s nothing like doing it by hand.

Related story: Multi-RAW Processing versus Automated HDR.

[Nikon D300, 12-24mm Zoom lens at 12mm (18mm in 35mm terms), 1/13 of a second, 1/10 of a second 1/4 of a second, 1/2 of a second, and one second, all exposures at ISO 100 and f/22, exposures hand combined in Photoshop, tripod mounted.]

Starry Night, photo by Harold Davis. View this image larger

Many of my night photos are created in homage to Vincent van Gogh, who wrote in a letter to his brother Theo, “It often seems to me that the night is much more alive and richly colored than the day.” The star swirl in this image seems particularly van Gogh, so I thought I’d name this one Starry Night, after one of his most famous works.

This photo was taken from Glacier Point in the middle of the night after the moon had set (you can compare the version from the same spot lit partially by the moon).

I made 14 captures using an automated timer, all with my Nikon D200 and 10.5mm digital fisheye at ISO 100 (of course, using a tripod). The first, and longest, exposure was at 8 minutes and f/2.8. The remaining exposures were at 4 minutes and f/4 (to capture the star trails). I then stacked the captures in Photoshop CS3 Extended using the Statistic script set to Maximum mode.

I found that the result included some unfortunate light flaring, as well as some purple sensor burning. So I went back through the 13 four minute captures carefully, and found one with both the flaring and some unintentional foreground light painting. I must have been looking at my other camera with my headlamp on, and lit some of the area of this image by mistake. I fixed the problem by removing the offending capture and restacking the images.

But there were a few areas of the capture that I’d removed that enhanced the image. So I laid it on top of the stacked version, and used a layer mask and paintbrush to paint in these areas.

I also needed to lighten up the foreground. So I reprocessed the eight minute exposure with this in mind, and layered it on top of the other layers, using a gradient to bring out foreground detail.

After this, it was my normal workflow.

Down in the Valley, photo by Harold Davis. View this image larger.

Taken from old Inspiration Point, this image uses a layer mask and gradient to combine a brighter foreground image with a stacked set of captures exposed for the sky and stars.

[All captures Nikon D200, 10.5mm digital fisheye, ISO 100, tripod mounted. Foreground: About eight minutes at f/2.8. Sky: eight captures each at four minutes and f/4.0, combined using the Statistics script in Photoshop CS3 Extended with the mode set to Maximum.]

Leaning into the Stars, photo by Harold Davis. View this image larger.

This is another thirty minute exposure, with the setting moon helping light the foreground. The view is, of course, Yosemite Valley, with El Capitan and Half Dome clearly visible. I took the photo from the Old Inspiration Point, about 1.5 miles up the trail and above Wawona Tunnel View, which is what most people these days think of as Inspiration Point.

You can see car lights in Yosemite Valley. Somewhat more amusingly (and you may have to look closely at the larger size), you can also see the headlamps of climbers bivouaced on El Capitan.

I used a little discrete light painting to illuminate the dead tree trunk in the left foreground.

[Nikon D300, 12-24mm zoom lens at 12mm (18mm in 35mm terms), 1,805 seconds (about thirty minutes) at f/8 and ISO 100, tripod mounted.]

Stars Rush In, photo by Harold Davis. View this image larger.

First, about this photo: here’s some information about the circumstances. Capture data: Nikon D300, 12-24mm Zoom lens at 12mm (about 18mm in 35mm terms), about thirty minutes (1,805 seconds) at f/4 and ISO 100, tripod mounted.

You are invited to a free live webcast: Secrets of Digital Night Photography

DATE Friday, October 17   TIME 10:00am PDT (17:00 GMT)   HOW TO JOIN Register now and we’ll send you a reminder! Meeting link: oreilly.com/go/nightphotos   WEBCAST Secrets of Digital Night Photography   PRESENTER Harold Davis

In a letter to his brother Theo, the great artist Vincent van Gogh wrote, "It often seems to me that the night is much more alive and richly colored than the day." The advent of digital photography has revolutionized the practice of night photography because a digital sensor can record the spectacular colors of the night. These colors are created by light waves in spectrums that are invisible to the naked human eye. For the first time we can truly "see" the world of the night around us.

In this webcast, professional photographer Harold Davis, author of Practical Artistry: Light & Exposure for Digital Photographers (O’Reilly) and creator of the Photoblog 2.0 and Digital Night web sites shows why night photography has become increasingly popular among digital photographers. He demystifies exposure techniques at night, and explains how he post-processes night photos. Following Harold’s presentation, there will be time for a Q&A in which he’ll answer your questions about night photography.

Attendance is limited, so register now. We’ll send you a reminder before the webcast. And please feel free to share this invitation with others.

Date: Friday, October 17 at 10am PDT (17:00 GMT)
Cost: Free
Duration: 60 minutes
Meeting link: oreilly.com/go/nightphotos
Questions? Please send email to webcast@oreilly.com

About Harold Davis

Harold Davis is a photographer and author. His photographs have been widely published, exhibited, and collected. Many of his fine art photography posters are well known, including some recent alternatively processed digital flower images published by New York Graphic Society.

The author of more than twenty books, Harold has written (and illustrated with his photographs) Digital Photography: Digital Field Guide (Wiley), The Photographer’s Guide to Yosemite and the High Sierra (Countryman/W.W.Norton), 100 Views of the Golden Gate (Wilderness Press). He is the lead author of a new series of books about digital photography from O’Reilly Digital Media.

Harold writes the popular Photoblog 2.0, which covers aesthetic, technical, and personal issues related to digital photography. He is the creator of the Digital Night website.

Yosemite by Moon and Star, photo by Harold Davis. View this image larger.

I spent most of Tuesday night on Glacier Point, hoping for Draconid meteor showers but settling for star trails. I brought six batteries and two cameras. I set one of the cameras to automatically capture a series of exposures, with statistical stacking in mind; with the other camera I played.

This one is a combination of sixteen exposures, taken early enough in the night that the moon was still lighting Tenaya Canyon and Half Dome.

Back to my sleeping bag on the Valley floor at about 6AM and time to get some sleep. My ear plugs in place, I was startled awake a short time later by a deep rumbling followed by sirens and helicopters. Bears dancing on cars, setting off car alarms? Investigation showed that a shelf of Glacier Point rock had tumbled down on top of Curry Village. Luckily no one was badly hurt, although they did shut Curry down. Did my night time work disturb the geology?

[Nikon D200, 10.5mm digital fisheye, 16 ISO 100 exposures, foreground at 8 minutes and f/2.8, 15 star exposures at 4 minutes and f/4, tripod mounted, stars combined in Photoshop CS3 Extended using the Statistics script.]

Stars and Milky Way, photo by Harold Davis. View this image larger.

Briefly noted: This is a nine and one half minute exposure from the top of Half Dome looking southwest across Yosemite Park, taken in June 2007. When I was there the Milky Way, shown in this photo as a pleasing blur, was crisp and sharp, but the time exposure and the motion of the heavens rendered it soft focus. The orange light is from the west and is ambient light from the cities of California’s central valley (probably mostly Fresno).

I used this previously unprocessed photo as a demo of RAW conversion the first night of my recent workshop.

[Nikon D200, 12-24mm zoom lens at 12mm (18mm in 35mm terms), 970 seconds at f/4 and ISO 100, tripod mounted.]

Lembert Dome Sunset, photo by Harold Davis. View this image larger.

Briefly noted: As it got darker, I continued to photograph sunset from Lembert Dome. I think the top of the dome adds to the composition in this version.

[Nikon D300, 12-24mm zoom lens at 14mm (21mm in 35mm terms), two exposures (5 seconds and 13 seconds), both exposures at f/8 and ISO 100, tripod mounted.]