Eloquent Images by Gary Hart
Insight, information, and inspiration for the inquisitive nature photographer
Fall color explained
Posted on November 27, 2016
Autumn Morning, El Capitan Reflected in the Merced River, Yosemite
Sony a7R II
Sony/Zeiss 16-35 f4
2 seconds
F/16
ISO 50
Like most photographers in the Northern Hemisphere, my fall color season is about finished. But things are just ramping up along the streets near my home in California’s Central Valley (where winter doesn’t really begin until December, and spring’s first blooms start to pop up at the end of January—sorry). While there’s not a lot for me to photograph in my neighborhood, the opportunity to partake of the visual feast without a camera in my hands is refreshing.
I’m also harvesting the fruits the most intense autumn workshop/travel schedule of my photography life, and appreciating all over again how much I enjoy fall photography. Browsing my autumn images, I’m reminded of the need to understand my subjects. That goes double for the why and when of fall color, a blend of science and myth so intertwined that casual observers often resort to memory, anecdote, and lore to fill knowledge voids with partial truth and downright falsehood.
Innkeeper logic
Show up at at the fall color spot that guy in your camera club said was peaking at this time last year, you might find the same trees displaying lime green mixed with just hints of yellow and orange. Ask the old guy behind the desk at the inn, and you’ll get a head shake and confident explanation that, “The color’s late this year—it hasn’t gotten cold enough yet.” Check into the same inn on the same weekend next year, you might find just a handful of leaves clinging to exposed branches—this time, as the old guy hands you the key, he proclaims, “That hot summer got everything started early—you should have been here last week.”
While “expert” testimony like this sounds like objective truth, it only perpetuates the myths surrounding fall color. Fortunately, science has provided a pretty good understanding of the fall color process to all who want to understand.
It’s all about the sunlight
The leaves of deciduous trees contain a mix of green, yellow, and orange pigments. During the spring and summer growing season, the green chlorophyl pigment overpowers the orange and yellow pigments, keeping the trees green. While this chlorophyl is quickly broken down by sunlight, the photosynthesis that turns sunlight into nutrients that nourish the tree, warmth and long days provide the energy to sustain chlorophyl creation through the summer.
As the days shrink toward autumn, things begin to break down. Cells at the “abscission layer” at the base of the leaves’ stem (the knot where the leaf connects to the branch) begin a thickening process that blocks the transfer of carbohydrates from the leaves to the rest of the tree. Meanwhile, movement of nutrients to the leaves is inhibited as well—without these minerals, the leaves’ chlorophyl production dwindles and finally stops. No longer masked by the chlorophyl’s green, it’s time for the tree’s yellow and orange pigments to shine: Color!
Sunlight and weather
Contrary to popular belief, the timing of the onset of this fall color chain reaction is much more daylight-dependent than temperature- and weather-dependent—triggered by a genetically programmed day/night-duration threshold; contrary to innkeeper-logic, the trees in any given region will commence their transition from green to color at about the same time each year (when the day length drops to a certain point).
Nevertheless, though it doesn’t trigger the process, weather does play a significant part in the intensity, duration, and demise of the color season. Because sunlight breaks down the green chlorophyl, cloudy days after the suspension of chlorophyl creation will slow the coloring process. And while the yellow and orange pigments are present and pretty much just hanging out, waiting all summer for the chlorophyl to relinquish control of the tree’s color, the red and purple pigments are manufactured from sugar stored in the leaves—the more sugar, the more vivid their color. Ample moisture, warm days, and cool (but not freezing) nights after chlorophyl replacement has stopped are most conducive to the creation and retention of the sugars that form the vivid red and purple pigments.
On the other hand, freezing temperatures destroy the color pigments, bringing a premature end to the color display. Drought can stress trees so much that they drop their leaves before the color has a chance to manifest. And wind and rain can wreak havoc with the fall display—go to bed one night beneath a canopy of red and gold, wake the next morning to find the trees bare and the ground blanketed with color.
Of course all these weather factors come in an infinite number of variations that make this year’s color timing and intensity a little different from last year’s and next’s. Despite my need to understand nature’s mysteries, it’s this (perceived) randomness, the impossibility of ever knowing for sure what I’ll encounter, that draws me back.
About this image
Yosemite isn’t an inherently great sunrise location. With most of its views facing east, toward shaded subjects beneath the brightest part of the sunrise sky, sunrise light is difficult here. And without clouds, more the the rule than the exception in California, Yosemite sunrises can be rather bland. But Yosemite’s bland sunrises are more than compensated by the first direct sunlight light visible Yosemite Valley, which starts on the highest points a few minutes after the “official” (flat horizon) sunrise, and progresses over the next hour or so until the valley floor is bathed in sunlight. El Capitan is among the first of Yosemite’s prominent features to benefit from this early light.
I have a mental list of go-to El Capitan views for photographing its first light. Among them is a quiet bend in the river, known affectionately (and unofficially) to photographers as “Tahiti Beach,” with views of Cathedral Rocks, El Capitan, and the Three Brothers. Additionally, the river widens and slows here, providing some of Yosemite Valley’s best reflection opportunities as well.
One morning in the first of this year’s two Yosemite fall color workshops, I guided my group to Tahiti Beach for El Capitan’s first light. Clouds ruled the sky as the first light window opened, but fleeting patches of blue gave me hope. And with the deciduous trees across the river displaying their finest golds and oranges, we weren’t lacking for opportunities in the meantime.
The sun broke through suddenly, spotlighting a thin slice of granite near El Capitan’s summit. Unsure how long the opportunity would last, I moved quickly to compose this wide, vertical frame that emphasized the reflection juxtaposed with a thin veneer of colorful leaves floating at my feet. I reminded myself to heed the frequent admonition I issue my workshop groups: the focal point for a reflection is the focus point for the reflective subject, not the reflective surface. In other words, while the leaves floated in water that was just a few feet from my lens, their focus point was much closer than the infinity focus point of the reflection in the same water. I focused on the leaves, confident that the depth of field provided by f/16 at my 18mm would render El Capitan, the trees, and the reflection acceptably sharp.
Another noteworthy exposure setting in this image is my 50 ISO decision. Though the leaves were completely still, there were slight ripples disturbing the river where most of my reflection lay. Stopping down to f/16, dialing my sensor’s sensitivity to ISO 50, combined with a polarizer carefully tuned to cut the reflective glare on the leaves without diminishing the rest of the reflection too much, allowed a 2-second exposure that smoothed the ripples enough to enhance the reflection.
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A fall color gallery
How do you do that?: Properly expose a full moon
Posted on November 20, 2016
Twilight Moonrise, El Capitan and Half Dome, Yosemite (2014)
Canon Rebel EOS SL1
.4 seconds
Canon is 70-200 f/4L
ISO 100
F11
The problem
Cameras struggle to capture simultaneous detail in bright highlights (the moon) and and dark shadows (the landscape)—capturing one or the other is easy, but both? Not so much. A full moon is daylight bright, but because a full moon rises at sunset and sets at sunrise (more or less, depending on exactly how full the moon is when it rises/sets, and the elevation of the horizon the moon and sun rise/set above), when a full moon is visible, the sky and landscape will be some degree of dark.
The dynamic range problem is compounded by the fact that the darker the sky, the better the moon looks—often by the time a photographer is inspired to pull out a camera to capture the moment, it’s too dark. Additionally, many photographers attempt to photograph a rising full moon on the night it’s at its maximum fullness, which at best provides very little margin for error, and often is just plain too late.
While the advent of digital photography has provided exposure aids like LCD review and a histogram to help us cope with extreme dynamic range, these advances have also caused poor exposure habits. By far the most frequent mistake made by aspiring moon photographers is insisting that the landscape part of their scene as it appears on the LCD look close to what their eyes see, all but ensuring a white blob of moon. Even the trusty histogram lets down moon photographers because the moon is usually too small to register on a histogram—they pat themselves on the back for what appears to be a perfect histogram, completely oblivious to the fact that the moon is hopelessly overexposed.
The solution
One solution to extreme dynamic range is a composite: one image exposed for the moon combined with a second image exposed for the landscape. As tempting as a composite solution seems, my goal is always to capture everything with one click. (But just because we’re doing it with one click doesn’t mean there’s no post-processing required bring out the full range of light my camera captured.) While my technique can work with a jpeg image, you’ll have a much greater chance for success shooting raw. Of course there is a point when the sky and landscape are so dark that a single-click moon/landscape capture becomes impossible and you’ll need to pack up, resort to a composite, or simply stand there and appreciate what you’re witnessing.
Timing
When I plot my moonrises, I look for opportunities in my “lunar sweet spot,” when the sky is dark enough for the moon to stand out in brilliant contrast, but not so dark that I can’t photograph landscape and lunar detail with a single click. That starts around 15 minutes before official (flat-horizon sunrise) and last until about 15 minutes after sunset. That doesn’t mean that I can’t get nice images a little earlier, and squeeze out usable exposures a few minutes longer, but it’s a good rule of thumb.
Getting the full (or nearly full) moon in my “sweet spot” starts with picking the right night—just because your smartphone app tells you the full moon is Sunday night, don’t assume that Sunday night is the best night to photograph it. “Official” sun and moon rise/set always assumes a flat horizon—if you have mountains or hills in the east, you’ll need to wait for the moon to ascend above them, all the while the sky and landscape are growing darker. It helps to know that the moon rises a little less than an hour later each day (this is an average that varies quite a bit with a number of factors)—of the full moon won’t rise above your local horizon until long after the sun is below the horizon, pick an evening one or two days earlier. While the moon is only completely round when it’s full, a day or two earlier will still net you a mostly full moon in much easier light. And if your scene is in the west, your best chance will be a sunrise moonset after the moon is full.
For example, I do a lot of Yosemite moonrise photography, where most of the views are against the eastern sky—depending on where I want to photograph the moon, I may need to be there one, two, or even three evenings before it’s completely full to time its appearance for sunset. In my just completed Yosemite workshop, my group got to photograph moonrise at sunset from four different locations on four different evenings—each evening I found a spot a little higher and farther away from the valley rim so the moon would have to rise quite as high as it did the previous night. On the other hand, in my Death Valley workshop most of our views face west, so we do three or four sunrise moonsets, each one at a spot with a higher horizon than the previous day.
Exposure
The key photographing both the full moon and landscape with detail starts with ignoring the way the picture looks on your LCD because, in a high dynamic range scene, an ideal exposure rarely looks good on the LCD. I repeat: In a high dynamic range scene, an ideal exposure rarely looks good on the LCD. The key is to make the image as bright as possible without blowing the highlights, then adjust the highlights and shadows in post-processing. In most extreme dynamic range situations the key is to completely trust the image’s histogram, but the moon is such a small part of most images, it rarely registers on the histogram—it’s possible to capture a histogram that looks great and moon that’s hopelessly blown (detail-less white).
So if you can’t trust the image or the histogram, what can you trust? I thought you’d never ask. While the histogram is helpful for the landscape part of the scene, when I photograph a full moon, I monitor the moon’s exposure with my camera’s highlight alert feature (“blinking highlights”). Highlight alert manifests in the post-capture LCD image review (though a mirrorless camera displays a highlight alert before I click, too). When engaged, everything in your frame that’s blown out flashes when you review your image, a helpful reminder that the exposure is broken and needs to be fixed. Every digital camera I’ve ever seen offers highlight alert, though some make you burrow deep into the menu system to turn it on and/or hide it on an obscure image playback screen (I’m looking at you, Nikon). If you don’t know how to find the blinking highlights, pull out your camera and manual, click a frame with blown highlights, and read/experiment until you figure it out (it really isn’t that difficult).
Once you’re confident that your camera’s highlight alert is engaged and you know how to check it, you’re ready for the next full moon. Here’s my process for a sunset moonrise:
- Metering in manual mode (because I want complete control of my exposure), I meter the landscape just as I would an ordinary scene. If I can get a good exposure (unclipped histogram) without the moon blinking, I know I’m good for the time being and get to work. Of course for a sunrise moonset, the process is reverse: I subtract light until the moon stops blinking
- The moon’s brightness won’t change, but if it’s a moonrise I’m shooting (always at sunset), I know the landscape will continue to darken, so that exposure that was perfect a few minutes ago isn’t quite so perfect now. As the scene darkens, I continue to add light by increasing my shutter speed in 1/3 stop increments (that is, one click at a time). Each time increase the exposure, I check the moon to make sure it’s not blinking.
- As soon as the moon starts blinking, I’m done adding light—no matter how much darker the scene becomes, giving it more light will blow out the moon.
The more familiar you are with your camera, the more success you’ll have. Different cameras’ highlight alerts engage at different points, and it’s entirely possible (likely even) that you can add a little more light after the first “blinkies” appear in the moon—on my Sony a7RII, I can usually push my highlights another 2/3 to 1 full stop once I first detect blinking and still recover detail later.
A graduated neutral density filter will subdue the bright moon, allowing you to add more light to the landscape without blowing out the moon. Depending on the location, a GND will add 5 to 15 minutes of productive shooting.
Processing
This is not a processing tutorial; I assume you’re shooting in raw mode and have at least rudimentary Lightroom or Adobe Camera Raw skills (though I’m sure if you’re comfortable with any raw processor you’ll be able to figure it out). I’ll just describe a couple of really quick raw processing moves to get you started.
As with all of my images, I try to do most of my full moon image highlight/shadow recovery in Lightroom. But before doing that, I want to get the white balance right. When I open the image in Lightroom, I drag the Vibrance slider all the way to the right (to exaggerate the color cast), adjust away any unwelcome color cast with the White Balance slider, then return the Vibrance slider to 0 (though I reserve the right to nudge it up or down later, when I’m further along in my raw processing).
With the color temperature right, I pull the Highlights slider all the way to the left, and the Shadows slider all the way to the right. This isn’t likely where they’ll end up, but it gives me a good idea of whether I captured recoverable details. If the moon is still blown, or the shadows are still black, I pull the Exposure slider left or right until the missing detail appears. (Tip: Holding down the Option/Alt key while adjusting any exposure slider reveals exactly what is and isn’t clipped.) If I can’t find the detail with the exposure slider, it’s not there.
This is by no means a complete processing workflow—that will vary with too many factors to cover here (including the conditions and exposure decisions at the time of capture, and your own processing style and preferences). But if you exposed the scene correctly, my suggestions will get your overall exposure to the point where you can start working on the rest of what the image needs.
About this image
My favorite spot to photograph a moonrise in Yosemite Tunnel View, which, in addition to being a fantastic view, is far enough from Half Dome to allow a fairly long telephoto. But for this moonrise in 2014 I realized that the moon would appear just a little too late—I needed to be higher and farther back to get the moon before the sky and landscape were too dark. So instead of Tunnel View, I took my workshop group to a vista on the west side of the Wawona Tunnel. While the view here is missing Bridalveil Fall and the bottom half of El Capitan, for our purposes it was perfect. (For this shoot I used my 1.6 crop body to increase the reach of my 70-200 lens.)
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A Full(ish) Moon Gallery
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Supermoon
Posted on November 14, 2016
Supermoon, Half Dome and El Capitan, Yosemite
Sony a7RII
Tamron 150-600 (Canon-mount with Metabones IV adapter)
1/3 second
F/9
ISO 100
The media tends to distort facts and blow events out of proportion. Perhaps you’ve noticed. The latest example is this week’s “supermoon,” an event heralded on TV, in print, and online like the Second Coming. Okay, now for a little perspective. Despite hype to the contrary, a supermoon occurs at least twice, and up to five times, in a year. In fact, our last supermoon was all the way back in October, and the next one isn’t until December.
But, as I’m sure you’ve heard, this month’s supermoon was special, an event the likes of which we haven’t seen since 1946, and won’t see again until 2034. True enough. But exactly how special was it? Not nearly as special as you might have heard: the diameter of the “epic” November supermoon was only one-half of one percent (.57) larger than the October full moon, and four-fifths of one percent (.84) larger than the December full moon—differences that are impossible to discern with the naked eye. Next year we’ll get two moons that are more than 99 percent the size of this month’s supermoon, and last year we had four.
So why was I out taking pictures of the full moon Sunday night? Because I think every full moon is beautiful, regardless of its size, and I take any opportunity to photograph it over my favorite landscapes. Which is also why each fall I schedule a workshop in Yosemite to coincide with the full moon.
Thursday night my Yosemite Autumn Moon workshop group photographed an 82% (of full) waxing gibbous (on its way to full) moon above Valley View at sunset. For Friday night’s sunset, from a quiet beach beside the Merced River we glimpsed through clouds an 87% moon rising just right of Half Dome. Saturday’s sunset found us beneath a magenta sky at Tunnel View to witness the 96% moon ascend between Sentinel Dome and Cathedral Rocks.
The workshop’s grand finale came Sunday night, when we gathered at the Half Dome vista on Big Oak Flat Road. Though I rarely encounter other photographers for any of my moon rise/set shoots, limited parking and tripod space here prompted me to arrive an hour before sunset. That turned out to be a fortunate decision, as within 30 minutes of our arrival the parking lot was brimming beyond full and photographers swarmed the nearby rocks like ants at a picnic.
With an hour to kill, I made sure everyone in my group was ready (but by now, this being our fourth moonrise, they were experienced veterans) and chatted with other photographers nearby. Comparing notes, it seemed that most (all?) of the other photographers had relied on apps like The Photographer’s Ephemeris and Photo Pills to plot the moon’s arrival location and time, while I was the only one clinging to my old fashioned topo map, scientific calculator, trigonometry plotting approach. (I do it this way because I’ve been plotting the moon since long before the apps were available, I feel like I can be more precise, and I enjoy it—not necessarily in that order.)
In the viewfinder of my Sony a7R Mark II, atop my tripod and armed with my Tamron 150-600 lens to enlarge the moon as much as possible, was the composition I wanted—assuming the accuracy of my calculations. The consensus among others seemed to be that the moon would appear from behind Half Dome’s right flank, anytime between 5:00 and 5:10 p.m. I stuck to my guns that the moon would show up at about 5:05, and that it would be straight over the top of Half Dome. While I saw this more as an opportunity to check my plotting method’s accuracy than a competition between methods, it was pretty thrilling when the moon popped into view right on schedule and on target. Take that, technology!
Since the moon didn’t appear until a full fifteen minutes after sunset, the extreme dynamic range (very dark landscape beneath a daylight-bright moon) made this an extremely tricky exposure for anyone (like me) not interested in compositing two images (one with the moon properly exposed, another with the scene properly exposed). To capture this scene with a single click, I closely monitored the pre-capture “zebra stripes” highlight alert in my a7RII and pushed my exposure 2/3 stop after the first hint of the alert appeared. To hedge my bets and give myself processing options, I varied my exposure 1/3 to 2/3 of a stop in either direction (an exception to my standard workflow because the moon is too small to register on the histogram).
The result was a scene that looked quite dark on my LCD, and a moon with no detail. No problem, I reassured myself, for my a7RII’s ridiculous dynamic range. This morning in Lightroom I adjusted the white balance, pulled up the shadows, and pulled down the highlights. In Photoshop I applied a moderate dose of Topaz DeNoise and did a few minor dodge/burn moves to get the image you see here.
One more thing
The size of the moon in this image has virtually nothing to do with the fact that this was a “supermoon,” and virtually everything to do with the fact that I was far enough away to be able to use a 600mm lens. Click below to read about how to capture your own big moon:
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The Moon in all Shapes and Sizes
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Yosemite Autumn Reflection
Posted on November 9, 2016
Autumn Reflection, El Capitan, Yosemite
Tomorrow I start the final workshop in the busiest workshop season I’ve ever had—since mid-August I’ve led 8 of my own workshops, and assisted Don Smith with 2 of his, in four states from Hawaii to Utah. I’ve photographed lots of great stuff, and met many fantastic people, but I’m looking forward to a few consecutive days in my own bed, and an opportunity to share more new images and blog about them.
In the meantime, here’s a Yosemite autumn reflection image from a few years ago. This scene perfectly illustrates a point I try to make to my workshop students: The focus point for a reflection is the focus point of the reflective subject and not the reflective surface. In other words, if you want objects in the foreground (like these leaves) to be sharp, unless you maximize your depth of field, your reflection will be soft.
This is counterintuitive for many, but it’s an easy thing to verify. The next time you find yourself photographing a scene like this, try focusing on the reflection and watch your foreground go soft; focus on the foreground and watch your reflection go soft. The solution is to stop down to a small aperture to maximize your depth of field, and focus toward the back of your foreground subject or subjects. If you find it impossible to get both in focus, it’s usually best to opt for a sharp foreground over a sharp reflection.
For this reflection of El Capitan basking in warm pre-sunset light, I stopped down to f18 and focused on the most distant leaves I could see through my viewfinder (seat-of-the-pants hyperfocal focusing). My small aperture ensured that all the leaves would be sharp (the smaller the aperture, the wider the sharp zone in front of and behind your focus point), while still giving me the most distant focus point possible.
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A Yosemite Autumn Gallery
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Eloquent Images by Gary Hart 