Quiz time!

Al Denelsbeck



All right, so today marks the second anniversary of my first blog post, with this being the 148th actual post. No, this doesn’t call for a celebration, because I’m not only not into relatively meaningless milestones, I expected to be seeing more visits than this by now. Ah well.

So instead, I’ll provide a quiz question (mostly because I feel some need to put something up here today.) Relying on this chapter, refer to the image at top. I was waiting for the gusting wind to blow some loose snow across the frame to lend a little atmosphere to the composition, so I was holding the same framing in the viewfinder for several minutes. Can you tell me why, in order to do this, I had to keep shifting my vantage point?

The answer lies immediately below – click and drag across the blank space with your cursor, highlighting the text to read the answer. I’d offer a prize to the first person to e-mail me with the correct answer, but considering the dearth of comments, I might be waiting a while. So instead, here’s the explanation:
The moon and sun both move across the sky by their own width in 150 seconds, just two and a half minutes, so the moon was continually moving behind the tree branches. I had to keep moving to my left, and slightly backwards, to keep the moon in roughly the same position in relation to the closer branches.
When you’re in the northern hemisphere and facing south, the moon moves to the right (west of course,) in this case, towards the dark side. Once it passes its new (blank) phase, the sunlit side will exchange and be the reverse of what is seen here.

Did you get it?

Whether you did or not, check this out the next opportunity you get – its a neat thing to watch happen.

Thanks for visiting!

Ya work with what ya get

Al Denelsbeck


On christmas evening, the threatened storms rolled in, giving us the third snowfall of December. This is a fairly rare occurrence for this latitude, where we usually don’t get snows until January at least, and often not this heavy. While I learned how to drive in central New York, I don’t have a vehicle ready for winter driving, so when the roads get treacherous, I stay home. In this case, I’m at The Girlfriend’s Place, which is semi-urban and not a scenic area. Most noticeably, it’s difficult to do any kind of wider-angle photography without getting houses and wires in the photo. So my winter photography recently has been pretty limited.

Above, a mockingbird realizes some more calories are needed to keep warm, and snacks on some late berries. Birds are a good subject in wintertime, since they remain active but become much easier to spot, and generally stand out well against the snow and bare branches – much better with brighter light than this, though.

But sometimes, you can do something a little different. The clouds were clearing tonight, allowing a few scattered stars to peek through. A long exposure (in this case 20 seconds) can bring up the fainter stars, set against the snow-covered branches illuminated by the streetlights. I chose darker branches for this image to emphasize the stars more, and to allow more of an impression of what you’d see gazing up from a dark locale. Right now I haven’t determined if the constellation Orion is obvious enough to most viewers, or if the three belt stars are more confusing in their symmetry and I should have stayed with just a random star patch.

Journalistic integrity

Al Denelsbeck

I’ve been reading a couple of books recently on photojournalism, one by the editors of Time, the other by the editors of National Geographic, and it’s brought up some things I’ve kicked around in my head for a long time regarding how we think of photojournalism, and most especially editing. Lucky you now gets to read them, if you skip below the break.

Cold weather tips

Al Denelsbeck

Six months ago, I provided some tips for shooting in hot weather, so I think this obligates me, by the unwritten laws of blog topics, to write about cold weather tips now. Just as a matter of amusement, I’ll note that in that linked post from June 30th of this year, I remarked about writing it at the break of a hot spell – which many people know was only the beginning of one of the hottest summers on record throughout much of the US. Superstition would have me keep my mouth shut at this point…

The first tip is obvious enough: dress appropriately. But “appropriate” for photography has some additional factors. You’ll want warm gloves, but the ability to operate camera controls too, so either a pair that gives good fingertip dexterity, or a second thinner pair to wear under the first, so you can whip the heavier gloves off to operate the camera yet still not be bare-handed. Your jacket should also provide two things: adequate coverage for walking, stooping, climbing, and dodging, for getting to those good vantage points and angles that I talked about previously; and enough space inside to warm up the camera, lenses, film, and/or batteries when needed. If you’re the type to use a photography vest, you’ll want to have this on underneath your jacket, because it gives lots of pockets inside the warm and dry shell your jacket provides.

Batteries operate efficiently only in a narrow range of temperatures, and getting cold means they drop off in power delivery drastically – don’t be alarmed, since this comes back when they’re warm again. You should have extra charged batteries anyway, no matter what the shooting conditions, but for cold weather, they should be held close to your body heat. Camera bodies are also not terribly temperature stable, and only a short period out in open air will drop their overall temperature down to rob batteries of power, and make the camera uncomfortable to hold, so the ability to get it inside your jacket can help. Decently padded camera bags will retain some warmth through insulation, but don’t be fooled; this is only as long as the camera remains warm. Once it gets cold, putting it inside the bag does nothing but keep it cold, and in fact, may make the situation worse as you hide the camera away from whatever warming affect the sunlight has. The camera will not produce its own heat to bundle around it, like our bodies do.

Having padded tripod legs provides a serious benefit now, as it gives you something to grab that is not metal that’s been sitting out in cold weather (which reminds me: tempting as it may be, leaving the tripod out in the car means you’ve pre-chilled it to painful levels when you need it.) Many tripods come with padding, and you can buy them from the manufacturers as well, but I just use pipe insulation. It’s cheap and easily replaced when it gets chewed up, and better padding and insulation anyway.

A hat with a good-sized brim helps with blowing snow, dripping meltwater, and provides some protection against the low sun angles of wintertime. But it can also get in the way of operating the camera, so there’s a tradeoff. I still prefer my stiff brims as better protection, but it does mean I shove the hat up higher as I put my eye to the viewfinder. Also, cover your ears. A full-face ski-mask helps with exposed skin during wind-chill conditions, but the opening for mouth and nose can sometimes serve to hold warm, moist air against the camera as you compose your shot, fogging the viewfinder.

Get in the habit of closing your camera bag at all times, since blowing snow and dripping water will get inside easily. Also have plastic bags or camera covers handy to keep it off the camera when you’re set up on the tripod and waiting for the right conditions, and a small towel is always a good thing to carry to dry things off (plus it’s rumored that Bugblatter Beasts are more active in colder weather.)

A curious little tip: think carefully about your shots before you venture ahead, especially when looking at that pristine snowfield – once you’ve dragged your tracks through it, you’ve got a long wait before they’re invisible again. Staying to the edges of fields and treelines keeps the evidence of your presence less likely to be in the middle of your composition, as well as helping you stay hidden when the deer or fox appears in your view.

Sunny days, of course, provide the best conditions for winter shots, giving great color and bright snow, and the lower humidity of wintertime means the skies tend to be more deeply blue. You also have the opportunity to get nice color refraction effects from ice and snow, but be warned: even seeing these in the viewfinder is no guarantee that you’ll capture them in the image, since the closing of the aperture as the shutter opens might cut off the effect. Setting for maximum aperture, as seen in this shot, can help ensure that you catch it, as well as providing nice round ghosts instead of ones shaped like your aperture, hexagonal or octagonal. If you want to know more about this, I’ve explained the effects in detail on this page.

If your car is nearby, park it facing the sun if you can – this will provide the best greenhouse heating within the vehicle and may give you a warm haven for breaks. Setting the camera or batteries on the dash can help restore heat, and you can even start the car and set your wet gloves atop the engine to dry – just remember that they’re there and don’t set them on a dirty surface. And if you have a car charger for your batteries, all the better.

If you’ve been out for any length of time, your camera and lenses will have chilled down, which means taking special care when you enter a warm building. The cold surfaces will attract condensation and fog up seriously, so keep the camera in your bag and the lens caps on until everything warms up. If you need to shoot indoors quickly, pop everything into ziplock bags so they can absorb the heat quickly while not being exposed to humidity.

To top it all off, I finished my instruction page for creating a sun and moon guide for 2011. With a little bit of effort (maybe 15 minutes,) you’ll have a chart that tells you precise rise, set, and transit times for the sun and moon in your area, all year long. This is more useful than you might think, when you’re actually planning your scenic and artistic photos (which is a good idea.) It’s one thing to catch a good sunrise; it’s another to be on location among a great setting to take full advantage of it. Yes, I know your fancy cellphone can do this for you – until you can’t get a signal, and in many of the places I shoot, that’s exactly what happens. Use whatever works for you, but planning can make a world of difference.

Enjoy the holidays!

As close as it gets

Al Denelsbeck

Yep, I’m actually out watching the lunar eclipse progress – or at least, I was. The conditions are deteriorating and I’m both too cold and too tired to stay with it. This is as close as I’m likely to get to live-blogging, by the way. I know that’s disappointing my legions of followers who have been waiting for an update.

In my area, we’ve got thin overcast starting to obscure the details and reducing the light from the moon, making the earthglow of the shadowed portion difficult to capture. It’s cold enough that I can’t remain outside with the digital camera (even if I was so inclined) because the batteries lose their charge in such conditions.

Anyway, I’ll be back shortly with some cold-weather tips and a new addition, my christmas gifts to you. Hopefully, if you’re following the eclipse you’re having better luck than I am – I don’t get too fired up about planning astronomical observations like eclipses and meteor showers anymore, since the weather cooperates only haphazardly. In the meantime, you can check out this animated gif of the last total lunar we had, a few years ago. You’ll notice some exposure variations as we tried to stay on top of the changing light levels, capturing either the shadowed or sunlit side. That was a much better night.

On composition, part six

Al Denelsbeck


Some of the things that create the difference between snapshots and compelling photographs are subtle. Nevertheless, they are extremely good habits to have. In this case, I’m going to talk about position.

Because we live in a three dimensional world, the relation and position of objects within the frame will change depending on how close you are to them, how close they are to each other, your viewing angle, and so on. Decent photographers of any sort know that positioning themselves to put the elements together in a pleasant way is paramount, and sometimes takes some special effort. At top, a small portion of Minnehaha Falls in north Georgia was selected to be viewed from the side, where the elaborate splashing of the water provided the greatest effect. To do this, I had to climb up the edge of the falls on some tricky rock slopes to set the tripod alongside the cascade (one of the reasons I wear both beltpacks for the equipment, which don’t swing around, and footwear that can get wet.) This effort provided a perspective not usually seen in photographs of the falls, shown in an overall view at right – the portion I emphasized is towards the top. Being closer to the rocks and foliage enhanced their sharpness against the softness of the rushing water (this is a time exposure,) and even the foliage behind the falls mimics the lines of the water. The light angle on the wet rocks provided increased contrast and made even the subtle colors of the lichen and leaves stand out.

Always consider your background when composing your shot. The shapes, colors, and details behind your main subject can serve to either enhance or contrast it as needed, but can also be distracting. Bold lines, like the horizon, can serve to cut your subject in two, so it often pays to move the horizon above or below your subject, which is often accomplished by getting your own viewing angle higher or lower, or by moving closer to or further from the subject. The sun and moon can easily be positioned among some kind of foreground detail, or carefully allowed to peek through the foliage, allowing a tiny burst of light to provide an accent point without overwhelming the exposure. Getting close to subjects allows them to become larger, so they can be expanded or shrunk in relation to more distant objects or the background. Crouching down can provide a more imposing subject, letting it loom overhead, and can accentuate or silhouette it against the sky.

So, when you are looking for subjects and compositions, wander around, bob a little, crouch and stretch on tiptoe, climb up on handy surfaces, try to see as many perspectives as you can. Position yourself so that the elements fall together in the frame the way you want them to. At left, the higher perspective placed the indistinct water lily in a counterpoint position in the frame, giving a stronger sense of “setting.” The position also allowed me to get greater detail from the wings of the dragonfly – you’ll notice the black “veins” don’t stand out as well against the dark water as the green leaves. Had I gone for lower, though, I would have been crowding the dragonfly against the flower, too close together in the center of the frame.

Also be aware of the changing nature of your background. The sun and moon move steadily across the sky, sometimes faster than you think (I mentioned before that they move their own width in 150 seconds.) A little patience or planning can sometimes allow you to place them in your frame as needed. Clouds also move a bit, and can fill a spot in an empty sky for greater atmosphere (heh!) or can alternately form a distraction behind your subject. I’ve waited out the clouds more times than I can count – sometimes it simply fails, since they don’t always do what you want them to. But sunlight coming through leaves also shifts quite a lot in a few minutes, perhaps providing you with a nice spotlight as needed, or shifting away distracting hotspots. And the edges of clouds or hazy patches covering the sun can serve to soften the contrast in a scene without changing the color register too much.

Another example seen here was a result of liking the shape of the leaf and wanting it to accentuate the frame, helped by the butterfly facing that way. To get it, I had to balance on one foot while leaning out off of the walkway, trying not to fall into the foliage. Such a simple effort to place the subjects within the frame in a better way; not hard to do, it just takes the effort of trying to see things dynamically.

For the infra-red exposure at right, I was balanced with both feet on one small rock in the middle of the stream, while the tripod was in the streambed itself, pressed downward into the mud until it settled firmly. If you look at the details within the image, shifting left or right by any significant amount would change the relation of the various elements to each other, producing a different composition, one that I found weaker than this one. It might have been even stronger had I been able to get higher, showing more water and more reflection of the sky within it, but sometimes you deal with the limitations.

Were you aware that the sky is the deepest blue facing away from the sun? Can you look at the sun’s position and know where the light will fall earlier or later in the day, so you can return when the light hits your subject more dramatically? Have you noticed that the reflections in the water depend on what angle you’re standing at? How about how different people look when you photograph them from waist or chest level rather than eye level? Now try it with pets – you’re going to have to get real low, and this is often an invitation for nose smudges on your lens, but it makes a world of difference to animal photography. Here’s a hint: a small, inexpensive auto floor mat makes a great ground pad, keeping you from mud and grass stains when working low – knee pads help too, especially in stony areas where it can get really uncomfortable. Here’s another sneaky thing: I’ve taken photos by setting the timer on my camera and extending it well above my head on the tripod or monopod, gaining a perspective I myself couldn’t even see.

Feel free to look around the gallery, and ask yourself where I had to be to get any particular image. If it seems like a lot of them require an angle or perspective that isn’t “normal,” then you know why it’s such a useful thing. Don’t just take the photo – assure yourself that the ones you take are the most effective perspective you can find.

Communicating science

Al Denelsbeck

So in an earlier post I denigrated some efforts that were being taken supposedly to “communicate science,” or to be more specific, to help foster an interest and understanding of science and try to reduce the idea of scientists as either hopeless nerds or conmen pulling a fast one on the public to maintain their funding. Science is quite simply the most functional of all of our survival practices, and the one that fosters nearly all of our advancement as a species. Despite this, it doesn’t have much support in this country, and this is ludicrous. So I’m providing a couple of thoughts and ideas to help spur this along.

First off, though others have covered this themselves, I’ll go into the problems with the “Rock Stars of Science” campaign that has been implemented, where major researchers are posed, bearing their haughty superhero faces, with popular musicians or performers, also wearing their stoic deadpan faces as if waiting for the photographer to finish screwing around so they can get to the serious business of writing their timeless poetry. The reason this fails to promote science is quite simply that it relies on the ridiculous pandering to image that rockstars utilize, while at the same time saying that scientists need a leg up from members of a “community” known for substance-abuse, hedonism, facades, and fame garnered almost as often through outrageous behavior as solid musical accomplishment. Rockstars aren’t really the bottom of the celebrity heap, that position being held entirely by Tom Cruise, but they’re not exactly held in high esteem, either. And it does nothing to actually promote science, because it ignores what science does in favor of seeking the apparent opinions, through association, of figures that aren’t known for their thinking abilities.

This isn’t to say that the rockstars are stupid, any more than anyone else that could have posed for the pics. They’re simply not known for intelligent discourse, but for much shallower and image-conscious traits. That’s almost diametrically opposed to science and its value. Anyone may leap in and provide examples of rockstars that are smart, if they like – I have my own list of rebuttals handy, and you damn well know it’s a good one. Ima let you finish…

Now, if you really wanted a photographic ad campaign, then how about going the real superhero route, posing them (alone!) with their haughty expressions, and then listing their latest escapades:

Andre Geim and Konstantin Novoselov: won Nobel Prize in Physics for their work with Graphene, the thinnest, strongest lattice of carbon. Graphene is a single atom thick yet impervious to penetration by even very small atoms, transparent, an excellent conductor of electricity, and able to bond to numerous materials, promising significant breakthroughs in microcomputing, conductive materials, and bullet-proof tights.

If you like, these photos can be elaborately staged to be even more dramatic, catching the eye while sneaking in the impact of their work. If you really want to promote image and facades, at least do it from an effective standpoint. Hell, I’ve had my own fun simply composing the photos for book reviews, from Demon-Haunted World with its haunting shape in the background darkness (too subtle it seems,) to Why Evolution Works with its family tree, Last Chance To See on its tiny fragile island, and Your Inner Fish dragging itself from the water.

Chris Mooney is one of the big supporters of this program, and his other pet obsession, as a supposed science-promoter, has been to blame scientists for their inability to use proper “framing,” which is to present their work in a manner that makes it acceptable to more people. There are some major problems with this. Recognize that scientists are not promoters at all, and it’s asinine to think that they should be. Promotion requires a fair amount of marketing savvy and a lot of time and effort, not to mention money. Scientists are the people who get the real work done – requiring them to spend any length of time playing around with how to promote their work simply means far less work gets done. And this is accompanied by the fact that their expertise, their entire background, is generally in lab work, study, and research, not in marketing. It’s easy to spend eight to twelve years getting an education just in their own specialties, and now Mooney thinks they should spend more to learn promotion? Not to mention that science budgets are exceptionally lean, and hard to obtain – no funding source is likely to add in some more for advertising, and if they did, it would be to professionals, not researchers. So apparently this promotion is going to come out of the scientists’ own pockets? Consist entirely of press-releases and conferences? I’ve got news for Mooney – that’s already being done. The journalists, of which he claims to be, generally don’t attend, and when they do, they fuck up the story anyway. Thanks for you thoughtful contributions, Chris.

It also needs to be said that many aspects of scientific study and breakthroughs don’t promote well, because the science is so specialized that explaining it to the average person takes a ridiculous amount of time. Analogies, when they can even be used, are fraught with the danger of misrepresenting the science too drastically, and promoting misunderstandings. This is usually compounded by the intentional efforts to misrepresent by those who oppose the scientists’ work, or don’t like the bare facts involved (religious fundamentalists and corporate-funded politicians, I’m looking at you.) And it’s also hampered by a very simple thing: it takes a certain kind of mindset to present things to the public effectively, one that is not taught or encouraged in the degree programs, unless your degree is in education.

That leads in to the next bit. In two review books, Demon-Haunted World and Your Inner Fish, I caught the initial stirrings of this next idea, because both authors touched on it when they related their experiences in classrooms. Young students are often fascinated by new science, and of course, this science must be couched in terms they’ll comprehend. And this is one of the key times to foster an interest in science to begin with. So how about a program where local university researchers are invited to speak to elementary school classrooms on their work, or any related work? This costs nothing, and requires a minimum of prep time. It gets the kids interested in science. It gets the scientists involved in communication, and actively seeing what works and what doesn’t – moreover, in a non-judgmental atmosphere. It lets the kids see the real world applications of new research, and also their own schooling. And it provides the existing teachers with material to springboard from, and discussion topics for at least the next week.

In fact, even grad students could address high school classes as part of their degree programs. This serves an additional purpose of letting the high school students know what awaits them soon afterward, while getting the grad students presenting their work. The rapport from similar age groups may be greater, and overall (for both scientists and grad students,) it presents a distinctive affirmation of their work efforts, recognition that often doesn’t come from presenting at conferences and submitting papers. School age students can be more enthusiastic about the findings, and entertained by the lab stories. Handled well, it’s also a great source of public interest stories that newsrooms are always looking for, and while the typical ten-second soundbite is a pathetic excuse for “news” (as is nearly everything on public access TV,) it’s still better than no exposure at all.

The program might also serve to get colleges and local schools more communicative, which wouldn’t hurt. Such a program shouldn’t be mandatory – there are some researchers who really would make terrible presenters – but it should be encouraged and potentially worth some special credit or recognition. It’s also a program open to private foundation funding.

Speaking of encouragement, consider the amount of time, effort, and funding spent on high school and college sports. Now, think about why: what is it accomplishing? Physical fitness? No, the exclusivity of varsity sports (which is encouraged, and even part of the appeal) rules this out as a decent excuse. So, do they promote students towards better careers, accomplishments, or motivations for the younger students? Only a handful of athletes go on, from any college, to using these skills later on, often for a very brief career if at all. Varsity sports are, quite simply, pandering to instincts, the mistaken belief that competition of this type is functional. In some cases, it gets more funding for the schools, but seriously, aren’t schools about education? Isn’t one of the key interests on college campuses about changing standards? Do schools really have to prostitute themselves and their students just to keep afloat? And if so, when is this going to change, and who’s going to do it?

If academic accomplishments are the prime raison d’être of schools, then they need to be recognizing academic accomplishments at least twice as much as they do sports. Does the math team have school uniforms? Do the winners of the history fairs and spelling bees get something more than a $12 plastic trophy? Do the various science competitions take place as often as the softball and field hockey games? How are the kids going to excel in such pursuits if they have one big buildup per year (if that – my school had nothing of the sort) and then the kids are back to zero in a different class the next year? Do the academic accomplishments make it onto the roadside signs as you enter town? The attitudes about science are developed during these very years – why is it given such short shrift?

Science isn’t a spectator sport, so it’s hard to get kids and parents involved? Then you’re not doing it right. Rocketry is one of the coolest things to watch, and it’s readily available to adolescent kids. Robotics can be used for competitions of all kinds, and it’s far less violent – often it’s even funny. Even basic competitions like spelling bees and trivia eliminations can be made more exciting with the simple addition of countdown buzzers and activity-based styles, rather than simply standing on a stage. We cheer when someone catches a ball simply because we’re conditioned to – we’re surrounded by it. Promoting academic accomplishments requires the same kind of enthusiasm. All it takes is a little creativity – and the motivation that this is important to foster.

What this means is community involvement, enough to get some momentum going. Only a few years ago, the emphasis on adolescent extra-curricular sports programs began, creating the term “soccer mom” and a whole new expectation of what quality time with the kids was supposed to consist of. But parents really don’t participate beyond cheering from the sidelines and supplying the kids with materials and transportation; imagine if they instead worked with their kids on projects, like this one to send a video camera into the stratosphere. How many parents during a parent-teacher conference will it take to get more science-based programs active in a school? It would be a damn sight better than whining about christian “values.” Call me crazy, but I think real education actually has better value.

Should we take money for such endeavors from the school sports programs? Give three reasons why the hell not; provide what the useful functions are of school sports. I’m not talking about mandatory gym classes, which do fulfill a need for physical activity – I’m talking about varsity sports and competitions, programs that need equipment and uniforms and stadiums/fields and transportation. Can you, reading this right now, come up with three things you, or anyone you know, developed during high school and college sports that are used in your current careers? Yes, there’s resistance against cutting school sports programs – there’s resistance against lots of things. That’s not an excuse to avoid them, if there are better choices.

There’s also the possibility, for those creative enough, that academic competitions exist right alongside sports competitions, and serve the same funding purposes – which means increasing the available budget for schools. Can this be done? Of course it can – but it needs community support. If you’re on this blog (and have read this far,) chances are you’re supportive of science. That’s a start, as long as it’s treated like one.

A disturbing aspect of science communication and education is that it’s the parents who are often holding the kids back. Not only by spending so much leisure time on sports, giving the subtle message that they’re much more fun than nature or astronomy programs, but by going to zoos, aquariums, and museums and not being prepared for the questions. It’s an ugly fact: no parent will ever have all of the answers for the questions their kid has. The problem lies in either providing false information in an attempt to look knowledgeable, or in simply dismissing the questions as if they had no merit. Most of this can be solved with a notepad or a voice recorder! Copy down all of the child’s questions, and see that they get answered later on. This even presents opportunities to springboard to new topics or expand on some trivia, something I engage in occasionally with this blog (see the “Too Cool” entries linked on the sidebar.)

It’s not really that we have a problem with science in this country, it’s that we don’t even realize when we’re de-emphasizing it. Our culture has developed around different lines and this isn’t going to move us forward in any way – indeed, we’re dropping steadily behind. The US doesn’t really need to be the world’s source of airheaded media personalities, frothing televangelists, and overpaid steroid junkies. This will only change when we make it change ourselves.

Book Review: Your Inner Fish

Al Denelsbeck

In a previous review, I talked about a book that dealt with the concerted efforts by creationists to discredit evolution, and the book was specific to the goal, but not aimed towards greater familiarization with evolution itself. Enter Your Inner Fish: A Journey into the 3.5-Billion-Year History of the Human Body by Neil Shubin, which tackles that aspect more specifically.

Shubin opens with some background of fossil hunting, leading quickly into the recent find that his team is best known for: Tiktaalik roseae, a species from 375 million years ago that shows critical evidence of the grand migration of animal life from the seas onto land. Tiktaalik was a targeted find, in that Shubin’s team knew that an intermediary stage between finned animals and ones with supporting limbs (tetrapods) should exist, in a particular timeframe, and likely found in areas that used to be estuaries and rivers. After having found a tantalizing fragment in a road cut in Pennsylvania, they approached the problem systematically, searching for geology that would fit all of their criteria, and mounted several expeditions to a remote spot on Ellesmere Island in Nunavut, a Canadian territory. They found exactly what they were looking for, proof of careful planning and the predictive power of evolutionary development, while also relating just what fossil hunting entails, which includes patience, experience, and a meticulous attention to detail.

But Shubin is at heart an educator, which is more than simply a teacher or professor, and Tiktaalik serves as a springboard for much larger topics. Beginning with the appearance of a new limb form that holds for all mammals today, Shubin lays out an exceptionally detailed account of numerous traits within various species, including humans. He gives a great accounting of the scientific method as hunches and suppositions are subjected to careful testing, as well as building on the findings of countless scientists of the past. Through careful explanations with consideration of layman’s terms over scientific, he provides a wealth of information showing the commonality of many species, leading irresistibly to shared ancestry. The reader learns of the difference between not just the appearance, but the functions, of reptile and mammal teeth, and a key point where the two diverged from the ancestors – and how this can be told from the wear pattern on a solitary tooth. Indeed, anatomy plays a key role in determining the functions of fossilized animals we can never hope to see moving on their own, as bone thicknesses and even the shape of skull fragments tell tales about flexibility, diet, and nerve branch similarity to species currently in existence.

There is a fascinating section on embryology, where the initial development of diverse species such as sharks and hominids, of which humans are classed, bear a striking resemblance. While this is an indication of a common ancestor close to 400 million years ago, Shubin ensures that it’s not left at that. He also talks about genes and how they have almost identical functions in many diverse species, and how this was even discovered. In one experiment by researcher Randy Dahns, a gene called Sonic hedgehog (no, really) was grafted onto a specific section of a skate’s embryo during a key period in its development, resulting in the development of rudimentary digits – fingers – in the skate:

Not only did the rods [finger bones] end up looking different from one another, they responded to Sonic hedgehog, much as fingers do, on the basis of how close they were to the Sonic hedgehog bead; the closer rods developed a different shape from the ones farther away. To top matters off, it was the mouse protein that did the job so effectively in the skates.

The whole section details the specific job that genes play in embryological development, even down to the shape and position of “thumbs,” and most especially how those genes work exactly the same even when transplanted into diverse species. The body plans of nearly all species on the planet use many of the same exact genes to get started. Shubin also returns several times to the enigmatic bones of mammalian ears, which have ancestry in a wide variety of skeletal forms and developed gradually from jaw and skull structures to specialized instruments for wide-frequency hearing, for those species that would most benefit from such.

While the book is certainly not adequate to explain all that we know about evolution, and indeed doesn’t actually talk about the mechanisms of selection, it is overwhelming when presenting the evidence that this has indeed taken place. The reader who comes away from this book unconvinced is only guilty of abject denial. Other readers, without a distinct background in biology, might actually be startled at the number of factors that Shubin relates, tying us together with our distant aquatic ancestors (and further) in appropriate recognition of the title. One missing facet that I would have liked to have seen addressed, personally, is the predictive power of this knowledge, and how it applies to modern medicine and biology to show that it is not merely historical background, but functioning and active science. While this may have been outside of Shubin’s expertise, it would have been a powerful addition to the book.

Because of the amount of information, I wouldn’t recommend this book for adolescent or young-adult readers overall; while adequately illustrated, the text is just a little dense, reflective of the meticulous way that scientific progress is made. This is not to say that the book is hard to read – Shubin couches things in everyday terms, and avoids using scientific jargon where it is unnecessary. At the same time, he provides the subtle message of how science progresses, including the background stories of our previous, now-abandoned theories and how new findings changed them. Besides the evidence for evolution, the reader also receives some indication of how we establish and correct our knowledge base, and how much of this has happened in the past century. We are in a golden age of discovery, and it’s fascinating.

Shubin also touches on a constant mistake of the media, that of referring to fossil species as “links,” missing or otherwise. The fossil record provides only pinpricks of life from any given period, and species do not cleanly develop in a line, but branch off, spread out, and often die off. Tiktaalik, then, might be a direct ancestor, but the probability is exceptionally low. It is instead evidence of species developing a new body plan that allowed life on land to develop, and may simply be one of dozens or hundreds of species that came ashore over a period of thousands to millions of years. That’s part of what the genetic record supports: so many species have such similar backgrounds that the development of weight-supporting limbs, for instance, might have taken place several times due to the same genetic changes, or small variations thereof. It’s a bit as if human descendants in the future, with no knowledge of what we are like now, found chimpanzee, gorilla, orang-utan, and human remains – only one leads to those descendants, but all have much the same structure.

Much of the charm of this book is the ability, within every chapter, to make the reader blink and say, “That’s cool!” It is an excellent example of why science should be more popular in this country, and why it’s so useful. But it’s not simply about popularizing science; it also shows the painstaking research and careful experiments that go into it, and pays homage to the countless people who have contributed, in large or small increments, to what we know today. The reader comes out of it with a wealth of understanding, and a newfound respect for the process and practitioners. Definitely worth the time – it’s a very memorable book.

* * *

No, I did not abuse the book for the illustrating image – this is simply the wonders of Photoshop.

Compensation: It doesn’t refer to those giant lenses

Al Denelsbeck

After a recent post, someone remarked about the effect I showed in one of the illustrating photos, reminding me that this is one of those photography techniques that’s much easier to implement than to explain – and I know, because it’s the hardest thing I’ve had to teach students. So here goes an attempt within a post, on the subject of exposure compensation.

One key part of decent photographs is having the proper amount of light reach the film or digital sensor. It’s called exposure, and it’s controlled by three things: the shutter speed, the aperture opening within the lens, and the sensitivity of the film/sensor to light, as indicated by the ISO. Today’s automatic cameras have some pretty sophisticated ways of measuring exposure, but there’s still one consideration the photographer has to make, and this is that the camera has no idea what it’s looking at – it simply measures light coming into the camera. If you break down the majority of photographs, you’ll get an average of light reflectivity from them, which unsurprisingly is a middle tone – we are surrounded by subjects that reflect light in moderate levels rather than extremes. Grass and foliage, clothes and buildings and cars, painted rooms and the various bits of furniture and knickknacks within, all have a tendency to be not too bright and not too dark. Mind you, I did say tendency, and in many cases where there are greater extremes, these can balance one another out. The upshot of all this is, even when the light is very bright (outdoors on a sunny day) or very dim (under streetlights at night,) you still tend to have an average middle tone when properly exposed, so when the light comes in to the meter, the camera sets the exposure to bring this light to a medium level. This is usually referred to as “18% grey,” and you can even get pieces of cardboard colored like this to help set exposure in crucial circumstances. If it helps, picture a grey shirt under direct sunlight and under streetlights. Even though the light levels are drastically different, the shirt is still grey and should appear that way in both photos.

A small side note: most meters don’t read colors and only measure light intensity – it really doesn’t matter what color the light is, only how bright it is. Nikon is one exception, with some of their higher-end models, but I honestly don’t know how significant a difference this makes. Suffice to say that I have heard no one enthusing about the advantages, and I have never cursed not having color sensitivity in the meters of my Canons.

So, when the light comes pouring into your camera before you actually snap the photo, the camera measures it and sets exposure to render it into a nice middle tone. The problems arise when the subject is not a nice middle tone. Such examples are snow, sand and water, surrounding sky, and white walls for the brighter side, and commensurately night skies or background darkness, dark wood paneling, and deep shadow for the darker side. We expect all of these to be either bright or dark, but the camera usually doesn’t know this (some metering systems are fairly clever in comparing the focused point within the frame against the surrounding area and figuring exposure for your focused subject, but they’re still fooled sometimes.) So the camera goes for the mid-tones, and either darkens your snow and sky too much and makes them grey, or brightens your wood paneling and distant unlit backgrounds too much and bleaches out your subject.

I used to work in a photo lab, and the two most common circumstances that virtually always wrecked exposure were kids in the bathtub, and the prom/formal dance shots. Bathrooms are usually pale and reflective, with few items of a darker nature, so the camera rendered these too dark, not knowing they were supposed to be bright. And of course dances, with no light from the background and even the subjects dressed in tuxedos and darker dresses, are supposed to be mostly dark, but the camera tried to make it brighter, generally blowing out the happy couple’s faces into over-exposure. Consider also how bright the sky usually is, so birds (often a tiny subject) against the bright sky usually end up silhouetted against an expanse of grey or deeper blue.

Enter the thinking photographer. “Aha!” says he or she, “this scene is brighter than average, and it should be! So I have to outthink the camera and foil its evil plot!” Or something to that effect, anyway – you may not be as dramatic as I am. Faced with a bright scene, the photographer sets exposure compensation, purposefully telling the camera to over-expose the scene. It’s not really over exposing, it’s actually obtaining the correct exposure, but we’re dealing with a simple microchip here that doesn’t know snow from grass. So you correct its mistake.

How? Well, it varies by camera, so there isn’t a simple answer, other than to find out how to do this in the manual. Most of the SLRs, digital or film, usually have a wheel that you can adjust after getting an initial exposure reading (often by half-pressing the shutter button) to change exposure, and this is indicated in the viewfinder and/or in the LCD window. See a bar with a ‘plus’ at one end and a ‘minus’ at the other? That’s your exposure compensation indicator – simply move the pointer towards the plus end for over-exposing (bright scenes) or the other way for t’other. Other cameras may have you do this with the menu buttons on the back, and this option is usually represented with a “+/-” symbol of some kind. Hold this down and spin your wheel or push your rocker switch, and watch for the same change in the LCD indicated above.

This is 2/3 stop overexposed, leaving some texture in the snow but still making it bright - note the pure white highlights
How much? This is even harder, because it depends on the scene. Snow in bright sunlight, for instance, usually requires anywhere from 2/3 of a stop to 2 full stops to look properly bright, if there’s a lot of it in the scene. Beach scenes a bit less, maybe 1/2 to 1+1/2 stops over. Objects against bright sky? To keep sky color, usually 1/2 to 1 full stop. The prom? Usually 1/2 to 1 full stop darker – you might be surprised how much a tuxedo reflects. If you’re wondering what “stop” means in photography, I have a new page about it here.

If you’re using digital, you can afford to waste shots, so try several variations. This is called “bracketing,” where you adjust exposure from the camera’s recommendation and often go on either side of the guessed exposure, three to five separate images – one of them will usually get it right. By the way, tell your subjects you’re going to do this, lest they relax after the first one and the next few frames have weird faces in them. Also, be sure to wait for the flash to recharge if needed.

There is another technique that can work, too. Many cameras have the ability to lock exposure, meaning you get an initial meter reading and then retain this when you re-aim the camera. Sometimes this is linked to keeping the shutter release half-pressed, other times you may have to do this with an additional button often marked with “*” [asterisk.] To use this, you aim away from your bright or dark scene to something else that is average, and obtain and lock your meter reading there – the best example for this is capturing the sunset, where you can aim down at the ground without sky in the picture, lock that exposure, then tip the camera back up and snap that shot. Often you don’t have to point all the way down, simply get less of the sky in the image. Sunsets usually benefit from being darkened, since it makes the colors richer, but they still should be fairly bright. It takes practice, so experiment. But this technique is often the quickest, and can be done with less fiddling on some cameras.

Finally, always, always, always be aware that you just changed your camera settings for a special circumstance, and change them back when you have the shot. The large number of frames you shoot the next day will probably be better without the compensation. Coupled to this is the practice of always, always, always reviewing what the camera is set for the moment you take it out. It’s easy to get caught on this, so make it a constant habit. It’s better to remember to reset the camera to average settings before you put it away, so it’s ready to be whipped out when the UFO goes past or the skateboarder hits himself in the goolies. And if you get in the habit of both (checking when you put the camera away and when you take it out, I mean, not something weird with alien genitals,) you’re doubly ensured that you’re not taking images with exposure compensation in place when you don’t want it.

Another example can be seen here. Both the bird and the sky were very bright. While I wanted the bird to look white, I didn’t want to bleach the feather detail away into pure white, so I only compensated by about 2/3 stop over what the meter suggested. Note that the top of the bird’s head and the throat have lost detail, but only in small areas, while the underside of the bird has gone almost completely black – the hazard of using high-contrast slide film in bright light. If this had been a black bird and I didn’t compensate for the background sky, I would have lost all detail from the feathers. It takes experience to know what situations call for it, and how your camera will react (especially in different metering modes,) so practice!

1 … 276 277 278 279 280 … 292