As I was taking my oat grass guttation pictures, I kept an eye out for cute critters on my newly planted grass. And, of course, there were some:
That’s a young family of aphids, just starting out in life. Aphids are phloem-feeding plant parasites, so they’re sittin’ there having lunch. They have a proboscis they insert into the leaf’s phloem vessels, which they then drink like a soda through a straw. Phloem is just about as nutritious as soda, so aphids have serious problems getting enough nutrition and dealing with the sugar overload, but that’s the topic for another post (and probably another blog …).
The larger aphid is almost certainly a parthenogentically reproducing female. She reproduces asexually, creating more daughter offspring from just her own unfertilized eggs. Yes, kids, that does mean that she can have baby aphids without any daddy aphids around.
So, the six smaller aphids (called nymphs until they mature) are almost certainly her offspring. The mother will keep producing more and more offspring asexually, and these offspring themselves will almost certainly be able to parthenogentically reproduce as well1. That grass stalk won’t be happy for long.
It can often be hard to tell from web-sized images how much detail is contained in the original capture. Since I know you’re thinking that these aphids are adorably cute, here’s a crop of the image above focusing on them (see the same crop as a larger image here):
I’m not certain what species these aphids are, but I suspect they may be Diuraphis noxia, the Russian Wheat Aphid.
Oh, and the small drop of water at the tip of the grass stalk is there because the grass is guttating – exuding water from its tip due to root pressure. I write about that more in this post.
1 Winged and/or sexually reproducing individuals can also be born, typically when environmental conditions change dramatically (e.g., the onset of winter, or depletion of the food source).
I personally donate to the Humane Society, and am happy to help a good cause. As such, in addition to entering my images into their judged category, I’ve also entered them into their “fundraiser” competition. In this competition the entries compete for votes, which can be obtained by donating to the Humane Society:
“Kira”
“Lucca”
There’s no way I can win the fundraiser category, and I don’t want to try1. Instead, I want to use this as an opportunity to give you an excuse to donate a little something to a worthy cause. And, just to reinforce the idea that I’m not in this for the fundraiser competition prize, if I do somehow win I’ll donate the prize (an iPad 2 and iPod) to the Orange Coast College Disabled Students Center.
The contest ends February 29 at 10:00pm EST, so donate before then if you desire (by following the links above).
1 Votes are tallied per individual picture, not per photographer. So, by posting two pictures I’m possibly splitting any votes I get. But this way you get to vote for your favorite of my two cats!
Last weekend I got a few more pictures of my cats, this time focusing on the eye (as opposed to the tongue or third eyelid). Lucca was a great model with her beautiful green eyes and blue patched tabby and white fur:
The first one makes a great desktop background (and no, I’m not biased at all …); in fact, I can see Lucca’s nose and whiskers poking out just to the right of the window I’m writing this in 🙂
My cats love to nibble on grass, and so I grow tack oats (Avena sativa) from seed for them. About six months ago I figured out that on cool, humid mornings the grass could be seen guttating. At the time I lacked my macro lens, and so did the best I could and got this image. It’s an okay image, but I don’t like the choice of background in retrospect, and I also wanted to get in closer and show just a few stalks of grass so the water drops would be more obvious.
Over the weekend some newly planted grass was again demonstrating guttation, so I tried anew:
Guttation is caused by root pressure building up so that water is squeezed out pores (hydathodes) at the tips or sides of a plant’s leaves. It typically happens at night, under cool, moist conditions when the soil is well hydrated. As Wikipedia says, it’s important to note that guttation and dew are two completely separate phenomena.
To demonstrate guttation in a typical botany science lab , a technician sets up a few-weeks-old pot of grass under a bell jar, waters it thoroughly, and leaves it for the night. The next morning tiny drops of water cover the plant’s leaves. One thing I like about my example is that it’s free of lab manipulation: this pot of grass was just sitting on my porch when I saw the guttation and brought it in to photograph.
If you’re curious how I photographed these, I used a technique much like1 that used with my poinsettia flower closeups; see my behind the scenes post for more details.
1 The first image is a single-frame capture; the second is a multi-image blend to increase depth of field. Both use a studio setup almost identical to the poinsettia setup, except I used reflected direct sunlight to aid in illumination.
Last month I spent a few days in New York City visiting family. One afternoon we walked over a bridge. You may have even heard of it. Apparently it’s called “Brooklyn Bridge”.
You have heard of it? Huh. Surprising.
So, yeah, we walked over the Brooklyn Bridge. And I had my camera with me. You know what’s coming.
The Brooklyn Bridge seems like one of those places like Half Dome: it’s been photographed by every photographer who’s come close to it since silver was capturing photons. I figure that by now every angle from every position in every lighting condition at every time of the day has been photographed (at least from the pedestrian walkway). So, when we decided to walk over the bridge I wasn’t super excited about getting lots of pictures. I figured I might take a few “I was there” shots, but that’s it. After all, we were on our way to Murrays’ to get cheese.
We got on the bridge, and I was blown away. It’s full of contrasts: stone and steel, cables and ties, pedestrians and cars, water and sky, clouds and sun. And I’ve never seen so many leading lines in a single location. My heart went aflutter.
Let’s just say that I took a “few” pictures, and leave it at that.
It was a blustery winter day, and as I walked the bridge I was awed by its age and grandeur that was mixed with city grit and grime. I tried to capture that feel with some high-contrast black and white processing in this image (which looks better viewed larger on my gallery website’s page for it):
The flags on top of the towers were blowing beautifully in the wind for most of the walk, making me have to play with the cables as leading lines on a cloudy, gray background.
But as with the bridge, the day was full of contrasts. As we continued walking the setting sun broke through the clouds for a precious few moments to cast a brilliant orange glow on the cables and brickwork, as the Financial District and the new 1 World Trade Center rose in the background:
I’m happy I was one of dozens of folks with DSLR’s on its pedestrian walkway that day. Oh yeah, and we did get to Murrays’ in time to pick up some good cheese.
New feature alert: I’ve always enjoyed reading other photographers’ “behind the scenes” and tutorial posts, so from now on I’ll occasionally post them. This post focuses on the “studio” and exposure blending techniques I used to create a macro image of a poinsettia flower.
Introduction
Last month I wrapped up a three-post series on poinsettias (post 1, post 2, and post 3). The images for the first two of these posts were taken back in December in an Orange Coast College Ornamental Horticulture greenhouse, which was a great location to work in as it had slightly directed diffuse light (sun shining through semi-opaque panels at the top of the house) and hundreds of plants to hunt through for specimens. Unfortunately, though, poinsettias have separate male and female flowers, and only the male flowers were visible during that shoot.
Thus I had to keep a plant at home and wait. About a month later the female flowers had emerged, and I was able to get some images and finish the series. The highlight of the series (for me) is this closeup on an inflorescence that demonstrates all of a poinsettia flower’s anatomy in a single image.
The image:
Lighting, equipment, and setup
Getting the shot was not trivial. First, I didn’t have access to the greenhouse, but needed to get similar lighting to maintain consistency between the images in the series. I found good lighting in a room of my house that faces east, and has white curtains and bright walls. In the early morning the sun hits the curtains and diffuses through the room nicely (while maintaing some directionality to the light).
I used my Canon 60mm ef-s macro lens in manual-focus mode, and determined the base exposure and set a custom white balance in-camera using a gray card (see this post by Greg Basco for why setting a custom in-camera white balance is useful). Said gray card was photographed out of focus, so it also served as a test for dust spots (which can be deadly during exposure blending for depth of field).
I’m tired of taking macro photographs with my camera hanging down from the tripod, so I supported the plant on a chair a few feet from the window, with my camera in between the window and plant. This allowed me to move either the plant, tripod, or tripod head to adjust framing.
Framing closeups of plants is tedious, as leaves and other structures often get in the way and cover up important anatomy. I put some leaves underneath the lens to corral them, but a few others kept popping up annoyingly. My solution was to weigh them down with my lens cap. High tech, I know.
The background was another issue. It was clearly going to be out of focus, but I needed the color to not be glaring. For the first two shoots in the greenhouse I simply grabbed an additional poinsettia or two and put them behind the first plant. Voila! Instant matching background.
For this shoot my first background was a white closet door. The white became a bit jarring for the composition above, though, as there were just a few white spots shining through the red bracts. So, I grabbed a black shirt and hung it on a chair behind the plant. The background disappears, and you probably didn’t even know there was a black background behind the bracts (which is exactly what I wanted).
Here’s a picture of the setup:
Settings and image capture
Next came the old debate of settings. I wanted sharpness and depth of field, and didn’t care a whit about exposure time thanks to being indoors and able to turn off the wind (read: turn off the heater). I’ve found that the lens is sharpest around f5.6 – f8, but at the focal distance I wanted to use my depth of field at that aperture is miniscule. For the first images of the day I was able to get everything I wanted in focus composed in a single plane, and thus I pushed the aperture to f11 and f13 for a bit more depth of field in a single image with acceptable sharpness.
But for the image above I needed more depth of field, thanks to that giant ovary and large cluster of male flowers. Thus, I fell back on my old standby: image blending for depth of field. Greg Russell has a great tutorial on image blending which summarizes the technique beautifully.
The technique I used boils down to this: I started by setting the focus and exposure to manual and focusing on the closest subject I wanted sharp (the pollen grains on the front of the ovary). I then took a series of images at f8, adjusting the focus backwards by as small a margin as I possibly could as I focused through the range I wanted sharp. Using a macro-rail tripod head to change the camera’s position as I changed focus would have been ideal (since the field of view of the lens changes as it focuses), but as I lack a rail slider I couldn’t do that.
As a side note, assuming that you don’t have a rail slider, always compose your exposure-blended images at the closest focus you plan to use. That’s the focus with the narrowest field of view, and thus the one that will most likely limit your cropping post-exposure-blend.
Processing
I then imported all the RAW images into Lightroom 3.6 and did my typical adjustments (white balance, exposure, black point, brightness, contrast, saturation, noise reduction, spot removal, etc.). I shot a series of 11 sequential focal planes on this particular composition, but ended up choosing only the first eight to use for the final product, as the last three put distracting elements of the flower into sharp focus. I know some people who exposure blend try to get everything in focus (creating infinite depth of field), but I often find this to be distracting; having the background and foreground out of focus provides depth to the image (and also isolates the subject).
Here are the eight processed images that form the base of the final image:
Exposure blending
I used Lightroom’s “Edit in Photoshop as layers” feature to get the adjusted images into Photoshop CS5, aligned the layers using Photoshop’s built in tool (Edit / Auto-Align layers), and then blended the layers for depth of field (also using Photoshop’s built in tool: Edit / Auto-Blend layers).
Exposure blending rarely works perfectly on the first try, though, so I looked through the blended image at 100% to check for errors. Sure enough, there were a bunch: a few “points of light” where photoshop puts a bright spot into the image near the edge, and also a few areas where Photoshop chose the wrong layer to use (thus adding an out-of-focus area into an area that should have been in-focus). Here’s what two of them looked like:
On the left Photoshop has selected a line of the plant stem at the correct focus, but then used incorrect focal planes for the remainder of the stem (both above and below the in-focus portions). A single image has everything from the in-focus portion up perfectly in focus; Photoshop has just chosen … poorly. On the right Photoshop has added what I call “points” or “bars” of light, blending errors (often near the edge of an image) where Photoshop inexplicably adds in a bright streak or point.
To fix these I un-did the blending, found the incorrect layers Photoshop had used, and erased the parts of those images Photoshop had selected. Then I re-blended the image, checked again, and continued this until I got an image I was satisfied with.
Scale bar
To add the scale bar I captured a separate image with a ruler in the frame next to the flower (after I had finished shooting, since putting the ruler in the frame could easily damage the flower), then copied that image as a layer onto the final blended image and made sure the flower was precisely the same size in the ruler image as in the blended one. A quick use of the line tool got me a subtle scale bar that I could move wherever I wanted in the blended image. I chose to put it in the shadows near the bottom, so it’s visible, but you have to look to find it.
Final notes
And that’s it; head back to the top of the post to see the final product!
Using this layer blending technique is a bit cumbersome, but it allows me to maintain optimum image sharpness while precisely controlling the depth of field (by choosing how many focal planes to blend together into the final image). It’s worth doing, but only for those images that really need it.
Thanks for reading! I’d love any suggestions, and would be happy to answer any questions.
In addition to the pelicans Greg and I found in La Jolla last week (see post 1 and post 2), there were also a lot of western gulls (Larus occidentalis) on the cliffs. While the pelicans are a bit showier, I think the gulls are every bit as gorgeous:
With the gulls I also wanted to try something a bit more landscape-ish, putting them in context with the sloping oceanside cliffs leading to a sea of blue. I’m happiest with this attempt:
After our morning with the birds we photographed seals and lighthouses, but those pictures will have to wait for another post.
La Jolla Cove Cliffs: This location doesn’t have an official name as far as I can tell, but it’s accessed from a small parking lot on the right side of Coast Blvd. in La Jolla (San Diego, CA), just after Coast Blvd. branches off from Prospect Place. The best I can do for you is give you GPS coordinates: N 32.84936 W 117.27038. Parking at the location is highly limited (and has a 2-hour max during the day), but it’s a short walk from other parking areas in La Jolla and the lot was virtually empty when I got there half an hour before sunrise on a weekday. The cliffs are accessed from a stairway that descends from the parking lot; be careful to stay well back from the edge, as the cliffs are steep and venturing too far forward will scare the birds away and prevent them from landing.
Last week I headed to La Jolla with Greg to photograph pelicans. In my previous post I shared my highlights from the day, but most of those shots were of calm, sedate birds. There was also a lot of action and anatomy on display:
In that image the third eyelid (palpebra tertia or nictitating membrane) of the pelican is in the middle of a blink, half-covering the eye (click on the image to see it somewhat larger). In birds the third eyelid is under more conscious control of the animal, and is often visible (and is reportedly used to protect the eyes of marine birds while diving, for instance).
And who could resist a bird just about to jump in the air and fly:
One of the distinguishing features of pelicans is their large bill pouch (gular sac) that they use to capture and carry food in. While grooming themselves they will sometimes move their bills in such a way that they invert their gular sac (so the inside is visible), as in this image:
Oddly, in some of my images of inverted gular sacs (see, for instance, this image) there appears to be some type of gland or organ at the base of it. I have no idea what it is.
For a last photo of pelicans, who can resist a picture of a photographer taking a picture of a pelican?
Oh, and I was also asked by e-mail whether my pelican images were heavily cropped. Most of these images are essentially full-frame captures, with just a bit of rotation or cosmetic trimming; they should easily be able to print up to 16×24″ or even possibly 20×30″. The location Greg took me to was just amazing; we could literally get just a few yards from the birds.
I’d appreciate any and all comments on these pictures.
La Jolla Cove Cliffs: This location doesn’t have an official name as far as I can tell, but it’s accessed from a small parking lot on the right side of Coast Blvd. in La Jolla (San Diego, CA), just after Coast Blvd. branches off from Prospect Place. The best I can do for you is give you GPS coordinates: N32.84936 W117.27038. Parking at the location is highly limited (and has a 2-hour max during the day), but it’s a short walk from other parking areas in La Jolla and the lot was virtually empty when I got there half an hour before sunrise on a weekday. The cliffs are accessed from a stairway that descends from the parking lot; be careful to stay well back from the edge, as the cliffs are steep and venturing too far forward will scare the birds away and prevent them from landing.