Polarizing

Polarizing filters are used routinely in landscape photography. There are many examples of how much they can contribute to a scene, by removing reflections, intensifying colors, and darkening skies.
Light coming from the sun is vibrating in multiple directions. The filter basically blocks light in one direction, allowing parallel beams of light to get through in the other direction. This is called "polarization by transmission," and is described further here: http://www.physicsclassroom.com/class/light/u12l1e.cfm
To complicate matters, light is actually polarized by reflecting off water, and the interaction of the two kinds of polarization can be interesting. By rotating the circular polarizing filter, one can see the different effects of the light altering characteristics of the filter in any given direction. Some of the most dramatic variations can be seen by rotating the filter while pointing the camera at a rainbow. It can become much more intense or almost invisible. Here, we're again dealing with light polarized by more than one factor.

Sometimes, the polarizing effects can negate some of the benefit of the scene.
Example: After a long hot hike to a mountain lake, facing about 90  degrees from the sun, I might assume that a polarized photo is the one I want, particularly if I'm wearing my own polarizing filters in the form of sunglasses when I make that decision.
One problem with that thought is that it is usually wise to consider all options when making a landscape composition. The view isn't likely to fly away after all.
Here's the photo without a polarizing filter:

and with the filter:

The critical difference here is the lack of reflections of the partially snow-covered mountains and the trees in the water, making a photo that has much less impact. Same location, camera and lens.

Is Memory Cheap?

There is a lot of talk among photographers that "memory is cheap," referring to the ever decreasing cost   of memory cards and hard drives. The thought being, since memory is so cheap, photograph anything and everything and keep it forever. Sometimes we find that a long overlooked photo is really good, and, years later, uncover its true potential. OK. That happens. But, much more commonly, good photos never get discovered in the morass of all those unedited files kept because we made too many photos in the first place and then didn't delete them when we had the time and energy.
Memory may be cheap, but our creativity isn't. For me, choosing to work on a few really good photos is much more likely to happen if they aren't buried in hundreds that should have been deleted months or years ago. If I cannot bring myself to search through thousands of files to find what inspires me to move ahead, then I'm seriously impeding my own progress.
There are limits to how messy a desk can be before we just give up trying to find anything. Even well organized piles become obstructive when they get too high. Same with photos. I am much more productive when I can look through a few good images to find the one that I want to process than when I try to plow through hundreds. I just lose the motivation. Motivation and creativity are not cheap. To me, that's what matters.

Thoughts on Photographing Wildlife

Much has been written already, and I’m not sure I can add greatly to points previously made about certain approaches to wildlife. Unbelievably dramatic photos of action are so striking, it’s certainly hard to argue against impact. There are good points on both sides of the argument for using captive animals as subjects, and in between the whole captive vs wild discussion, and then there’s the baiting issue. It’s much easier to get exactly what you want when you arrange for the raptor to come to you.

My perspective on these matters may change with time, but so far, the more I contemplate the options, the more I look at what gives me personal satisfaction and meaning as I photograph. For me, even if all the other issues were equal, I believe I would still find more delight in being out there in the moment with the wildlife and just being privileged to witness what they will show me of their world. I am not naïve enough to believe that I can be there and have no effect on the animal I’m watching, but I do think there are ways to observe relatively unobtrusively, and in that observation, I get the spontaneity of not directing my “model,” but of being allowed to see what I have never seen and couldn’t precisely have predicted.

For me, the experience is maybe more valuable than the product. I love the product, but I really love the experience. Great work is done in all sorts of studios, but my best pleasure comes from being in as close to the natural environment as possible, even if that means hours and days and weeks and months of less than I’d hoped in terms of the finished photos. This is a choice of style of work, and it seems to fit my style. It’s not the best choice for everybody, and just maybe, it won’t always be the best choice for me, but it is for now.

Here's a bird who flew by as I was observing other snowy owls in their winter location in Ocean Shores, Washington:

Here's a scene that I had visualized for months before I actually captured it with my camera. It took multiple trips and hours of waiting, but I learned so much about osprey behavior by waiting for those moments:

I watched the bird on the right from days after hatching to seeing it fight with it's nest mates over food and space. Minutes before this photo was made, it had tumbled out of the nest in a struggle with a seemingly stronger sibling, only to recover and get back at the moment dinner arrived.

In each case, I was allowed to observe the birds in as close to their natural habitat as possible. Coming to a better understanding of their behavior, to me, is more fun than setting up the exact shot I want.

Depth of Field: There will be math.


Most of us learned that one increases depth of field in a photograph by stopping down, which is the same thing as increasing the aperture of a lens. (This is one, but not the only bit of confusing terminology in photography.) That's the simple part. Actual depth of field is a function of the focal length of a lens and the lens diameter.

Focal length? Focal length is all about converging light on the plane of "film," or usually sensor. To simplify, focal length is the distance from the optical center of the lens to the point on the sensor where that light converges. If one thinks of the light from a given scene shaping into a pyramid as it converges in the aperture of the lens, and then is projected onto a sensor, it's not too hard to visualize that a long lens will narrow the field of view (the amount seen of the scene). Long focal length = narrow field of view.
For example, a 500mm lens will have a field of view that is tiny compared to a 20mm lens. That's why the 20mm is called a "wide angle lens." That angle is the field of view.

Lens diameter above really refers to the diameter of the "pupil" through which light passes. F8 in a 25mm lens produces a pupil that is much smaller than that produced by a 500mm lens at f8. The trick is that both of the f8 settings will result in the same light on the sensor. That's because in the long lens  that light travels far longer than in the short lens, and with that travel, the light's intensity decreases (actually, it decreases by the square of the distance). The light is the same as far as the sensor is concerned. The fields of view are much different.

Which brings us back to depth of field...depth of field is proportional to the aperture (f stop), the subject distance², the circle of confusion and inversely proportional to the focal length². Circle of confusion? Circle of confusion refers to the size of the sharp area projected on each pixel, or the largest blurred area that we can still see as sharp. Why is the sharp part called confusion? We're now getting back to at least the early 1800's, and it just may not be worth going there for this discussion.
What is worth considering is that for any given focal length, the smaller the aperture (the larger the f #), the greater the depth of field. The farther away the subject of focus, the larger the depth of field. The longer the focal length, there is a major decrease in depth of field (as the denominator above is squared).

So, from a practical standpoint, if I want the greatest depth of field, I use the widest angle lens available, and I focus on something that is not close to me. OK, that sounds simple enough, but it is not quite that simple. How could anything that involves a circle of confusion be simple?
Older lenses came with depth of field scales on their barrels, but this isn't the case with newer lenses made for digital cameras. Many DOF charts are available online, as are calculators, but the easiest approach may be to download an app that is a DOF calculator (simpleDOF is even free).

Here, the focal length was 25, f16, focus was on the leaves in the middle bunch of flowers. When examined at the pixel level, the rock in the foreground is tack sharp, as are the mountains in the background.

There is one more thing. Diffraction. Too much effort towards maximum depth of field, can lead to blurry images. This will be discussed as it's own topic in the near future. Nikon discusses it here for the new D800: http://www.nikonusa.com/en_US/o/Y6wrkA9OU_z04IreazIXl_22UII/PDF/D800_TechnicalGuide_En.pdf

Nikon D800 Camera: exploring the limits of ISO


No question the files from the D800 are great at low ISO's, but I haven't had too much chance to explore just high far I can go with pushing the low light limits. Photographing in overcast conditions with Auto ISO and a teleconverter, the lens combination was stopped down to 6.3. My shutter speed of 1000 resulted in an ISO of 2800. I have certainly produced good files on the D700 to ISO of 2000, and at times to 3200, but this camera with its increased pixel density?
Here is a major crop of a photo of a western tanager male done at those settings:

I did a a little noise reduction only in Lightroom 4 (using Luminance=18, detail=94, contrast=60, and leaving the color noise reduction at default). I don't yet know what the limit is. I don't think I'll have that until I have more full-frame shots at high ISO, but right now, I'm thinking I can be close to matching the D700 high ISO performance, and that is far better than I would have thought.

Camas Prairie


Overcast or rainy days are my favorite for photography, giving the most freedom of time. One can be on the edge of the ever-changing light for hours at a time. The harsh sunlight is not a concern.
Yesterday seemed to offer promise, and I had been anxious to photograph the canola fields in full bloom. So, off I drove into the rainy morning, following a lead from my friends who had reported good fields near Grangeville.

                               Nikon D800, ISO 200, F 8, 1/250 (handheld, as I had to climb a bit to get here)                               

No one was around, this being Tuesday following the Memorial Day weekend, and the countryside was showing spring in greens and yellows and emerging blue lupines. Perfect day for photography.

                                            Nikon D800, ISO 100, F8, 1/100 on tripod

Later, I checked out a place I'd heard of but never visited, Tolo Lake, a small obscure spot that several species of birds seemed to love. I was delighted to find Eared Grebes happily feeding there.

    Nikon D800, 700mm (500 + 1.4 TC),  ISO 1000, F 6.3,  1/640, exposed manually This is close to
    a 100% crop of the image, as the grebes were quite a ways from me.
This is a place I would like to revisit to see if I can get closer to the birds and to try to photograph harriers hunting in the nearby fields.

Equipment report: Nikon D800

I received a new Nikon D800 from Levines (http://www.eplevine.com/, but don't rely on their website. Call them. They're great.) at the end of April. Since that time, I've mostly resisted the paranoia that is associated in the forums at the release of most new high-end equipment. I've just used the camera.

The decision was a bit of  a struggle in itself, as I was torn between the D4 and its 10 fps and amazing low-light capabilities and hoping for a camera that would actually fit in my small hands. As a wildlife photographer, it's not like I don't have enough to carry with a 500mm lens, teleconverters, and associated gear. The other concern was a seemingly in-bred belief that a camera with that many megapixels could not possibly have good low light capabilities. The edges of the day always seem to present the best photographic possibilites, a fact so well illustrated when I spent a blissful morning in the pouring rain at Damon Point in Ocean Shores, WA photographing snowy owls :

                                Nikon D700, 700mm (500+1.4TC), ISO 1600, f5.6, 1/180sec


At the same time, as Nikon was not providing an 800mm lens that I'd been admiring on the Canon front for the past few years. So, I had the choice of a camera with decent cropping possibilities or totally switching systems, a seemingly daunting task. Enter the D800.
At this point, with about a month of use, I can say that I am quite happy with the D800. I haven't pushed it's low light abilities to any limit. Previously, I used my D300 whenever possible for birds, because of the smaller field of view, but I was never really happy with anything beyond an ISO of 800, and that was stretching it. Now, with the D800, I have fine examples of images at 1600, and I will test its ability to go higher.
For the first time since I've owned the Nikon 1.7 teleconverter, I have decent images made with it and the 500mm lens.Overall, the speed of focus is perhaps my favorite feature. The file size and phenomenal amount of cropping possible while still leaving a reasonably sized image has to be number 2.
It's hard to separate the detail preserved in the D800 images from the improved detail that one can get from Lightroom 4, as I added LR just a bit before the camera, but the combination is impressive. I've experimented a bit with Nikon NX again for processing, and I can't really see a difference in the finished product of NX vs LR. As LR is at this point easier for me to use and integrated with Photoshop, I doubt I'll be using NX much.

                                                        Nikon D800, 28-70mm lens @ 70mm, ISO 100, F11, 1/80 sec