On ND filters

For my birthday last year, I was gifted with an ND grad (.6, i.e., two stops) filter.  I haven't used it very much in regular shooting, but a recent trip out to a local tourist trap provided some opportunities to use it.  I've been trying to refine a raw workflow, but my hardware is limited and it has been a bit of a struggle to produce images in a timely fashion.

Neutral density filters are useful for a variety of scenes.  An ND filter reduces the light hitting the sensor by some amount.  This is helpful for scenes with a wide dynamic range (e.g., a sunset) or when additional motion blur is desired.  In the former case, the filters are usually graduated so that the horizon can be set properly:  above the grade, light is reduced; below the grade it is transmitted without change.  This is the sort of filter I have, but it serves in both capacities because it is large enough to fit over a 52mm lens without touching the grade.

Images with discussion following the jump.

Vibrancy and Saturation

Thom Hogan posted a recent article on the difference between color saturation and vibrancy, and it's well worth the read for those interested in how to manage colors in post.  Most cameras have a "vivid" setting that allows users to dial up color saturation in camera, but often these settings blow out colors we'd rather leave alone.  Ken Rockwell is fond of VIVID++!!!BANGBANG!ONE!, but notes that this usually destroys skin tones, for example.

Color correction is a big subject about which I know comparatively little, but he mentions a significant issue when increasing color saturation:  linearity.  A heedless linear increase in color saturation across all spectra will lead to poor results.

While Photoshop has (I'm led to believe) a vibrancy control, the Gimp does not.  (There is a vibrancy plugin, but as far as I know it's not standard.)

A suitable method for increasing saturation in a non-linear fashion is to decompose the image into an appropriate color space and modify the saturation curve.  For the following example, I'll use an image from my shots at Hopewell Furnace.

Black and White Treatment

I've spent some portions of my time shooting limiting myself to black and white for sake of the effects.  One of the images from Getty really worked out well for a bit of levels enhancement and a black and white treatment:

Before

The image is low-contrast and relatively blurry in the original form—manually focusing at 400mm is tough given how thin the depth of field is.  The birds on the posts are generally sharp, and the ones flying aren't.

The levels enhancement helps the contrast some, but it makes the image a little over done.  Fortunately, a black and white treatment really helps:

After

All in all, I think it's quite an improvement—and the print of the black and white version was pretty terrific.  One of my recent favorites, to be sure.

Compositionally it could probably be better (the dark spot in the upper left is a small overhang from a tree a few feet away), but it does handle rule of thirds fairly nicely I suppose.  The blurriness of the image is actually somewhat attractive here, as it helps to distinguish the middle third from the bottom one.  I'm undecided about whether the top third is compositionally useful or not—if not, a crop might serve better to fill things more adequately.

White Balance and Lighting

White balance and lighting are pretty critical elements of good color composition. I'm hardly an expert at this, and all of my lighting experience has been with natural lighting—no flash systems or anything more complex than an SB-400.

This past weekend, I was able to get some pictures of my parents' firebushes. I was really just killing time, not planning anything...but it worked out fortuitously.

I've wanted to post a bit about lighting, but time and experience are both factors here.

The bushes look a bit like this:

24mm, 1/100s @ f/4, ISO 400

This is actually the "pretty" version of the bushes, taken at the end of the set. With somewhat poorer lighting and bad composition, we get something eternally uglier:

White Balance

White balance is really critical, and I wish I had known this a long time ago. When I bought my camera to go to Kenya, I knew even less about photography than I know today—hard to believe, but true. It turns out that the weather was mainly overcast, and this led to pretty drab photos that I wanted to touch up later. As it happens, automatic color adjustments in most software programs are not really all that great: they overcompensate based on slavish adherence to the color or value curves in the image histogram (this doesn't really need to mean anything to you at the moment, but it does give me an idea for another posting sometime). This is okay when colors are normally distributed in the image, but usually they aren't—that's why we want to fix them in the first place.

The drabness of an image is often the result of improper white balancing. A warmer white balance leads to more saturated photos with deeper reds. In shady conditions, this is usually needed to counteract the bluer tones in the scene. Ken Rockwell (linked right) has a good article on white balance that's worth a quick read, and others exist on the web, too.

This is a bit of an article on my experience.

Black and White

There are a lot of variables in photography—maybe that's one of the reasons I enjoy it. The complexity of picture taking helps ensure that photographing the same subject several times never really returns the same result.

I'm mainly a colors person; I enjoy color and in proper combinations I find it compelling and striking. That said, I'm also a fan of geometry (the only math I ever did very well in, and incidentally the best graphics course I took in my CS degree). I realized recently that there are two primary reasons that intro photo courses don't use color.

Before and After

Composition remains one of my worst skills. I usually shoot very instinctively, and unfortunately my instincts are not all that great.

Often I'll shoot out the car—it's no-look shooting, don't worry; I tape the lens at infinity and don't consult the viewfinder—using the 24mm. It's fast enough, and the wider field of view gives a few more options for cropping. Moreover, the exposure is completely manual, which adds a bit of randomness—it's not adjusting to changing lighting conditions. The exposure is sometimes pretty interesting.

I am usually too lazy to edit photos, but I made an exception in this case.