Tuesday, August 24, 2010

Photography Case Study: Bathroom Door

(Note: I’m launching Photography Case Studies in response to a friend who asked for some photography advice. We’ll see how it goes; expect the format to change as I figure out what I want to do. Please send your suggestions to jonathan.e.green@gmail.com. This first example assumes you have Lightroom but much of it should make sense even if you do not.)

Before and after: Here are two photos, click for full size.

"Bathroom Door" as it came from the camera.
The first is straight out of the camera: Nikon D80, Nikkor 17-35 f2.8 at ISO 400, 17mm, f2.8, 1/200 sec. RAW (.NEF) with manual WB @4900K. Pop up flash allowed to fire automagically but with prefire via AE-Lock. It’s been two years since I took this photo but I was sure I used manual flash, maybe the EXIF is wrong. The second has been post-processed in Adobe Lightroom 2.

"Bathroom Door" after post processing in Adobe Lightroom 2.5.
Feel free to jump ahead to ‘Conclusions’ and skip the technobabble.

This is a two-color composition. In post I worked hard to make the red towel as near to black as possible (via reducing the red channel luminance) but did not want to crop it out, as it counterbalances the doorknob. A close examination of the two photos will also show I removed traces of blue and green from the knob crystal (via zeroing saturation).

I did do some significant cropping including rotation to make the door nearly perfectly diagonal across the frame. Because the cropped image is so nearly perfectly square, I let the door remain a bit off 45° so it would not meet the corners of the frame.

Lens characteristics.
Newer Nikon cameras automatically remove LCA (lateral chromatic aberration, usually seen as green or red tinges on sharp lines near the corners) with most Nikkor glass, and newer designs than the 17-35 – especially the legendary 14-24 – are regarded as superior. The D80 is not one of the newer designs and does not make these corrections. However, these facts do not concern us here. Even if LCA was present it is cropped out in the final result, and you’re welcome to click on the original to see if you can find any in the out-of-camera at full size.
The 17-35 and SB-800 on a D90, successor to the D80.

Note the distortion caused by getting close and at an awkward angle. (This is good, see Ken Rockwell.) Most lenses have some form of distortion, often complex and variable depending upon focus distance and zoom. This composition depends on strong lines. By skewing the lines I am able to reduce the effect of the distortion in some aspects while using it to my advantage in others. If you hold a straight-edge to the door, you will notice there is just a bit of “push” distortion, unnoticeable without close examination but subtly, subconsciously, noticed. The inward bow of the line helps the illustration of depth. The top line of the door, above the knob-plate, is converging toward the main line of the door at some point beyond the top of the photo. Along with the shadows in the top of the photo, it may detract from its composition as it threatens to lead the eye away from the knob.

Camera configuration.
Rockwell is correct when he says to get as much right in-camera as possible. There are amazing capabilities in post, but you’re stuck with what you’ve got when you pull the trigger. Get it as close to correct when you release the shutter. This particular composition is the sixth frame of similar attempts, not counting any number of tries I erased in-camera. If I were serious about it, I probably would have made closer to 50 attempts, trying to get the camera settings as near perfect as possible. Also, I was experimenting with RAW when I took this photo, I shoot almost exclusively in JPEG. Your mileage will vary.

Exposure was manual with center-weighted metering. In hindsight, I wish I had used a slightly smaller aperture (higher f stop number) for greater depth of field. The point of best focus is in the doorknob while the door itself – arguably the emotional center of this composition – is lost into fuzz due to the large aperture. At ISO 400, noise is generally well dealt with until you begin squinting at 100%.  The camera was handheld and VR (image stabilization) is not available on the 17-35. The D80 (long supplanted by the far, far superior D90 which is itself due for replacement) has a difficult to work with rear LCD, otherwise I may have done a better job setting white balance (4,900K in camera, adjusted to 5,700K in post, one of the benefits of shooting RAW).

Shot technique.
The bathroom this was shot in is small and it was a contortionist exercise to align the door with the cupboard behind it and to come as close as possible to a 90° intersection with the wall molding. I ended up climbing into the bathtub and holding the camera away from my face against the tub.
The 17-35 (not pictured) is significantly wider than the 18-105 DX VR
(top) and weighs about the same as the 70-300 VR (below).
The 17-35 feels like it could be used for self defense.

If I had taken this photo with a better low-light performing camera (D3s anyone?), I would have tried for a higher shutter speed and the aforementioned smaller aperture, at say, ISO 1600. This introduces further problems, however, as most cameras flash-sync at 1/200 or 1/250 without an external FP flash. (I did have an SB-800 available but due to the close quarters of this shot – the front of the lens was probably about four inches from the doorknob – an external flash would have given a vastly different perspective.) Lighting, arguably the most important part of a composition, can be difficult to control.

I knew I would have to crop after experimenting to find the best position for the camera and its built in flash. Several attempts were required to find the balance of light and shadow seen here.

Post processing.
The WB was dialed up to 5700K, otherwise the white of the door was too cool and clashed with the yellow behind. (Refer to the before and after and notice how the door looks like it was lighted by a flashlight or … camera flash … without the adjustment.) Exposure and overall saturation were unchanged, as was fill light (again, these are Lightroom-specific but also broadly applicable to other software). Recovery was increased to maximum, increasing the depth of the door, while blacks were dialed up to 23 to support the contrast increase (to +50, as was brightness). Clarity was adjusted to maximum to highlight the stroke of the white paint on the door and the reflection within the knob.

There were significant adjustments made to HSL (hue, saturation and luminance). The green and aqua channels were completely desaturated and the blue channel reduced by 60%. The red channel was boosted to maximum, orange to 55% and the other channels were let alone. The yellow hue slider was pulled 30% toward orange (center is yellow, right approaches green) and the orange hue was tuned 25% to red from yellow. Sharpening was significant, producing the almost comic mosaic in the knob crystal.

Finally, selective and subtle post-crop vignetting was added. Vignetting helps keep the eye in the center of photo, instead of wondering off the edges, but it should be so imperceptible as to go unnoticed, even when looked for, unless the original is available for direct comparison. I determined the specific vignetting adjustments by trying to create a square in the upper left-hand corner, where the dark ceiling meets the door. Did I succeed? (See pink lines on Figure 1 below.)

This composition relies on three things: lines/intersections, color balance and negative space.
I worked to make the lines as close to straight as possible, knowing the limitations (distortion) of the lens I was using. (I have thousands of archived images from this lens alone, so I know how it behaves.) Where necessary, I used distortion to my advantage. I also worked hard to make sure the lines intersected as close to 90° or 45° as possible. There was considerable trial-and-error involved in just this portion of the composition.

I remain unconvinced yellow was the best color to balance against the white of the door. Even after lengthy white balance adjustments in camera and in post processing and additional color correction in post, I’m not sure it’s the best color. Unfortunately, the walls in this bathroom were yellow and regular light bulbs enhance the effect. I should have found a black towel instead of the red one in the image, I think, although that shade of red seems an appropriate balance with the yellow.
Figure 1.

There are three negative space weightings against positive space (see Figure 1). The first and most obvious is the white door against the negative yellow background (green line). The second, and most awkward, is the knob versus the towel and to its own shadow (both roughly triangles, but differently proportioned and not in logical tension, cyan lines). Finally, there is the square in the upper left-hand corner (magenta line). In a perfect world, the towel would be hanging a little higher so to more closely match the doorknob, while the square in the upper left would not threaten to steal your eyes off the image.

Image grade.
Original: B -
Post: D +

The before-and-after image grades are not meant to mean that I think the post processing harmed the image. I simply think I got more out of the original, closer to what I wanted to capture, than I was able to do in post. I prefer – vastly – the post-processed image. I suspect it will be difficult to find a composition that scores well both before and after, although I have hard drives and DVDs full of compositions that would score poorly on both counts.

I welcome and invite suggestions for this column and critiques of this composition. Please leave a comment on the blog or email me at jonathan.e.green@gmail.com. I suggest you put “Photography Case Study – Bathroom Door” in the subject line so I find it if Google’s excellent SPAM filter eats it.

Next time...
Depending on your feedback, I'll discuss the polar opposite of this image: an award winning photo of search and rescue folks pulling two men off Boysen Reservoir two winters ago when the mercury was afraid to show itself. There was no time for careful composition (or was there?) and there were certainly no second chances. What did I do to get it on the first attempt, and what did we (at the newspaper) do in post? Tune in next time; we'll shoot for Friday.

"Hell's Freezing Over" 2009 Wyoming Press Association Spot News Photography 1st Place. Air temp -6, wind chill -22.
As it appeared in the newspaper on 18 Dec. 2008.

1 comment:

Anonymous said...

you did a great job. The info is greatly appreciated