On March 6, 2014, I was poised to make an image of Irish Rail 085 (in relatively fresh grey paint) using my Canon EOS 7D with 40mm lens. Before the train arrived, I made my requisite test exposure.
I always do this. A test exposure insures the camera is working and is set properly. It also allows me to fine tune my settings to optimize the amount of information captured.
In this case, I realized that to obtain the best exposure and retain sky detail, I would necessarily need to allow the ground and primary subject to be bit dark. However, since I can adjust this in post processing, I opted for the darker exposure.
I could have simply used the ‘levels’ or ‘curves’ feature in Photoshop to lighten the image. This is my normal quick adjustment. However, I thought I’d experiment. So I made series of localize contrast adjustments using the ‘Magnetic Lasso’ tool.
My aim was to even out the relative exposure of various areas, and specifically to reduce the extreme contrast between the sky and the train’s shadow areas, with an ultimate goal of presenting the scene in the final image as it appeared to me at the time of exposure.
I had no intention of exaggerating or distorting the effect of the overcast morning, but rather to correct for some of the inherent limitations of the camera system.
Below are a series of images that illustrate the steps of my contrast adjustment. I’ve intentionally grossly exaggerated adjusted areas as to make the process more obvious. My actual adjustments were relatively subtle. It is my feeling that if the process becomes obvious, the end result will seem artificial.
This is a JPG from the camera RAW file. I made no adjustments to the picture other than convert and scale the file for internet presentation). I intentionally exposed the scene to retain detail in the sky, recognizing that with a digital image detail is lost when an area is over exposed, while it is easy to adjust contrast and brightness after the fact in darker areas.Using the ‘magnetic lasso’ tool I selected the lower area of the photo and adjusted contrast and exposure using the ‘curves’ tool. Please note, I’ve exaggerated the selected area; my actual adjustments were subtle.For the next step, I again used the magnetic lasso to select the darkest shadow areas of the locomotive and wagons, then lightened this selection using the ‘curves’ feature.Although the sky had sufficient detail, I felt that it would be best to make this area slightly darker as a interim step in preparation for an overall lightening of the image. To avoid an unnatural darkening of the Wellington Testimonial, I carefully excluded this from the sky area. I then lowered the contrast and darkened the sky using the ‘curves’ feature.This is the image following the global lightening. While this is very close to how I saw the scene, I felt it still required nominal contrast adjustment as it appears slightly ‘flat’ (contrast levels too low).This is my final image following my multi-step contrast adjustment experiment. Notice, that while the sky is relatively bright, I’ve retained detail in the clouds.
I’ve long been intrigued by the short section of the former Southern Pacific Bayshore Cutoff at the old Potrero Wye, where the railroad runs beneath I-280.
This location offers a graphic contrast; the immensity of the highway shadowing the railroad both literally and metaphorically.
The location also poses a photographic challenge. During high light, the tracks are completely within shadow, so I’ve found the best time to photograph is early in the morning or late in the day, when sunlight is below the bridge.
Yet, low sun also poses a problem, as calculating exposure is neither intuitive nor can a camera meter be relied upon. The overwhelming highway structure will tend to result in overexposure as a camera meter tries to compensate for the darkness, yet the side of the train reflects the full brightness of the sun (which to further complicate matters, may be less than sun at midday).
I made this photograph of an inbound Cal-Train ‘Baby Bullet’ in April 2008, using my Canon EOS 3 with a 50mm lens on Fujichrome slide film. I used my Minolta Mark IV handheld meter in reflective mode to sample the exposure on the side of a gray highway support column, and preset my camera accordingly. (I didn’t make note of the exposure, but it was about f5.6 1/500th of second.)
The resulting color slide looks just about perfect, but my exposure/contrast problem was repeated when I went to scan the image.
My first scan of the slide resulted in this unacceptably dark and contrasty image. Specifically there was compression of the exposure curve that resulted in highlights that are too dark and a serious loss of shadow detail. I’d made this scan using my Epson V600 with the auto exposure feature ‘on’. Obviously to get a better scan, I’d need to take exposure matters into my own hands.
Here, I found the scanner software’s auto exposure had the reverse problem of my in-camera meter and tended to underexpose the scan. The result was not only too dark, but unacceptably contrasty.
I switched off the auto exposure, and instead used the software’s exposure histogram to set exposure manually as to better balance the highlight and shadow areas. Using this setting, I made a another scan. Afterwards, I fine-tuned the improved scan using Photoshop to make for a more pleasing image by adjusting both contrast and color balance.
This is my second scan. To capture the full dynamic range of the slide, I’ve broadened my exposure curve manually. Notice that there is considerably more detail in the shadow areas than in the original scan. I’ve allowed the over all image to appear relatively flat in order to obtain as much detail as possible between the extremes of highlight to shadows. This is an intermediate stage, as the image still doesn’t please me.I imported the second scan into Photoshop and then manipulated the color balance curve to compensate for an excessive red balance (likely the result of a processing inadequacy; specifically in the shadow areas, possibly the result of very slightly exhausted, or under replenished, color developer) then made a slight adjustment to the exposure curve to make the highlights slightly brighter and shadows a little darker. I still wasn’t satisfied. The image was neither as I remember it, nor as it appears in the slide. So went back to the second scan and made a new set of modifications, see below.Here is the fourth version of the image, and in my opinion the version that most accurately interprets the scene as I saw it. I’ve further manipulated the exposure curve to improve the highlight and shadow contrast while retaining detail in both areas. I was also less heavy-handed in my color adjustment because I felt that a warmer tone suited the scene.
This image is an exception; most of the time I’m satisfied with my first scan. Incidentally, the pictures reproduced here are scaled Jpgs from very large Tiff scans. The file size of the Jpgs is just a fraction of the original scan size, which is adequate for small-size internet viewing.
New England Central’s local freight with locomotive 3015 idles in front of the Palmer Yard (Massachusetts) office. I exposed several images, this one was at about 15 seconds.
The other night in Palmer, Massachusetts an arctic breeze was blowing, but that didn’t stop me from making time exposures to capture the holiday spirit.
I exposed these photos despite numb hands and cold feet. I used my Lumix LX-3 (choice night camera in cold weather) fitted to a large Bogen tripod.
Years ago, I fitted plastic-foam pipe insulation to the tripod legs (as per recommendation by experienced cold-weather photographer Mike Gardner). This makes it easier to handle the tripod when it’s very cold.
My exposures varied from about 1.6 seconds at f2.8 (ISO 200) to 25 seconds at f4.0 (ISO80). I set the camera manually using the histogram from test exposures to gauge my settings.
Christmas lights on dark nights make for exceptionally difficult contrast. If you overexpose to allow good shadow detail the lights get blown out (losing their color[s] as a result). Underexpose to feature the lights and the sky and shadows turn to an inky black.
Somewhere in between is a compromised setting. Rather than ponder the subtleties of the histogram as the blood in my toes congealed, I opted to take a series of images, one after the other, and select the best of the bunch in a warm environment later on.
Palmer’s star railroad themed restaurant is the Steaming Tender; this has been colorfully decorated with holiday lights. I made a series of exposures from several angles. This one was exposed correctly for the lights and looked good in the histogram, but appears too dark in my opinion. I prefer the image below.This is about one stop brighter. While I feel it looks better overall, one noticeable flaw is that the ‘Steaming Tender’ sign is overexposed and the lettering isn’t readable. Ultimately the solution may be to blend two images of different exposures in post processing, but I’ve not bothered to do that yet.New England Central’s 3015 pauses in the yard for a 25 second time exposure. I wonder if the car adds an element of interest to the photo? If not now, maybe in years to come. Lumix LX3 photo.Looking toward CP83 (interlocking at the west end of Palmer) and the old Union Station (now the ever-popular Steaming Tender restaurant). A westward CSX intermodal train from Worcester is gliding through the scene. I exposed this at about 5 seconds at ISO 200. It is about 1.5 stops ‘over exposed’ as per the camera meter, but by using a much lighter exposure I’ve captured the effect of the moonlit high clouds and textures of the snow. On the downside, some of the Christmas lights have blown out (become seriously overexposed).
