Lighting is important for any photographic subject. Three-quarter lighting is a term from portrait photography meaning the light shines on both the subject's front and side, yielding a flattering three dimensional appearance. In railroad photography, a three quarter shot is disparagingly called a "wedgie". Rather than artistic, a wedgie is intended to be documentary, highlighting the details of the equipment. Unlike portrait photography, a railroad photographer can't move the subject, but has to plan on the sun being in the right place.
Here's what a back-lighted image looks like:
And here's a three quarter lighting example:
Given a time and date, which locations are good for photographing a train? Not only does the sun move with respect to the rails throughout the day, its path is different throughout the year. For example, in the winter in the Northern Hemisphere, the sun will never shine on the front of a train headed directly north. Another variable is the direction the train is travelling. I made these pages using JavaScript, Google Maps, and Google Charts to identify those locations. So far there are three pages:
Roseville, California
Carpenter Road near Colfax, California
Hakata Minami Station (博多南駅), Japan
Be aware that for these pages to calculate correctly, you may have to adjust your computer's time, date, and time zone so that it matches the selected location. Also, be sure to read the Map Information block for help on how to use the page. You may wonder why a solar elevation of less than thirty degrees is highlighted green. This is because when the sun is low, the details of the undercarriages of locomotives are well illuminated, which is considered desirable in a roster photograph.
To determine where the sun is for any time or location, I used equations, with permission, from a document called Computing planetary positions - a tutorial with worked examples by Paul Schlyter of Stockholm, Sweden.
