Photography - it's a start

[penwash]

I don't want to make this a photo-critic thread, but this is an interesting exercise which shows why a single photo can be taken (presented) in different ways.

I disagree that photos with centered subject are *always* undesirable.

In this particular case, David's photo works as it was presented in the original post, because in addition to the "almost" centered rails, it has other elements that strengthen the composition.

Element #1: The two people in the "background". They provide a good "anchor" for the viewer's eyes.
Element #2: The square metal plate (with 4 rivets or bolts) near the foreground.

The rail now becomes the connector between these two "anchors" and overall the composition makes for an interesting (as opposed to boring) image.

Another factor in composition is image ratio, which is how tall or wide a photograph is. If I were to present this photo, I'd crop it to 3:2 or maybe even 4:3, so it won't look as "tall".