I like the subjects, but I would have approached this a little differently.
#1 I like the arm with the gear at the end, but it's off to the side with nothing to balance it visually, and the values are too close together to be able to easily separate it from the background. I think that this would have more impact had you moved in on the subject quite a bit more and allowed the values to span a larger range. Having shadows allows things that are forward of the background to stand out, while forcing the values closer together makes them merge into each other. They also allow the viewer to discern details and textures better.
#2 Great sense of place here augmented by nice depth of field - I like that we can see all the way back into the area. You've presented some interesting shapes and there is enough detail to be able to linger on each piece. The two-tone feel (brown and grey) works well with this scene. It does have a bit of unnatural feel to it, but in this case it's not so bad that I'm having difficulty with it.
#3 Great subject and a good point of view - we can make out a good amount of texture in the wheel, which is nice. You also did a good job managing the ray of sunlight on the top of the wheel, which would, if allowed to blow out, ruin the impact of this image. In this case the background adds to the feel as well, but I think that moving a bit to the left and getting the other wheel in the shot might have made this even stronger. Moving in closer on one wheel and showing just enough of it for us to get the idea of the whole would have shown off the texture very well as well.
#4 This is somewhat interesting, but needs something more I think. The subject does not have interesting texture or color, but it's not bad either, just not as powerful as some of the others.
#5 Boilers always make interesting subjects - they usually have great texture, repetition of elements, and often pleasing bolt patterns or hinges and name plates. These, however, are too far away for me to really get into them. I like the sense of place that you have presented by including that much of the background, but my eye wants to move in a bit more on the main subjects to isolate the details. The ash bins at the bottom look intriguing, as does that small hopper in the lower left for example. I would also try to pick a point of view where that bright highlight in the background was blocked off - it really pulls at my eye and prevents me from lingering on the main subject. The values are a bit close in this one as well - I think that having a bit more shadow would strengthen the impact of this one.
- Randy