Many thanks to new and returning participants! If any of you followed to the end, you have hopefully read the thoughtful commentary that did not include photo examples, but also you have seen the pitfalls of an open forum: how easy it is to get bogged down in lengthy disagreements - or lectures - that, in the end, are only meaningful to those who enjoy debate or the sound of their own voice.

I just spent an hour going back over the thread to produce the below results, and I am gratified and grateful for all those who contributed their time!

To recap using my opening bullet points:

1. Relative size/distance - Photos: randomeyes page 1, camerapapi page 2, Gene51 page 3 where he expressed relative size as SCALE, JD750 page 3 (example of real relative size ), fuminous page 4 for an excellent example of lack of visual cues, via the lens page 4, repleo page 4, rpavich page 5, R.G. page 5, 10MPlayer page 6, RichardTaylor page 7 (excellent use of successful vs. unsuccessful pair to compare), magnetoman page 7

2. Linear perspective, vanishing lines. Photos: Camerapapi page 2, artbob page 3, repleo page 3, mallen1330 page 4, via the lens page 4, repleo page 4, Rich1939 page 6, magnetoman page 7

3. Except with distortion of very near objects using an ultra-wide angle, focal length itself does not cause perspective change. It does cause the illusion of compression or distance, so you as the photographer can use this knowledge and apply it to how you want the image to look. Photos: my apple orchard page 1, R.G. page 2 (comparison shots are such great learning tools!), pmorin page 2, repleo page 3, RichardTaylor page 3, mallen1330 page 4, rehess page 4, via the lens page 4, selmslie page 5, my forced perspective page 6, User ID page 7

4. Atmospheric conditions - color saturation decreases, details become less pronounced. This is one way our brain understands distance. Photos: my haze and fog photos page 2, Gene51 touches on the role of color saturation on page 3. Pmorin page 6

5. The "fun stuff" part, shooting from an angle that's not the everyday view. Photos: my apple page 1, Chaostrain page 2, kenievans page 2, DNW page 3, CO page 2, JD750 page 4, rich1939 page 5, Anhanga Brasil page 6, 10MPlayer page 6, magnetoman page 7

6. (not mentioned in opening) - use of focal point and depth of field, first brought up by artbob on page 2, then Gene51 on page 3.

Again, thank you all for participating!