Shadows do not match the time of day when Marty first arrives in 1955. He arrives at nite, then when he gets out of the car at Lyon Estates it is midday, when he hides the Delorean the shadows are long, and when he arrives at the clock tower it is 8:30am.
Well, this is actually something which can be explained simply by watching the movie again. When Marty appears and crashes into the barn, it's midnight. That's what the time circuits were set for. So, it's night time. He was chased off the property and he drove away from the farm. He was driving towards 'home' at this time. How far away is this from the site where he appeared? It's starting to become twilight (is that the right term for the time before dawn? I always get confused about those...) He must have been driving a while, cause that means that it's been at least 4 hours (this is November ... so it's Daylight savings and the sun rises earlier.) He has to hide the Delorian because it's not cranking (out of gas, I think is the main problem, but I could be wrong about that.) He tries to hitchhike, but we know that at least one car refused to pick him up and since he was walking into town, we can assume that he had to walk the whole way there. So, it's 8:30am now. It fits fine. When was it midday at Lyon Estates?
Undrhil
I don't buy your conclusion that it would have taken FOUR hours to DRIVE from the Pine Tree Farm (site of the current day TWIN PINES MALL). That means it would have taken at least 6 hours to SKATEBOARD to the the mall from Marty's house. He could not have possibly gotten there in the short amount of time he took when meeting Doc at the beginning of the movie. The mall can't be more than a half hour from Marty's house.
If it was a 4 hour car ride, it would be more like a 24 hour skateboard ride you moron, but you're right, it definitely wouldn't take him 4 hours, this is a good slipup.
your theories about the shadows are all good, but the real reason is probably that they filmed it at different times of the day and it is a little to much to ask that they change the shadows to mix some unknown time frames.
o.k. I don't know about the time things but about the shadows, if it is cold out the shadows are longer than if it is hot when the shadows are shorter.