Scratchbuilt model completed

Shrug. If you can't see it then it's because you can't see it, not because the difference isn't there.

(How do you think I could have written the post about the shadows if I hadn't noticed that they were slightly wrong?)

Sure, in theory.

But the photographer in question didn't bother doing so.

At two feet there's likely enough fuzz generated by the eyeball and brain ...

It looks to this eye as if the model photo has had some enhancement, crispening or some such. It is certainly more contrasty than the full- size shots.

Doesn't have to be all that far away to get noticably fuzzy. Here are a couple of pics I just took to illustrate the effect:

This is the shadow cast by one of the posts that support the roof of the patio just outside my computer room. Note that the shadow line is razor-sharp on the right side of the pic -where the shadow and the post intersect- but the shadow has become noticably softer in just the

12" or so before it reaches the left side of the picture.

This second picture illustrates that same shadow as it's projected circa 8' from the post. Note that the shadow transition line has now become at least an inch across.

This effect is even more pronounced when the object casting the shadow is very narrow (such as the steel components of a fire escape); as the shadow diffuses from *both* sides at once, and after only a few feet there is no truly "black" shadow left at all.

Slightly sharper, yes, because the sunlight is passing through less atmosphere at noon. But not 'smallest' or 'shortest' unless the object casting the shadow just happens to be planted vertically.

Let's use a telephone pole as an illustration:

Sitting vertically, it casts the shortest shadow at noon in midsummer.

But if you place that same pole horizontally, with one end facing the sunrise and the other facing the sunset, it will cast the longest shadow at noon, and the shortest ones at dawn and dusk.

And if we now spin that horizontal pole 90 degrees -so that the ends face north and south- it will cast a shadow of the same length all day long...

With the above in mind, it becomes obvious that orientation to the light source is what matters when it comes to the length of a shadow. The time of day only tells you where the Sun is; not how the object in question is sitting in relationship to it.

~Pete

On 1/21/2011 12:17 PM Twibil spake thus:

Since you brought up the subject, and were good enough to include an example illustration, let me reply: with all due respect, I still don't thing it makes much difference. Here's why:

What you say is true, and the picture proves it. *However*, keep in mind that this picture was taken close up, just a few feet away. Take another picture farther away--say, from the roof, or across the yard, and that obvious difference in shadow sharpness will be much less apparent. And if you're about a scale street width away from the subject, the effect (and thus the difference between a model and the real thing) will be even less pronounced. In other words, the apparent difference in sharpness is proportional to the viewing distance.

However, I'm quite willing to admit that your eyes might be better than mine ... judging by your modeling pictures, they're pretty good.

It will?

Maybe I'm not getting your example; you mean a pole parallel to the ground, but above it by some distance? With its axis east-west? In that case, the shortest shadow would still be noon, wouldn't it? Although there would be relatively little difference in shadow length anyhow.

Just trying to decipher your example here ...

Doesn't have to be all that far away to get noticably fuzzy. Here are a couple of pics I just took to illustrate the effect:

This is the shadow cast by one of the posts that support the roof of the patio just outside my computer room. Note that the shadow line is razor-sharp on the right side of the pic -where the shadow and the post intersect- but the shadow has become noticably softer in just the

12" or so before it reaches the left side of the picture.

This second picture illustrates that same shadow as it's projected circa 8' from the post. Note that the shadow transition line has now become at least an inch across.

Now scale it down to 1/87 or even 1/48 and what do you have?

An excellent illustration. A ruler would have helped establish scale.