Mathematical Problem

[Freaki Li Cuatre]

So was the height you mentioned earlier the height from ground to top, or height from base of chimney to top? Either way you can easily calculate the hypotenuse and then have all 3 sides of the triangle. You can then scale one side down keeping the ratio the same.

Height of chimney is base of chimney to top.

Picc was taken 1.2 km away 90m below base of chimney

[Zippy]

So is the problem that you don't know the heights of the other buildings?

[alluvial]

So is the problem really that you have a photograph that doesn't actually have a chimney in it.
You now want to add a chimney to the photograph but scale it so that it appears to be 1.2 kilometers away.

[Freaki Li Cuatre]

So is the problem really that you have a photograph that doesn't actually have a chimney in it.
You now want to add a chimney to the photograph but scale it so that it appears to be 1.2 kilometers away.

Yes - exactly that.

[Pondlife]

deleted me talking rubbish

[RedSauce]

Yes - exactly that.

But how tall is the chimney?

[alluvial]

Yes - exactly that.

The relationship between distance and apparent height is given by:
A= h/d

Where A is the apparent height, h the actual height and d the distance from the viewpoint. Google linear perspective.

[rhubarb]

Wouldn't a nice ferris wheel look better than a chimney ?

[Zippy]

The relationship between distance and apparent height is given by:
A= h/d

Where A is the apparent height, h the actual height and d the distance from the viewpoint. Google linear perspective.

That'll give you the apparent height in real life, but to scae it for an image you need to compare against other things in the image. I think.

[Freaki Li Cuatre]

That'll give you the apparent height in real life, but to scae it for an image you need to compare against other things in the image. I think.

That will be hard when the other things in the pic are at different distances though