How to determine height of building to figure out shadow length

Does anyone out there know how to accurately determine the height of a building remotely?

 

I have several shoots that i need to do in the city and surrounding buildings create a challenge when determining the length of a shadow on the street and side of a building. I found a calculator that can give you the heigh if you have the:

 

1. distance from building from where you are standing

2. angle to the top of the building from where you are standing

 

I use the sun surveyor app most of the time and it can measure distance on the ground and give you an angle to the top of the building, however, I'm not sure how accurate it is based on some testing done on known heights of existing buildings.

 

The safe route would probably shoot at high noon to avoid shadows altogether, but I still would like to shoot the buildings in the best possible light later or earlier in the day.

 

Any ideas would be great.

Thanks

Owen

#3 back to Boy Scout days works well enough - #1 I don't use phones. #2 don't own the gadget so can't comment on those.

Link Measuring Heights Without A Tape Measure

thanks for the reply Sandy, unfortunately, these techniques require you to be on location. I think i may just have to do a guesstimate based on how many stories the building is.

Very quick and dirty method, if your camera has some kind of distance readout (lens barrel markings, digital focus distance readout).

 

Stand at foot of building, focus on the top corner.

require you to be on location

 

For sure.

 

Count the stories. Close enough for government work, I think.

Storey - Wikipedia

 

14 feet (4.3 m) total; however, it varies widely from just under this figure to well over it.

As an electricity supply engineer it was sometimes necessary to estimate the height of a pole or other structure, and I was shown a method of doing this by an "old timer" using a short stick, even a length of straw. First identify a point on the pole at a known height, typically your own height, or perhaps the standard height of a danger notice. Then standing a reasonable distance from the pole, hold the stick at arms length so that it just reaches between ground level and the point you identified. Then raise it so that the bottom of the stick coincides with the identified point, and note where the top of the stick comes to. Repeat this until you reach the top of the pole, the height being the original height of the identified point, multiplied by the number of times the stick was raised.

 

Well, you did ask.

Try The Photographer's Ephemeris. (TPE) That might be able to do it as it places the sun and you can calculate distances.

Determining the length of a small shadow on a surface is as easy as using a measuring tape or yard stick to measure the shadow. But for larger objects, such as a tall building, determining the length of the shadow is a little more difficult. It is not always practical to manually measure a shadow’s length. But if the height of the object casting the shadow you want to measure is known, you can use a formula to determine the length of the shadow. A shadow's length varies depending upon the angle of the light source.

1. distance from building from where you are standing

2. angle to the top of the building from where you are standing