Finding the angle that a photo was taken from

[george013]

Sir, I accept your challenge.

The position of the Sun is defined by two angles - azimuth (angle from the North) and altitude (angle from the horizon).



The Sun visits the same position on the sky twice a year. Once we have identified the two angles, we will have two possible dates and times on which the same shadows can be observed.

After replotting the shadows seen in the image on Google map (we need a view from above to measure all angles correctly) and some trigonometry that I won't bore you with, I got azimuth = 150 degrees, altitude = 24 degrees.

Then we go to a website like this:

http://www.suncalc.org/#/52.1556,-0....0.17/10:57/5.5

and find the two possible answers: (1) 10:30 on 17 October (2) 11:00 on 24 February.

I would say, there is about 1 week uncertainty in the date and about half an hour uncertainty in the time either way. Take a pick.

A wonderful argumentation and explanation. Something just to remember.

George

[tao2]

This has been great fun. Kinda like string theory or quantum physics (with the emphasis on theory ). FFS guys, counting bricks in a photo with an unknown camera and lens ? Ah was so engrossed ah forgot tae watch " Question Time". My tuppence worth. My flat was built in 1929, 7' doors / 9' ceilings. What does that prove...? AYE, correct first time. Ah think the ORIGINAL photo was probably taken with a box Brownie 2... from a window (open). The modern photo bears no relation tae the original, other than it's the same street. Anything else ah add would be conjecture... like this most entertaining thread. But keep going, ah'm thoroughly enjoying this...

[dem]

The modern photo bears no relation tae the original, other than it's the same street.

Of course it doesn't. But WHY? Why do you think all points of view available on Google Street View are limited to one side of the road, the one that has no parked cars on it?

[William W]

. . . The modern photo bears no relation tae the original, other than it's the same street.

I suppose that depends by what you mean by "relation", but in the context of the question asked - that statement is incorrect.

The image in post #42 is an image of the same building that appears on the LH side of the Original Image.

Much information can be gleaned from Google Earth images of the same buildings and structures which appear in the original image.

WW

[tao2]

I suppose that depends by what you mean by "relation", but in the context of the question asked - that statement is incorrect.

The image in post #42 is an image of the same building that appears on the LH side of the Original Image.

Much information can be gleaned from Google Earth images of the same buildings and structures which appear in the original image.

WW

Hi Bill,

Ah assumed it was a given, that it is the same building...

The modern photo bears no relation tae the original, other than it's the same street.

Ah don't see what's incorrect about that statement? The modern shot of the building is a very different angle, distance, perspective, size, camera elevation, tae mention only some obvious differences between the two shots.

Google Earth and Google maps (or both in conjunction) can have anything between 2-40 feet of a difference in positioning, so the use of either or both is moot.

While ah really have enjoyed reading this thread, it is simply pseudo-scientific.

[William W]

Hi Boab,

I think, that we two are thinking along different thoughts.

What I mean is: The modern photo definitely "has a relationship" with the older one, because it is a photo of the same building. Maybe that's what you meant too, but it didn't read like that to me.

If we have many photographs of the same object then we can use all those images; portions of them; comparisons and contrasts of them, to extrapolate or rule out features of the object.

For one example the google earth shot makes it a lot easier to identify the bricks. If we can accurately identify the bricks, then we can estimate, with very little doubt, the height of the building.

WW

[george013]

Hi Bill,

Ah assumed it was a given, that it is the same building...



Ah don't see what's incorrect about that statement? The modern shot of the building is a very different angle, distance, perspective, size, camera elevation, tae mention only some obvious differences between the two shots.

Google Earth and Google maps (or both in conjunction) can have anything between 2-40 feet of a difference in positioning, so the use of either or both is moot.

While ah really have enjoyed reading this thread, it is simply pseudo-scientific.

I've trouble to understand your writing. I didn't know if you meant it sarcastic or not. I don't think so now.

Finding the same building gave the opportunity to estimate the length of that building, not in google street view but in google maps. The height is counted in pixels. The real height will be pixels*z which is unknown.
Off course there is a fault in the measurements, as in any. But if you want it more accurate, measure the house in real life.
When the horizontal lines of that house where perpendicular to the sensor, then I assume the vanishing point would be in the middle of the photo. I'm not 100% sure of that so somebody, Dem, might confirm or correct that. But either way, the change in length will be minimal in this case.
Measurement is always a matter of accuracy. Do you want an answer with a accuracy of 1 mm or 1m? I think 1m is more than enough for this thread.

George