I assume this is the experiment you have been talking about.
If so, I am willing to participate but I see no reason why you need email addresses.
You should be able to post all the details here or in a pm and just get the pictures and graph sent.
If you need other documents you can share them via google docs.
That way everyone can know they are getting the same instructions.
So what else is required?
I gather you need a grid with something drawn on it with pictures taken from a few different distances?
Also, if this is the form:
https://docs.google.com/forms/d/e/1FAIpQLSeLXshSjVkWswmdGUlh6YztQOk-woesW0MGXMRl2_U7uH4brg/viewformThe last question isn't actually answerable as it depends upon how close it starts and where it actually is.
It only applies as it gets quite small and can be approximated as tan(x)~=x for small x, or to put it another way, where the distance between the different parts of the object are roughly equal.
As an example, an object that is 1 m tall, 1 m away will appear to take up 45 degrees of your vision when you look directly at an end, but 53 degrees if you look at the centre.
If you move it so it is twice the distance away, it will then take up ~27 degrees when viewed at an end, or 28 if you look at the middle.
Note that this doesn't follow a simple relation of being half the angle, it is slightly more than 1/2.
However, if it starts at 100 m away, then it takes up roughly 0.57 degrees regardless of where you look at it (e.g. end or middle) and if you double the distance it will take up roughly half of that (0.286 degrees).