Smokemachine backs you lot up but he seemed to understand about not allowing for angled view by looking through the bottom of the tube at a level.
That still allows for an angled view, it just prevents a downwards view. You still see up high.
But that is not simply looking through a tube, and it definitely is not looking level at a cross hair which needs to be centred.
I'm setting up the tubes and crosshairs in such a way as to be viewed perfectly level...or close to it, giving you very little opportunity to create an angle
If you want to prevent any angle, you need to replace your tube with an infinitely long one.
Any finite tube will produce an angular FOV which will allow you to see below it.
The only question is how large and thus what angle it gives.
In order to see a continuous downwards gradient, all that is required is for the FOV to be more than twice the gradient.
You people are the one's being, either dishonest or unbelievably inept at understanding what's being put forward.
And of course, more pathetic projection from you.
If we are the dishonest ones rather than you, why do you refuse to do the experiment yourself and post your results?
Why do you refuse to do the experiment I suggested?
Why do you refuse to answer simple questions which clearly show you are wrong?
You're using scopes and naked eye FOV to claim you see ground on a gradient.
No, I'm using a tube and simple logic. Something you seem to be unable to cope with.
Again, what magic stops the blue line?
Until you have an answer, there is no reason at all to think you would not be able to see an object along that line.
And again, if you can see it with the naked eye, with a FOV significantly larger than the tube, and with a scope, with a FOV significantly smaller than the tube, then you can certainly see it with just the tube.
Again, see the little grey bit in that diagram?
That is a lens.
What you are appealing to is not a simple tube. Instead it is a tube with a lens which gives it an infinite zoom, an infinite magnification.
There is a very simple way to determine the magnification for a lens, look at what the FOV is on each side of the lens and divide one by the other (out/in).
i.e. if light comes into the lens with a FOV of 1 degree, and the lens makes that hit the eye over a FOV of 10 degrees, that would have a magnification of 10 X (i.e. 10/1)
But what you have is more like 10/0, which is infinite.
So you definitely need a lens for that.
And with such a lens, in order to see the ground, or any object below a straight line parallel to this 0 degree FOV, it would need to be infinitely far away.