Focal length of the lens

Eyepiece focal length

Focal length

Focal

Focal Length

Focal Length

Focal length

Focal Length

Telescope focal length

35mm equivalent focal length

That's this distance right there.

And that's what we set out to figure out in the beginning.

There is an equation that governs all of this, and it looks about as follows

That's just this distance right here.

Well, the first thing you do is though I've never well, we could just figure out the focal length just by plugging into the formula.

So let's solve for the focal length.

Set here equivalent focal length assuming a 35mm film camera, in mm. A value of 0 means the focal length is unknown.

An object at range of 100 meters

I'll do it on this right one here.

Check one.

Bifocals.

Now we're asking you what is the focal length if an object of size 20 m that is 400 meters out if we observe it to be 1 mm on our projection surface.

Same thing, that's this line.

How far away is the object in meters?

So this work is nothing but like because of the focal length of the lens, it just shows what is on the other side.

And you essentially divide 1 by 4 times this value.

The square root of that.

He is 10 meters away from the camera, and the focal length is 10mm.

The distance of this point to the image plane up uppercase Z.

Which we already learned is b.

This is our focus.

We also know that the projection of the building on the internal chip is 4mm in size.

Let's take it right there.

Well, we know the minor radius is a, so this length right here is also a.

Now the definition of a hyperbola, one of the definitions of a hyperbola, can be the locus of all points where you take the difference not the sum, you take the difference of the distances between the two foci, so if

Set here the lens focal length in millimeters used by camera to take the picture.

You don't really have to consider them.

Is this True of False? Please just check one.

Finally, say a known object is 300 m away.

So f squared minus a square.

We know that the baseline is 0.2 mm, and the object is 50 meters away.

In fact this is equation of the hyperbola but instead set of writing b squared, since we wrote it, we essentially said, what is the locus of all points where the difference of the distances to those two foci is equal to 2a?

And there was a bright spot up there.

So they're very closely related.

Distance of the subject from the lens