WARNING! Artists' materials are very dangerous and can cause
injury or death! Use in a well-ventilated area, read all warning labels, and keep out of
reach of children! Use at your own risk! I want to show you how to use a proportional divider. It's very easy to use. That's why they're so great. You measure with the small end, on this side. Not the big end.
If I want to measure something, I use the small end. Measure the height of the vase like that. I've lined up the top with the top of the vase, and here with the bottom of the vase. I just turn it around and put that on my canvas. That would be the top of the vase,
and the bottom of the vase. If I want to change the magnification of that — and you would never change where the screw is during the middle of a painting, this is something you would determine
at the very beginning, and you would never move it again — but if I want to move the screw now, and I move it toward the small end, it's going to give me a lot more magnification. If I take it and put it in this hole, this is going to be extreme magnification, where you would measure
the height of the vase like that, and your vase would end up being that big. So, that's way more magnification. On the other hand, if I move it to the middle, I get very little magnification.
Now, they're almost the same. When you first start to use your proportional divider, you determine how big you want to paint whatever it is, your vase, or your car, or your mountain, or whatever. Then, you would move this accordingly. So, if I put it right here in the middle, and I measure this vase, which is about four feet from me, I would get a vase that is that big. Which is about life size. See, it's about the same size. So, to make that vase life-size, I would put it
in this hole right here.
I would measure and that would give me a vase that is that high. If I measure the width, it gives me a width of that wide. That's basically how you use it. Let me show you some other things
about using a proportional divider that makes it more accurate, and this is really important. The biggest problem with the proportional divider — by far the biggest reason that they may not be
as accurate as you would like them to be — is that when you hold out your proportional divider, if you measure from here, and you measure from here, a little closer, or a little bit further back, it really changes what you're
going to get for a measurement. So it is really important that your chair stays exactly in the same spot, and that you hold your proportional divider the same distance from your eye.
If you keep your shoulders square to your subject and you hold your arms straight out, and you get in the habit of doing that, then you don't have to worry about that so much. You want to keep the distance
of the proportional divider to your eyes exactly the same. I can always do that by
keeping my shoulders square, and my arm straight. Now, that's always. If I'm going to paint a landscape, then I don't worry whether I'm leaning forward or whether I'm leaning back. You still have to worry about this. You don't want to measure one time like this,
and one time like that. What you don't have to worry about is getting closer to your subject or further away, because the mountain is so far away that it's not going to make any difference.
Even a tree fifty yards from you is plenty where you don't have to worry about that. But if you're going to be painting a still life or somebody in the room with you, then it's real important that you always
measure the same distance. So, what I do is I hang some string down. What I've done is I've put this string in here, this yarn, and you can just attach it to the walls
on the sides of your studio.
This string is perpendicular to my line of sight. So that if I'm sitting here, and I'm looking, my view should be straight,
perpendicular to that string. Not like this, not like this. With my chair in the right spot on the floor, and my subject is right there, that string is exactly perpendicular
to my line of sight. So, that's number one. The other things is if my chair is in the right position, and I hold my arm out straight, comfortably, my proportional divider is exactly where the yarn comes down,
or the string comes down. That way, when I measure, I'll know if I'm measuring here, or I'm measuring here. If my chair is in the right spot, my shoulders are square, my arm is straight, and I've got my proportional divider right between
these strings, then I can be sure that my measurements
are going to be dead on, exactly right, every time. What I do, if you look at this string, I've got it on a slipknot up here, and I can slide these either way.
Always use the strings when you're using
a proportional divider. It's just so easy. And if you don't want to
set up all of this, you can even just have a single string that you hang down, so that you can make sure that you're not here, or here. That's basically how you use a proportional divider,
and how you set it up. If you want to learn more about how to actually draw with the proportional divider,
then you need to watch the other tutorial about drawing in proportion.
That's how you set up and use a proportional divider
to draw accurately..