Howard,

Thanks for your letter. I did a little more thinking about the problem:

> What I would like is to export it at 20 ft to the inch - what DPI
> would I have to set to get this scale? I am afraid I don't quite
> follow the help file here. Walls specifically allow me to set this
> scaling - which is what I use when sketching to scale, and adding
> notes as they come out of the cave.

When Windows displays an image on the screen, it does it at a certain number
of Dots Per Inch (DPI). It is usually 96 DPI, but it may be a different
value. You can find the current value by right clicking on the
Windows-Desktop background and selecting the "Properties" option. On the
"Settings" page, press the "Advanced Button" and you should see a "DPI"
value on the "General Page."

When I display an image in Compass, I configure Windows so that the cave
plot matches the screen scale. In other words, if the Compass scale is 100
feet per inch, a 100-foot passage will be one inch long. More importantly,
if Windows is set to 96 pixels per inch, the shot will be 96 pixels long.
(In reality, the actual measured length will depend on the size of the
monitor, but the main thing is that Windows thinks its 96 pixels long and
thinks that value is one inch.)

One of the reasons I do this is because Windows will now guarantee that the
printed plot will be exactly to scale no matter what kind of printer or
plotter you are using. That saves me having to do anything special with
different kinds of printers.

With the WMF/EMF files, I can specify the size of the image in pixels, but
since I don't know how it will be used, I don't know how it will be
displayed. For example, if the image is 100 ft per inch on a 96
pixel-per-inch video display, it will be on 32 feet per inch on a 300x300
printer. As a result, the key thing is knowing the pixels-per-inch of the
display device. This is why Compass allows you to adjust the DPI. It's also
why it shows what the scale will be at that specified DPI.

I'm not sure how Illustrator handles the Meta Files. It could be that it
just assumes the DPI is the same as the printer or the screen. If it is the
same as the Printer, you could try something like 300, 600 or 1200 DPI,
which are typical printer resolutions.

Here are some steps you can follow to test that theory:

1. Find out the screen resolution of your system. It is probably 96-dpi, but
you probably should check using the method I described above.

2. Use the following equation to calculate the Scale you need:

Compass Scale = Desired Scale * (Printer DPI/Screen DPI)

As an example, let say you want 100 feet per inch and you are using a
printer DPI of 300 and Screen DPI of 96 you'd get the following result:

Compass Scale = 100 * (300/96)

Compass Scale = 312.50

3. Go to the "Action -> "Scale, Magnification, Rotation" option on the menu
bar and enter the new scale value. In this case, it would be 312.5.

4. Now go to the WMF/EMF export option and set the DPI to whatever you have
chosen for the Printer. In this case it would be 300. The Scale display in
the WMF/EMF should now show 100 ft/in.

5. You now should be able to export the Meta File at the proper scale for
that DPI. Now read it into Illustrator and see if it works.

If it doesn't work the first time, I would try several DPI's like 600, 1200,
2400, etc, because these are common printer resolutions and it is likely
that Illustrator is using one of them. At the very least should be able to
find something that works by trial and error.

If this concept works, I will add a feature that will allow you to set the
scale directly in the WMF/EMF dialog box. If it doesn't work, I will look at
the problem in more depth when I have some time.

Let me know what happens.

Larry