When you bring a bitmap image into DesignCAD it will be scaled relative to the screen image.

1. If you open a blank file and then import an image the program puts the image into the drawing according to some mysterious relationship to the area visible on the screen.

2. Now zoom out (-).

3. Import the same image and it will go into the drawing with the same relationship to the visible area, and not to the objects in the drawing. In other words, the second image will be larger than the first.

4. Zoom in quite a way (++).

5. Import the same image again and it will go into the drawing with the same relationship to the visible area. In other words, the third image will be smaller than the second, and probably smaller than the first.

All three bitmaps will be different sizes, even though they are from the same image file!

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If you want to import multiple images and have them come into the drawing at the same scale (say you want to import multiple scan images of parts of a map, or parts of a larger drawing):

1. Start with an empty file (best choice)

OR

Select an empty layer and disable all visible layers.

2. Draw a line. Any length will do. This line will be the import reference, and the layer will be the "reference layer." It is a good idea to name this layer "REFERENCE LAYER" in the "Layers" dialog.

3. Use "View/Fit to Window" (CTRL W) to zoom the screen so the line fits the display area.

4. Import a bitmap. Either select an empty layer first, or move the image to another layer after importing WITHOUT ZOOMING.

5. Return to the "reference" layer.

6. Repeat steps 3, 4 and 5 until all bitmaps have been imported.

IF all of the bitmaps were created at the same pixel density (dots per inch) this method will bring them all into DesignCAD at the same relative scale. However, the bitmap scale will not be at a predictable scale to any objects in the drawing before you imported the bitmaps.

7. Use the "Dimensions/Units" (U) function to set the drawing units relative to the bitmap image(s). Find a part of the bitmap image(s) that is a known distance. Press "U" to start the "Units" function, point the cursor to one end of the known distance and left click, then point at the other end of the known distance and left click again.

Now enter that distance into the "Drawing Units" dialog box. This scales the drawing units relative to the features in the bitmaps.