How do you use the "lamp casting a shadow method" to enlarge an objects image on a wall.?

[mywhitemustang]

I have a small template on sheet metal that I need to enlarge by about 3 feet. I know you can use a light and something on the wall to project the shadow on and then I can trace the outline of the shadow. What is the trick to getting it to be the size I need while not messing up the integrity of the design. In other words, it needs to be to scale. Move light further away, move template further away, or move both. Somebody make this easier for me please.<br />
Well, I live in a very small town, (no ohps) and I need to get this done tonight. I think I'm confused about the distance of the light from the existing template that I'm trying to make an enlarged copy of. I can make it stable even if I have to resort to my old faithful duck tape.<br />

 

[NeilS0121]

Use an OHP (over head projector), your template would lie on the base, move ohp away from wall - you get a bigger image, move it close you get a smaller image with the added bonus that its stable.
If you're in college/ school/ university ask about borrowing one, otherwise you can rent (or buy) them.


If you move the light further away from the template the projected image will become enlarged - however the projected image will also become fuzzy - thus you loose the integraty of the image.
To keep the projected image sharp you need lens' - thus the ohp.
What about a scanner?
Scan the template, enlarge the template within the computer, then print and cut out, thus you have a larger template, you dont have to move the lamp back so much and you don't loose the integraty of the projected image???
This is hyperthetical I'm afraid, maybe worth a go if you are up the wall and need to finish for a deadline.
Sorry can't be of more help.