The Focal Length of a Concave Mirror

[G3CK0GUY]

your man is the next big thing i reckon. handy out night before physics 2011 :P

[emperorofhell]

Go on Adam....you big scientist you, your famous now....can i have an autograph???

Its Aaron

[yerrahyouknow]

The cardboard box is a very nice tip - I need to stock up!

Rather than a cross-hair source I use greaseproof paper with an arrow marked on it, but your source looks more accurate. Do you draw on the same paper or use something else.

Thanks for this.

[c4science]

Thanks. The cardboard box is definitely easier than cramming a human pyramid into our tiny dark room. The source came as part of a Unilab kit. There's a still of it in the focal length of a converging lens video.