Alan writes: I already wished for a digital range-finder. I'm now wondering if I could rip an old-fashion optical one off an old camera?? Any ideas? you have a couple of methods you could try - the paralax style rangefinders http://en.wikipedia.org/wiki/Coincidence_rangefinder laser rangefinders like this one on ebay http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&rd=1&item=380070431061 or estimation (based on target height) range guessers - and if you want to use a computer to do it for you ;) http://diylab.webnode.com/range-estimation/ or a scaled reticle http://preview.tinyurl.com/65jvfx "Using the Rangefinding Reticle Scale - The vertical scale (reticle) visible through the left half of the binocular, above the compass display, allows calculation of distance to an object if its height is known or calculation of height if its distance is known. Each mark on the vertical scale has a value of 5 MIL (1MIL is equivalent to an angle that can determine an object one meter in height at a distance of 1000 meters). Thus, if a navigation chart gives the height of an object, by sighting on it and counting the number of MILs in the reticle, you can determine its distance. Here are the pertinent formulas: To measure distance when the height is known: [Objective Height (m) / Scale Reading] X 1000m = Distance in Meters." Two more gadgets I'd really like to have. 1. Audible level. Think about it - a tone when the camera is not level. Cool! go nuts with mercury tilt switches :) http://www.russell-scientific.co.uk/mercury_switches/mercury_switches.html 4 of those triple wire switches should do the trick hooked up to a really anoying beeper/buzzer - arrange 2 north/south at slight angles so tipping it a *fraction* and a contact will be made, same with 2 arranged east west. All four centers ties to say +, all ends tied through LED's for a visual prompt which way you need to tip to correct.. tie all the LEDS together then feed the earth through a buzzer circuit 2. Laser pointer remote switch - closes a circuit with laser pointer blast. a flash trigger will probably go nuts at a laser hitting it - mine does :)
