distance measurement

[dennis]

it works as described if he walks at 90 degrees to where the object is.

Its then a right angle triangle with 45 degree corners.

[dennis]

I can get pretty good distance measurements using my camera and reading off the scale on the lens after focusing.

[The Natural Philosopher]

Correct. The angle should be 60 degrees.

[The Natural Philosopher]

Attach barometer to string, whirl round and let go till barometer flies over objcect.. Pull back till barometer juts falls off object,. Mark string with felt tip. Pull barometer back and measure distance from barometer to felt tip mark Simples!

[dennis]

Rubbish! ;-)

[Alan Braggins]

The golf one does, but the sniper (laser) one doesn't. Alternatively

:-)

Lasers marketed for archery:

[Bill Wright]

Come on, what are you up to? You're up to summat aren't you? Summat a bit surreptitious I'd say.

Bill

[Vass]

:-)

[The Natural Philosopher]

The easy way to determine how far away a wind turbine is, is to look up the tower height, and use a sextant to measure the angle subtended by the base and the tower tip.

That should be enough to get the azimuth on your black powder cannon properly adjusted....

[bert]

Nor an angle grinder

[Bill Wright]

That is completely impractical. I suggest the following. Using a radio-controlled model helicopter lodge a very loud radio on the distant structure. By comparing the sound from that radio with the sound from a nearby one tuned to the same station it will be possible to work out the distance, since the speed of sound in air is almost a constant. I know this works because I used the method to measure the dimensions of our backyard, using my DAB radio for the distant one and my FM radio for the nearby one. I now now that my yard is eight miles by five miles, which is very pleasing since I intend to build a wildlife park in it next year, as soon as I can find a bank to put the money up. What's wrong with the banks by the way? Lloyd's actually did bother to send a man round to look at the yard, which is more than the others did, but the loan application was still refused. Well it's their loss, that's all I can say.

Bill

[Andrew May]

How accurate do you want it? Old fashioned rangefinder cameras used to have a split image for focussing. The distance could be read off the lens.

Many years ago I had a manual version that fitted onto the hot-shoe. Look through the rangefinder eyepiece and adjust a wheel to get to images to overlap. Read distance off the wheel and set the lens accordingly. Can't have been that expensive.

Andrew

[Andrew May]

Or build your own ...

is uk.d-i-y after all.

[Dave Liquorice]

Still need to sight back to the orginal point, this time + or - 60 deg rather than 90 deg when the second sighting to the remote point is 45 deg.

[Colin Stamp]

I just got home and dug mine out. It's one of these:-

the range was more than I thought. I reckon it'd be fun trying to measure the full 80 metres in daylight on a non-ideal target with it though.

It cost a fair bit more than 50 quid. I'd be impressed if you could get a Bosch one that goes up to 60 metres for that money.

Cheers,

Colin.

[dennis]

You don't if its a compass. You get a bearing on the object.. walk at 90 degrees to that measuring the distance you walk.. stop when the bearing to the object is 45 degrees different.. you have now walked the same distance as it was to the object at the starting place.

Its just a 45,45,90 degree triangle and both the sides are the same distance.

[Brian Gaff]

Why not just fire the missile and have done with it.. Sorry could not resist it. It sounds like you don't want the owners of object to know you measured it.

Brian

[Giss]

I would use a measuring wheel.

[Weatherlawyer]

A canon made of black powder? This is Do It yourself not Do Yourself In.

[polygonum]

Nor Photograph It Yourself.