ToughButterCup Posted April 23, 2017 Share Posted April 23, 2017 OK, I've had enough. How on earth does anyone aim their laser measure if the distance to be measured exceeds - say- two meters or so? I attach the measure to a diddy (a few centimeters) camera tripod, the measure has an in-built spirit level. The stated range is 70 feet, and I was trying to check something 13 feet away. The laser is about a strong as a candle on the top of Mount Everest: the cat had great fun chasing the spot. That was the only way I had an inkling where the spot pointed. Have I bought a Frolicat laser toy, not a measure? (Image url, permsion requested) Link to comment Share on other sites More sharing options...
Onoff Posted April 23, 2017 Share Posted April 23, 2017 You need to see the world through rose tinted spectacles! Link to comment Share on other sites More sharing options...
PeterW Posted April 23, 2017 Share Posted April 23, 2017 Laser target and an overcast day ... Link to comment Share on other sites More sharing options...
Vijay Posted April 23, 2017 Share Posted April 23, 2017 Had this exact issue and found that shining the laser dot onto a flat red surface was the way to go as the dot will show up a hell of a lot better Link to comment Share on other sites More sharing options...
Brickie Posted April 23, 2017 Share Posted April 23, 2017 The reflective strip on hi-vis vests & a nice overcast morning is the perfect combo. Link to comment Share on other sites More sharing options...
Vijay Posted April 23, 2017 Share Posted April 23, 2017 Would the hi-viz strip effect the actual measurement at all? Link to comment Share on other sites More sharing options...
jack Posted April 23, 2017 Share Posted April 23, 2017 These things work, I believe, by running a match filter on a code output by the laser, and adjusting a time offset until the match filter confirms it's locked. The distance is worked out from the time offset (=the round trip delay) needed to get the match. The high viz won't affect the round trip delay. Link to comment Share on other sites More sharing options...
TerryE Posted April 23, 2017 Share Posted April 23, 2017 Ian, dusk is the best time to use a laser measure outside, IMO. Just enough light to see comfortably but low enough so that you get good S/N on your ranging and you can see the dot. I have a simple pistol grip with back aperture site and stick with a front sight and that I can register my Bosch into. A bit like aiming a rifle. The laser dot is just above the front sight from the back, so I know exactly where to look. You can see it once you've registered it. It's finding the bloody thing in the first place that's a problem. Link to comment Share on other sites More sharing options...
ToughButterCup Posted April 23, 2017 Author Share Posted April 23, 2017 2 hours ago, TerryE said: [...] It's finding the bloody thing in the first place that's a problem. Got it in one. Link to comment Share on other sites More sharing options...
Ferdinand Posted April 23, 2017 Share Posted April 23, 2017 (edited) 3 hours ago, recoveringacademic said: Got it in one. @recoveringacademic et al. The technique I was taught was to shine the spot at the ground by your feet, then gradually moving it towards the thing you are measuring while watching the spot. THen it is easier to track since you never lose registration. I have the green Bosch and it is OK for medium distances. Beyond that it is a target or glasses - have not tried sunglasses. Will see if my reactolites in my normal glasses help. As for being horizontal I judge it by the distance up the target from the ground. There is a huge tolerance on the level ness of the beam before the distance you are measuring changes materially. So no need to worry about a few inches or feet of wobbling as long as you get a reading off the right thing. Being 100mm out vertically with the spot at a distance of 10m only alters the measured distance length by 0.4mm. 300mm of inaccuracy in height means 1.2mm out on length. Being 100mm out vertically with the spot at a distance of 5m only alters the measured length by 1mm. Both are less than the roughness on the face of the brick you are probably holding the measure against and acceptable unless I have my trig in a twist. (Can someone who's laser measure is not lost in space give me a real world check on that last point. There is something counterintuitive about it. But I guess the existence of 7 x 24 x 25 as a Pythagorean Triplet means that if you measure length diagonally across a 7 x 24m garden by mistake after too many cocktails you will only be out by 4% or 1m on length which is more accurate than the General Boundary rule applied to your fence.) Ferdinand Edited April 23, 2017 by Ferdinand Link to comment Share on other sites More sharing options...
Onoff Posted April 24, 2017 Share Posted April 24, 2017 Surely just follow where the cat's looking? Or strap a laser pointer to it's head! (Mods, can we have an "I'll get my coat!" emoticon please?) Link to comment Share on other sites More sharing options...
Nickfromwales Posted April 24, 2017 Share Posted April 24, 2017 @recoveringacademic Ian, I've a red ( plastic ) laser finder doodaa in my Bosch kit I can post you if you want a lend? Link to comment Share on other sites More sharing options...
Nickfromwales Posted April 24, 2017 Share Posted April 24, 2017 Oh, also are you a million % sure your wind and vibration free at the laser, as even a guff will cause the laser dot to oscillate and be undetectable. Link to comment Share on other sites More sharing options...
PeterW Posted April 24, 2017 Share Posted April 24, 2017 +1 to what @Nickfromwales said I've got one of these and we set out about 15m on a sunny day with an ordintary Bosch rotary level. Draper Expert 22127 Prolaser Laser Target https://www.amazon.co.uk/dp/B00881OKHC/ref=cm_sw_r_cp_api_7gA.yb9WCXRBW Link to comment Share on other sites More sharing options...
Nickfromwales Posted April 24, 2017 Share Posted April 24, 2017 Yup. Ian, I don't use mine so you can keep it until your done with it if you don't want to buy one. Edit : the one peter posted may be cheap enough to get the expenses past Westminster. Link to comment Share on other sites More sharing options...
ToughButterCup Posted April 24, 2017 Author Share Posted April 24, 2017 Thanks all. The 30' fibre tape measure arrived yesterday. So comforting, so easy, so normal. Took it apart, painted half of it red so that thieving children (also self-builders) can't nick it, and then put it back together again. It's on the mantelpiece looking lovely, restful, dependable, boring. What's not to like? Link to comment Share on other sites More sharing options...
Nickfromwales Posted April 24, 2017 Share Posted April 24, 2017 3 hours ago, Onoff said: (Mods, can we have an "I'll get my coat!" emoticon please?) You've already used our 2017 quota ! Link to comment Share on other sites More sharing options...
Ferdinand Posted April 24, 2017 Share Posted April 24, 2017 A couple of old photographer tricks can be helpful for stability.. 1 - Is a normal monopod, which fixes the Laser Measure in one dimension. 2 - The other is a loop of string called a String Tripod. Put one end under your foot and attach the other to the measure. Does the same thing. A posh string tripod with have a thumbscrew fitting into the tripod socket on it. F Link to comment Share on other sites More sharing options...
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