Theodolite phone apps - has anybody used them?

bjornkn

Sorry to hear that! I was looking forward to hear your experiences with that project.
Have you done any tests with your iPhone theodolite and the distance laser too?

Roger

@bjornkn said:

Sorry to hear that! I was looking forward to hear your experiences with that project.
Have you done any tests with your iPhone theodolite and the distance laser too?

A couple points of interest. For long distance work with lasers in bright sun I have found some interesting aids. Red laser enhancement glasses are useful. Also red and light blue postIt notes make good laser targets. The light blue is kind or counter intuitive but the laser light coming off it is intense enough to see, but if you are wearing the laser enhancement glasses it will pass the reflected red light while knocking down the color intensity of the blue background. The increased contrast will help you see the target spot.

Also you can fold the postIt to make a shade flap to increase contrast in bright sun.

Roger

(WARNING/DISCLAIMER - techniques described here could blind you. I do not recommend that anyone try this. The following is for information only)
Laser rangefinders are somewhere between difficult and impossible to use in bright sun. The first thing to do is get red laser enhancement glasses. The red lenses attenuate all but the red wavelengths in light. So your red laser dot will look brighter than all other light with non-red components. But laser dots are quite small and becomes quickly hard to find as distance increases. By attaching my Bosch distance finder to a monocular with a red filter (25A photographic filter) the problem is entirely solved.

The only problem is having the laser beam returned to your eye by a shiny surface. Before engaging the laser I use my monocular to scan my target for highly reflective shiny surfaces. Once I am sure the problem does not exist I engage the laser and get a distance reading. Worst case like a mirrored wall, I would have to tape up a paper target. Or just close my eyes just before turning on the laser.

From a practical standpoint there is no problem, but accidents do happen so awareness and an abundance of caution are called for. Next I will need to SketchUp a more permanent rig to attach distance meter to monocular.