Comment Re:Replace a $1 ruler with... "lasers" (Score 1) 78
I actually helped with some of the development of this product, so let me clear up a few questions:
You have to calibrate the laser dot spacing against a ruler anyway, so you don't save the cost or weight of carrying around a ruler.
The lasers are coaligned in their case and are calibrated at manufacture to be exactly one inch apart up to a distance of roughly 20 feet. Each unit is tested before it goes out the door.
The calibration is only good at ONE distance and perpendicular to the lasers
The lasers are one inch apart up to around 20 feet, at which point they start to spread. The laser scaling device is meant as a quick reference scale, not an exact scale of measurement for small items.
Rulers and tape measures can be used to measure other things, that lasers can't- like skew distances, or circumferences
Yes, but if you're taking thousands of pictures in one sitting, it sure does help if you don't have to place scales in every picture.
Rulers always show up as the right brightness on a photograph. Lasers have to be adjusted in brightness to match the scene, and may wash out if a flash is used
The laser doesn't work in every circumstance. Neither does a ruler, actually.
Red laser light is not too visible if the object is like, red, or covered with blood.
...and if you're in a crime scene that's covered in blood, it's not the best idea to charge through the room so you can place a scale next to evidence.
