Electronic Rangefinder

[Blue Monkey]

I've got some old Agfa folders and a few other cameras that require you to set the focusing distance manually (No direct focusing through the camera viewfinder).

Long distances are pretty easy to configure for hyperfocal focusing, especially with smaller apertures. Close focusing with wide apertures gets tricky - especially if some camera are metric and some imperial (having to remeber which is which). I was looking at getting the optical hotshoe mounted rangefinder, but I would need one of each and besides being pricey, I hear their prone to going out of alignment. Plus the tiny little windows are a pain to use with eye glasses on.

I came across this at Canadian Tire today ($8.99 on sale!) Other may find it handy to for rangefinding.

According to the specs, its good 1-32' (0.3-10m) = or - 0.5%. Has a laser targeter, but is ultrasonic for measuring. The thing is very small (2") and pocketable.

So far, it is accurate for targeting big objects. Not so much for tiny small objects. The measurements are consistant so far. Its easily switchable between metric and imperial.

The stores in Ontario have it on sale this week if you could use it too. Can't argue with the price.

Bharat.

 

[Ralph Javins]

Good morning, Bharat;

Nice idea. Thank you. I do have an old Ideal Range Finder made years ago by the Federal Instrument Corporation on Lon Gisland City, New York, that I pull out of its burgandy colored cardboard box every once in a while. It is an optical coincidence device. It is rated to go from 2.5 feet to 100 feet. Your idea of a modern electronic equivalent would have an advantage in very low light or even darkness for very long duration shots.

 

[MattKing]

That's a good deal - their website has it at regular price at $22.99:

http://www.canadiantire.ca/AST/browse/6/Tools/MeasuringTools/EstimatorsCalculators/PRD~0574552P/Mastercraft%2BMaximum%2BMeasuring%252BLaser%2BPointer.jsp

Matt

 

[AgX]

Without any electronics and optics one can still do some distance measuring via triangulation just using a stretched arm and a card held in your hand or even just your fingers...

 

[Q.G.]

Such ultrasound rangefinders are not pleasant thingies when they point one at you. The rhythmic pulse, though perhaps not audible, certainly lets itself be known inside your head.
Optical rangefinders are cheap too.

 

[apconan]

Without any electronics and optics one can still do some distance measuring via triangulation just using a stretched arm and a card held in your hand or even just your fingers...

can you elaborate on that?

 

[DWThomas]

can you elaborate on that?

I believe this is the idea AgX is talking about. A calling card rangefinder.

It does proportions using your left and right eye as a base line instead of lenses and prisms. I've not (yet) tried making one, but I would expect it to be a little bit better than guessing.

I thought I had seen another website with directions and an easier to read presentation, but haven't been able to find it.

 

[AgX]

Yes, one can either use a card calibrated by oneself with distance marks like a ruler, or just use ones knuckles, straight fingers, an abducted thumb, etc... and memorize what distances they indicate.

One stretches the left arm holding that card in ones left hand and via ones left eye alines the left corner of that card with the object. Then one looks via ones right eye to the object and reads the distance mark at the card's upper edge where the object is seen now. By "flipping" between eyes one can control the right position of that card.
Seems complicated? Just give it a try with your knuckles and you'll understand.