1500 yrd range finders

[royinidaho]

Jeff,

Thanks for posting those beam sizes.

I've been running tests with my Leica 1200 LRF.

First for consistent longer range readings a steady rest is a must. I rigged up a unique holder for it on a Manfrotto type tripod. It adds several hundred yards to consistent readinge.

One test I run is to take a "center" reading then readings on all for adjacent sides of the sighting square. With the rest I have been able to range as much as 140 yards into the trees at distances over 900 yards.

Additionally I've learned a bit about what "reflective" means. I hung a 3X4 "white" board at my firing line in the back yard. Range goes a bit beyond 1K. The Leica wouldn't range the white board at all????

I turned the board around and had no trouble ranging off of the masonite side at about any distance????? Maybe the white side is too reflective and maybe directional??

[elkaholic]

Interesting! I think I would have to agree......

[LouBoyd]

Originally Posted by royinidaho

Jeff Additionally I've learned a bit about what "reflective" means. I hung a 3X4 "white" board at my firing line in the back yard. Range goes a bit beyond 1K. The Leica wouldn't range the white board at all????

I turned the board around and had no trouble ranging off of the masonite side at about any distance????? Maybe the white side is too reflective and maybe directional??

Visible light is in the wavelength range of of about 400 to 650 nanometers Most commercial low power laser range finders use lasers between 800 and 950 nanometers. (many are 905 nm). Just because a surface appears bright white in visible light has very little to do with how reflective it is at the wavelength of the laser. Even if you hang up a mirror you probably cant' range to it because the mirror is unlikely to be exactly perpendicular to the outgoing beam and the return beam will miss the receiver of the range finder. The best reflector for a laser range finder are the corner cube prisms used for surveying work. Another good reflector are the glass bead surfaced tapes or road sign materials. Glass beads aren't perfect retro-reflectors but they're better than a random matte surface.

Live tree leaves (broad leaf trees) are fairly good reflectors. They don't retro-reflect, but they are "white" in the 800-950 nm range. If you have a gen III image viewer available try looking at the landscape on a clear moonless night.. Things which look bright through the image intensifier will generally make good targets for range finders. Any gen 1, gen 2, or gen 3 viewer or ccd camera with an infrared illuminator will quickly find objects which are retro reflective in infrared light. A gen 3 pocket viewer with just it's unfocused IR LED shows up a 2" diameter surveyors retro-reflector at over a mile away.

[30-338]

Interesting data. Thanks! When ranging game at long distances, it always seems to me that we are ranging the area where the game is located and not the actual game itself. The units with the scan feature are somewhat helpful in this respect. If you just take into consideration size of beam divergence, then the smaller the better, theoretically. But despite this fact I have found that both the Swaros and the Zeiss give me better results.
I also have found that the steadier the better. I think this accounts for the fact that my hunting partner can sometimes range farther with his Leicas than I can when using his Geovid...his is a steadier hand. 30-338

[Broz]

Ranging the area around the game is all well and good ,, if the game is on a hillside. But where it screwed me was flat ground where the 6' circular beam at 1000 turned into a blanket that was picking up objects 50 yards in front and 50 yards behind the deer. This is where you get in trouble, at 1000 yards a 25 to 50 yard mis-range can easily be a 10 to 20 inch miss or leg blown off. This is why I am so atimate about only ranging the quarry.

[30-338]

I am with you and we certainly don't want to wound animals! I always hunt pigs which are fairly small and we hunt the foothills mostly. We try to shoot at 1000 yds or greater if we can, but will take what we get. (Like last week a pig ran out in front of me and stopped to say "hello" and I made a "tremendous shot" at a laser verified 30 yards!!! Yes, it's true!



Anyway, the beam divergence published at a 1000 yds. was ...

Leica 1200 CRF ........1 1/2' tall by 7 1/2' wide

Swarovski Laser guide........... 6' circle

Zeiss monocular.............. 6' tall by 12' wide

This means it is problematic to target the animal only,at that range, even if we could hold that steady...because the beam is larger than the game animal targeted. It would seem to me,( and this is purely hypothetical in my case) looking at that distance , that even with an elk at 1000 yds. a beam that size would be hitting some terrain around the animal. I cannot imagine how hard it would be in the flatlands! 30-338 Thanks for the insight!