Fieldcraft Effect of Fog on Laser Rangefinders

[Bushmaster7]

Did a search back to two years and nothing came up on this topic, so thought I would ask about the effects of fog on Laser Rangefinders. Just got a pair of Bushnell YardagePro range finding binos, and had some fairly heavy fog this morning. Just wanted to see what would happen and as I figured I could not get any decent readings out of the rangefinder. I assumed this would be the case given the physics behind it; but in your experience are there any of the better laser rangefinders that can penetrate and operate in fog? Maybe its partly a function of my just have a cheap setup. regards, Dale.

 

[Advokaten]

Re: Effect of Fog on Laser Rangefinders

It´s not just your RF that shuts down in rain/fog/snow,

they all do, just at varying degrees,

in short it is all about that beam of light that is sent out and how sensitive the recieving part is in the optics.

Bigger and better means more expensive and the RF on the Leo II tanks they had when I did my service the still ranged 3 km or 2 miles in total white out fog, needles to say in that sort of weather who cares what you can range, if you cant see it, how can you shoot it.

Best regards Chris

 

[McCrazy]

Re: Effect of Fog on Laser Rangefinders

+1 to Swedish Guy. I tried using my LRF (Leica CRF) last weekend in the morning when it was foggy and my range was drastically reduced. Once the fog cleared up I was ranging out to 1,000 yards no problem.

The laser on store-bought LRFs is a drop in the bucket compared to the wattage on a main battle tank. Doesn't take much interference to make the signal too weak to get to the target and return to the unit.

 

[Bushmaster7]

Re: Effect of Fog on Laser Rangefinders

Thanks Guys. That's what I thought. Are there any commercial LRFs that are better in terms of having enough power/sensitivity to at least cut through some fogs in which shapes are still discernable through a scope? That's the kind that was messing me up this morning, not a total white out type fog. If a Leica CRF was also significantly effected; albiet in heavy fog, sounds like unless you have a military grade unit that your out of luck when it comes to fog with most commercial type LRFs?? regards, Dale.

 

[The King]

Re: Effect of Fog on Laser Rangefinders

fixed installation LRF's are pretty much all that will do it.

Or - to put it another way - if it IS eyesafe it probably won't work. A MBT LRF could probably flash cook a squirrel at 1km.

Best bet - learn mil ranging. A laser only works 70-80% anyway. As well, you need to be VERY aware of backstop issues on foggy days. You may see what you are shooting at but not be in a good shoot situation because you can't see far enough behind.

 

[Bigwheels]

Re: Effect of Fog on Laser Rangefinders

I have both a Swaro, & a Lupy LRF, & I use the Lupy for hunting, & the swaro for everything else. The Swaro will read 13yds with just the slightest bit of fog, or rain, but will range to 2K otherwise. The Lupy will rnge in the fog pretty well, but it won't range anything past 800yds.

 

[softcock]

Re: Effect of Fog on Laser Rangefinders

You would be surprised just how little amount of water droplets in the air to just White-out a IR light source just like driving headlights or using your NV IR supplement in the fog.
I think I stated this once in a past post on LRF's before but I got a 10 year+ older Bushnell 600 yrd. LRF with the Mode settings like ( scan, rain, Refl, zip ) .
OK In ' Very Light fog ' my Leica 1200 takes a big dump & will spitout an IR pulse that can Not get reflected back for a reading, but the old Bushnell 600 on the Rain mode will get me out to 400 plus a little for ranging.
Don't know what is different in the old Bushnell's LFR circuitry on the (rain mode) setting but it works great.
.

 

[blksno]

Re: Effect of Fog on Laser Rangefinders

I believe most RF now days have a rain/fog setting on them, check your documentation. It may not be perfect for getting a deer ranged at 1k, but its better than nothing.

My Bushnell Elite 1500 for rifle and my Leupold RX-IV for archery both have this option. However, in whiteout fog, your SOL, but if you can see naked eye, you should be able to range it with the right settings.

 

[deersniper]

Re: Effect of Fog on Laser Rangefinders

I also have a leica 1200 and I don't think it has a rain setting. For the money it should have that and it should fix the range for angle.

-dan

 

[Bigwheels]

Re: Effect of Fog on Laser Rangefinders

During this last elk season I ranged a tree on the other side of the canyon where an elk trail was, & it read 350 yds+/- in some light fog. The next day in the clear it said 425+/- to the same tree. That was my Lupy RB800. My Swaro would have read 13, or 15 yds. It always does in the fog.