Thermal Night Vision Cameras

[Gotcha Covered]

Has anyone had any experience with these cameras in spotting semi submerged logs at night, F.A.Ds, fishing nets or other semi floating hazards.

[Tkeeth]

night vision and thermal are two different technologies. night vision amplifies available light, thermal changes the wavelength to a visible spectrum. night vision may help you see whats in the water at the surface, thermal will not as it will be the same temp as the water

[Wotname]

Originally Posted by Tkeeth

night vision and thermal are two different technologies. night vision amplifies available light, thermal changes the wavelength to a visible spectrum. night vision may help you see whats in the water at the surface, thermal will not as it will be the same temp as the water

To be more accurate, thermal will distinguish between different temperatures; not all the objects in the water will be at the same temperature as the water. Objects that are at a different temperature to water (especially ones that are hotter) will show.

[Tkeeth]

let me be clearer then. as a level iii thermographer, 20 years experience--- water is not ir transparent. so unless its dry and sticking up, you will not see it. it would also have to have a heat source, such as solar heating, not at night, and have high thermal capacitance which logs and fish nets do not have. a container may, but as i said, would have to be high up and fairly dry.....

there are combined technologies that can aid you, but there is no 100% solution in this tech.

[Dymaxion]

Heat stored from the sun beating down on the top of a shipping container all day MAY help create enough temperature difference to spot it at night. Would depend on quality of the imaging system.

Night flights over desert minefields rely on the heat stored in the landmines to stand out against dry desert sand that cools rapidly once the sun sets. Betcha those imaging systems cost a tad more than the average sailboat however.

[Tkeeth]

Originally Posted by Dymaxion

Heat stored from the sun beating down on the top of a shipping container all day MAY help create enough temperature difference to spot it at night. Would depend on quality of the imaging system.

Night flights over desert minefields rely on the heat stored in the landmines to stand out against dry desert sand that cools rapidly once the sun sets. Betcha those imaging systems cost a tad more than the average sailboat however.

thats different tech still. those systems use pass bandwidth filtering to improve sensitivity and increase visibility in certain condtiins. if you were the operator of that system, you would note that it worked well just after dusk with dimishing effect after a few hours. the same would apply here.

[Dymaxion]

Friend struck a whale here in Bay of Fundy, Canada East coast. Glancing blow that took prop and shaft right out of the hull. Taking the OP's question as being on nighttime collision avoidance with floating objects.... could a low buck depth finder mounted near the bow and pointed forward at a shallow angle work? Apologize for thread hijack.

[Tkeeth]

they have forward sonar....i cant say how it works as mine never has.

[fatherchronica]

We take our handleld Flir everywhere with us. Whether it can see everything I do not know, but it sees a lot of stuff and clarifies sometimes weird radar images. Also it will tell you if that deserted looking 3rd World beach is really deserted when taking a moonlit stroll on it. Once we were camping and I could see wild poodles in our camp with it. Turned out they were foxes, but still I could see them. I bought mine refurbished from Flir 4 years ago, it is like new and I use it several times a month.

[Tkeeth]

Originally Posted by fatherchronica

We take our handleld Flir everywhere with us. Whether it can see everything I do not know, but it sees a lot of stuff and clarifies sometimes weird radar images. Also it will tell you if that deserted looking 3rd World beach is really deserted when taking a moonlit stroll on it. Once we were camping and I could see wild poodles in our camp with it. Turned out they were foxes, but still I could see them. I bought mine refurbished from Flir 4 years ago, it is like new and I use it several times a month.

good for you......seen any floating logs or fishnets or containers or whales as the post asks?

[fatherchronica]

I have seen porpoises at night under my bowsprit with the Flir. A common misconception found in The Good Book is that some large sea going mammals are fish. But it is not true. You can see whales and porpoises and otters and seals and I imagine walruses and dugongs with thermal imaging. Maybe you couldn't see a dead one at just the right moment, but I think when they started to decompose they would become visible again. There is a lot of ignorance on this subject out there caused by, probably, preconceived notions of what a person wants reality to be.

[fatherchronica]

Also, just sayin' ( A nod to S. Palin) there are two sides to a bed every morning, and hair removal kits available on Ebay. I think a person would need a mirror depending on where the hair was lodged.

[oleman]

The sonar on a navy warship is capable of detecting a floating log below the surface, also shipping containers well below the surface. Things that make noise are especially easy to detect. And a submarine many miles away.
I bring this up because these capabilities have been available for the passed 70 years. I would think cheaper designed small-craft sonar would be able to have some of these capabilities in 2017!

[Tkeeth]

Originally Posted by oleman

The sonar on a navy warship is capable of detecting a floating log below the surface, also shipping containers well below the surface. Things that make noise are especially easy to detect. And a submarine many miles away.
I bring this up because these capabilities have been available for the passed 70 years. I would think cheaper designed small-craft sonar would be able to have some of these capabilities in 2017!

a person who speaks about what they know! how novel!

[Tkeeth]

Forward-looking sonar: 5 units tested - Practical Boat Owner

seems a much more reliable option.