Hate to ask what's probably a stupid question, but here goes.

I know firefighters will use thermal imagers for various uses all the time, but not knowing if the equipment they use is designed differently for that purpose....is it safe to point any old thermal imager (in my case a FLIR Breach) toward a fire?

Thanks

Not a problem. FLIR has tech to protect from solar radiation so a fire won't phase it.  I've viewed camp fires through my B60 many times.

Sounds good, thanks.

I've flashed a ThermApp by fires before with no ill-effects, so I knew it wouldn't be an immediate detriment, just didn't know if it may have a negative cumulative effect.

If you really want to see something cool, review a post-fire area with a Gen1 scope... it makes quite a difference due to the difference in dynamic range and linear signal amplification.

It's something a Gen2 or Gen3 can't do, but Gen1 is great for spotting underground thermal vents and hot spots that are throwing out embers or still burning.

I looked at a fire once with a thermal and it left a streak almost like if you look at a bright light with NV....a few nucs and it was gone.

The other night I looked at my fire pit with my breach a few hours after we had a fire...it was about 39 degrees out...and I could see a perfect dome above and around the fire pit.  I need to check and see if I took a pic.

The sun is another story though...most thermal can get damaged by directly looking at the sun right?

Most thermal design includes camera use - and many fixed cameras include one period, per day, when they are looking directly at the sun for an extended period.

So most thermals are designed to handle the sun just fine for as long as you want.

David.

Just read interesting article about flir sensors and the several ways they design so they are not harmed by the sun.  Even so, in the Flir Breach manual it says don't point at sun and says inadvertent sun damage not covered by warranty...prob more of a cover their asses kind of thing I am guessing.

Some other kinds of sensors not always the same though and sun can destroy them...

https://www.ifsecglobal.com/are-thermal-cameras-damaged-by-solar-radiation/

"Vanadium Oxide is just one material that is used for manufacturing these detectors. Other materials are Amorphous Silicon (a-Si) and Barium Strontium Titanate (BST). Manufacturers using a-Si or BST technology are sometimes even specifying in their own user manuals that the cameras cannot be exposed to direct sunlight. Otherwise the camera will be permanently damaged and warranty will be void."

For some reason I swore the literature with my IR Reap warned about pointing at sun...even of it was off....but I just looked thru quick reference and full manual and can not find anything about the sun..must have been reading something else.  My thought was even if it's off...the lens can still focus the sun's raise/energy and create heat and damage electronics and internal parts.  Kinda like a magnifier glass and burning ants....and I wrong?  Please someone smarter then I school me on this please.

My Pulsar manual says not to use it to view the sun.

Someone make a thermal video of the sun and posted here please

Thermal cameras are typically calibrated for imaging different ranges of temperatures. They usually have Low, High, and maybe Auto modes.  Cameras built for firefighting applications typically operate in Low Gain mode.  This basically reduces the sensitivity of the sensor but prevents the image from saturating.  It's like wearing sunglasses on a bright sunny day.  The Breach and PTS operate in High gain mode, which produces a higher sensitivity image.  If a high intensity object like a campfire is imaged in High Gain mode, the pixels imaging the fire will most likely saturate and detail will be lost.  It will not, however, hurt the camera.  Even imaging the sun, which is definitely not recommended, shouldn't permanently hurt the sensor.  I have accidentally done this on a couple of my Tau-based thermals over the years.  The damage only lasted a few minutes and the system was fine after a number of NUC cycles.

FLIR Marine Thermals are used all the time during the day in the ocean with no ill effects.

Can FLIR uncooled VOx cameras be pointed at the sun?

Special infrared-transparent windows are used on the sensor packages which filter out infrared radiation at wavelengths below 7.0 microns. This makes FLIR's thermal cameras less susceptible.

The spectral response of the microbolometer is influenced by all of the optical interfaces between the focal plane array and the scene or object being imaged. These include the sensor vacuum package front window, the lens, any protective window in front of the lens, and the atmospheric transmission between the object and the camera. FLIR's standard sensor packages have front windows that define the short wavelength cut-off of 7.5µ, while the bolometer itself defines the long wavelength cut-off of 13.5µ, assuming negligible atmospheric attenuation.

Although FLIR does not recommend intentionally viewing the sun with a FLIR uncooled camera, looking at the sun will not permanently damage the sensor, but it may take some time for the camera to recover. The amount of time needed for recovery depends on how long the camera is exposed to the sun. The longer the exposure, the longer the recovery time needed. A flat-field correction (FFC) will help reduce image artifacts caused by imaging the sun.  FLIR does not recommend exposing the camera to laser sources.

One other thing to consider - Most thermals operate at around 8-12 microns, and most of the sun's output is at 0.5 microns. There's not much thermal output in terms of raw energy, so focusing the 8nm and longer wavelengths isn't going to put as much energy into the sensor as a visible-light camera would get when looking at the sun.

On top of this, most of the visible light is absorbed or reflected by the lenses, and what does get through is going to be very out of focus.

All of these factors make a thermal far less likely to have as much energy focused on the sensor as SWIR, NIR and Visible cameras.

Great info thank you!!

I own some cameras- and a Therm-App of mine once looked at a reflection of the Sun apparently at a glimpse in my car, because when i next looked at it it had a bright streak on it(to this day I don't know if it was actually the sun that caused this, as thermal doesnt go through glass....)- it took far longer than you'd EVER guess for that to 'fully'dissipate - months(left a bright streak which became a clear streak which then completely dissapeared)
That was a odd case.

But the therm-apps are funny- I once looked at a toaster with it, and then when i looked away, i saw minor streaking from it- and i know for sure it was the toaster, this time- that went away very fast.

So, it's hard to tell- but intense IR sources will overcharge the camera a little bit, and NUCs don't fully get rid of it- time does though.

Meanwhile my Pathfindir II , is built for sun exposure, (plus it's one of FLIR's Vanadium oxide sensors)- and if you drive into the sun, (I turn it off when possible to avoid this), it'll be fine- but if you keep going into the sun, when you finally turn away, it'll have bright spots/streaks also(not like the therm-app did), although a few NUC's will clear it.

Fun fact: when shooting videos, i've looked at the low hanging sun with my therm-app- the Sun did not affect it at all then , so I suspect if it's high noon, you're in trouble- but if its sunrise or sunset, it's the same as with our eyes- it's safe immediately when the sun is coming up or down