Thermal humidity temperature and dew point image quality

Discussion in 'Night Vision/Thermal' started by theblakester, Mar 17, 2021.

  1. theblakester

    theblakester Got a black belt in keeping it real. LSB TURKEY BUZZARD PRESERVATION SOCIETY SUS VENATOR CLUB LoneStarBoars Supporter

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    Hey guys, I’m looking for some numbers in regards to relative thermal image quality. I know high humidity and fog degrade thermal image quality, but can anyone give me some numbers that that will help predict thermal performance before a hunt? For example, X temp, with X humidity, And X dew point will yield good or bad thermal image quality. Or at X humidity and X dew point you will start to see a noticeable decrease in quality of image. Also, how much does dew point play into the image quality equation relative to humidity and temp? Hopefully I explained what I’m askin ok.. thanks in advance!
     
  2. pruhdlr

    pruhdlr Cantonment,Fla. SUS VENATOR CLUB

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    Watching this also.
    Have learned over my 8 years of using thermal,that it does degrade somewhat Especially after midnight.
    But how much is your and my questions. And is it predictable ?? ---- pruhdlr
     
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  3. theblakester

    theblakester Got a black belt in keeping it real. LSB TURKEY BUZZARD PRESERVATION SOCIETY SUS VENATOR CLUB LoneStarBoars Supporter

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    Just got done hunting a bit north of Nacogdoches— 10pm-4am, 45-50 degrees (40 windchill), 60-65% humidity, 10-20 mph gusty wind, and not sure about the dew point. Mostly clear skies.. got cloudy for an hour or so during the middle of the hunt. Thermal conditions were pretty good all night and stayed that way consistently.

    Recovered 3 btw. Not our best shooting. Should have been 5 confirmed plus a yote.
     
  4. pruhdlr

    pruhdlr Cantonment,Fla. SUS VENATOR CLUB

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    Our typical over here - -> peanut,cotton,and soy bean fields. Before or after harvest. Wind dies to 5kts or less about dark. Farm roads between a patchwork of fields. All combined we can see (line of sight) in most places 700-1100yds. Some fields are 50A+,usually square or rectangular.
    We are extremely low here. Only 50ft MAX above sea level. Colder night air sets in,dew point comes almost even with the temp. Night fog !! Thick mist,usually 85%+ humidity.
    Best viewing is in the winter weeks (NOT months). Relative humidity is lower. My hand held Pulsar with 12 micron core will see through it better than my 17 micron core older ATN.
    I look at the weather site before each hunting trip. We have a WX site only about 10 miles from our hunting area's. I tend to be mostly concerned with the humidity and dew point.
    Would be interested in you guys past expierances using thermal,under what conditions. --- pruhdlr
     
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  5. DeadPigs

    DeadPigs New Member

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    My issue is thermal “background”. Hunting on colder nights when the trees and grass have not been heated up all day is always best. On hot days, the trees and foliage will retain heat and reduce the contrast at night.
     
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  6. theblakester

    theblakester Got a black belt in keeping it real. LSB TURKEY BUZZARD PRESERVATION SOCIETY SUS VENATOR CLUB LoneStarBoars Supporter

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    Yeah I hunted a couple properties near rock springs for a while and the rocks on the ground would heat up during the day from the sun. I wound up stalking a few of them on more than one occasion
     

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