Frost On Fresnal Lens

gtk

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I've posted this question before, but here it goes again.

Back during bow season, I walked in front of my camera one morning going hunting.  The camera did not fire, and I was thinking it was because there was a heavy frost on the lens.

Now, the other morning, I was checking my cameras again.  I checked a camera, and it was covered with frost.  I walked right up to the camera, and it did not fire.  I waved my hand in front of it several times, and it did not fire.  Then, I blew my breath on the camera, and as it melted the frost, it took a pic ?

The camera works fine all other times.  Has anyone else noticed this problem, or have I done something unique here.
 



Archilochus

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Hi gtk,
The IR signal radiated by any warm body (or your hand) is very weak.  That's why the Fresnel lens itself is sooo thin - any thicker and it would block the signal from reaching the sensor element. Most regular plastics, glass, plexiglas, etc will block the signal.  Water or ice will also block the signal.
I've never had a Fresnel lens frost up (at least that I've seen) - but the frost would surely cause no pic to be taken if thick enough.

Archilochus
 

Stever

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yep, happens to me.No pics when frost. Heavy frost forced me to pull cameras for 3 days. I felt it wasnt worth leaving them out. It seems to be colder here now and I am using that desicant stuff so no frost last two weeks.
 

Stever

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For Frost issue my best luck so far has been to scrape off the frost rather than bringing inside thawing out. Seems frost stays off if you let cam stay frozen.
 

Passthru

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 Frost also settles onto objects,you may put a hood over the lenses of your PIR and camers.notice that when there is a frost anything that is covered will not have frost on it.
 

Stever

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frost on one of my cams formed on the inside of the case. Desicant should solve that problem.
 


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