I know this question sounds weird, but I am looking for some kind of lens or filter to blur the images taken by a thermal camera. I don't need to blur a specific part of an image, just a blur uniformly over the whole image is good enough. Is there any such kind of equipment available?

Added: Software solution to reduce image resolution is not preferred, as it is required that the raw image data taken by the camera to be blurred. It would be ok if there exists some kind of material, when placed in front of the lens, is able to blur the image taken by the thermal camera.

  • It may help if we understand why the simpler software method is a problem.
    – StephenG
    Dec 7 '15 at 10:27
  • Mainly it is about privacy and security issues, no matter how the image data is encrypted using software, the hacker can get the source image data from the hardware. Dec 8 '15 at 7:45
  • That's an extraordinary requirement. The closest I could suggest is that you (a) use security features in SD cards, which do include a basic level of encryption, and (b) that you buy a safe, as it is implicit that to do what you appear nervous of a hacker would require physical access to the device. Getting a device with no WiFi support would also be a good idea. But short of building your FLIR from scratch I do not see how you can get the extreme security you require.
    – StephenG
    Dec 8 '15 at 8:32
  • @StephenG Thank you for the suggestions, to be honest I am also quite shocked by the requirement which came from the client. Dec 8 '15 at 9:03
  • 2
    I still don't understand how this is a photography question in any way. What you're looking for is a sensor which returns a single value, that's just plain not a photograph except in the silliest possible definition.
    – mattdm
    Jan 6 '16 at 4:47

You could try a document pocket / protector / bag.

applying the punched pocket filter

Wikipedia says they can be produced of different plastics, mine seems to work perfectly for thermal radiation:



You could buy a difuse filter (depends if your camera can hold one) or just put some fingertips on the lens.

You also can put some transparent plastic bag on the top of the lens partially covering it. The bluryness will depend on how much you cover it.



In addition to the previous answer, if there are clear infrared-pass filters for the camera, you could roughen the surface of the glass with sandpaper. This can be done very uniformly and hence can also give the needed professional look of the hardware.
In here are some more ideas about what to use as filter material for infrared camera. Maybe they are not applicable to a solution to be sold to a client, but they hopefully give you a good start to come up with something that works for your client.
Where or how to get exposed, developed colour film to use as a filter for infrared photography?


Some photographers use various low-budget techniques to get blur effects without having to invest in blurring filters. One of these might work for your situation:

  1. You could use nylons or a thin silk scarf over the lens.

  2. Some photographers use gauze, but that's a pretty severe blur, and usually only used around the edges of the lens.

  3. When it's cold enough outside, I've often times just breathed on my lens, then waited until the fog dissipates enough for the right blur amount I'm looking for. Probably not a solution for you, but thought it worth mentioning.

  4. Use a clear plastic bag covered with a thin layer of Vaseline on it. I'm guessing this would be your best option short of a specific blurring filter.

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