IR IMAGING DEVICE on the cheap

[HANKMARS]

I seriously desire to have an IR imaging device to use to observe circuitry when powered up so as to get hints of trouble spots. However, my desire to not spend $1K and up supersedes the former desire. I currently believe that an off the shelf $100 digital camera and the proper filters and a little hetrodyning could give me excellent results. Am I out of line here? A little overboard? Or can I construct a valuable tool for say $150?

 

[Harald Kapp]

My old digital camera "sees" infrared. Modern cameras often have built-in ir filters that block infrared. You may have to remove that filter which is a delicate operation (Google for tips).
Adding a new, ir transparent filte ris a must to block visible light. My old camera had become very insensitive with this setup requiring rather long exposures to get acceptable images.
If you have an old camera lying around give it a try. Do not be dissappointed if the results are less clear than expected.

 

[Alec_t]

Have you considered a cheap-ish night-vision security camera? (Not sure if they block normal daylight.)
These modules (or similar) are available with and without an IR filter. Perhaps use the difference between their outputs?

 

[HANKMARS]

My old digital camera "sees" infrared. Modern cameras often have built-in ir filters that block infrared. You may have to remove that filter which is a delicate operation (Google for tips).
Adding a new, ir transparent filte ris a must to block visible light. My old camera had become very insensitive with this setup requiring rather long exposures to get acceptable images.
If you have an old camera lying around give it a try. Do not be dissappointed if the results are less clear than expected.

Very interesting. My little Fuji digital may well be 10 years old. Not sure what you were considering old when you mentioned yours.A few years ago I took some shots of a lunar eclipse. For a hundred dollar camera, I found the results very impressive. Nowhere near quality for publishing but would even pick up crater images. When I had one of these lunar shots in an editor, I raised the exposure level, or maybe it was contrast, beyond any usefulness as far as the moon's image was concerned. But quite surprisingly, the stars came out. Millions. The camera had recorded the star images but was catering to my eyeball and the settings that I had programmed in. I believe I will not operate on my current camera but rather find a used camera or better yet buy a new low to mid range quality camera and experiment with it. I gather that any IR filter will be an independent piece. I wonder what the actual resolution of the photo chip or photo plate must be. Seems like it could be almost at an atomic level limited only by the size section that the electronics pull up as a pixel.

 

[HANKMARS]

Have you considered a cheap-ish night-vision security camera? (Not sure if they block normal daylight.)
These modules (or similar) are available with and without an IR filter. Perhaps use the difference between their outputs?

Good idea. I do have some spare security cameras on hand. Using them would solve the problem I have of getting a live feed from my camera to my computer as the camera goes to a transmit mode and live imaging stops when the communication cable is plugged into its port. Thx.

 

[Tha fios agaibh]

I've got an expensive Flir camera but alcohol works just as good for finding shorts on circuit boards.

 

[Bluejets]

I've seen some on Youtube use common old web cameras as well with a mod to remove the IR filter.
Some more difficult than others.

 

[Harald Kapp]

Not sure what you were considering old when you mentioned yours.

16 years...

I gather that any IR filter will be an independent piece.

Independent yes, but depending on the construction of the camera may be hard to remove. Care has to be taken not to destroy the sensor by this action.

The advantage of a dedicated IR camera is that it will display temperatures as false colors which makes it easy to identify hot spots. The proposed DIY solution will show only different levels of brightness.

 

[Harald Kapp]

The advantage of a dedicated IR camera is that it will display temperatures as false colors which makes it easy to identify hot spots. The proposed DIY solution will show only different levels of brightness.

You can use a palette (called ironbow) to map brightness levels to the more familiar color pattern.

 

[HANKMARS]

I've got an expensive Flir camera but alcohol works just as good for finding shorts on circuit boards.

It would seem that alcohol fumes could be unsafe in the presence of white hot metal or silicon.

 

[HANKMARS]

You can use a palette (called ironbow) to map brightness levels to the more familiar color pattern.

Any thots about constructing my own IR pass filter? I'm going to guess that an inexpensive IR pass filter would make constructing my own filter, seem to be cost ineffective. That is however, just a WAG.

 

[Harald Kapp]

Any thots about constructing my own IR pass filter?

Try this article.

 

[Tha fios agaibh]

It would seem that alcohol fumes could be unsafe in the presence of white hot metal or silicon.

It's a common technique to apply isopropyl alcohol while briefly applying power.

Look at 2 min into this youtube video.

 

[Alec_t]

Any thots about constructing my own IR pass filter?

Use the IR window from a junk TV etc remote control?

 

[hevans1944]

I currently believe that an off the shelf $100 digital camera and the proper filters and a little hetrodyning could give me excellent results. Am I out of line here?

Very much out of line. Suggest you read up on thermal infrared cameras, which are mainly sensitive to IR radiation in the 8 to 14 μm wavelength range. Silicon-based visible imaging cameras only have a near-IR response that peaks at about 0.9 μm. FLIR Corporation makes a suitable imaging camera that sells for around $300. Try this page for starters and links to more information.

There may now be low-resolution, raw microbolometer, sensor arrays available, especially from Asian sources, but good luck trying to use them. I would want to see something on the order of 100 x 100 pixels or better before wasting any of my time on them.

Most black plastic, such as heavy-duty (thick) contractor bags, are transparent to infrared radiation. You will need either a germanium or zinc selenide lens to focus thermal IR images onto the sensor plane. Ordinary photographic lens are opaque to the range of wavelengths that you need to image.

 

[skenn_ie]

I would like to buy/build a thermal imaging camera for marine casualty searches, but I suspect that is a whole different ball game.

 

[hevans1944]

I would like to buy/build a thermal imaging camera for marine casualty searches, but I suspect that is a whole different ball game.

I suspect it is. Why do you think a thermal imaging camera would be of any use at all for marine casualty searches? Are you looking for living survivors above or below the water? If not living, then after a few hours exposure to the marine environment everything reaches the same temperature. A thermal imaging camera is "blind" to objects at the same temperature as their surroundings. Tell us what you are trying to do before concluding a thermal imaging camera is right for you.

 

[narkeleptk]

I seriously desire to have an IR imaging device to use to observe circuitry when powered up so as to get hints of trouble spots. However, my desire to not spend $1K and up supersedes the former desire. I currently believe that an off the shelf $100 digital camera and the proper filters and a little hetrodyning could give me excellent results. Am I out of line here? A little overboard? Or can I construct a valuable tool for say $150?

you can find Flir C2's on ebay for around $200 sometimes (used)
I got one awhile back but rarely ever use it as its not as useful as I thought it would be.

 

[Tha fios agaibh]

you can find Flir C2's on ebay for around $200 sometimes

The resolution of a C2 sucks (4800 pixels) to be of much use.

You need much higher resolution to see detail for electronics use.

Btw, If anyone is interested, I've got a Flir E4 upgraded software to E8 resolution (76,800 pixels) for sale at a fair price.

 

[narkeleptk]

The resolution of a C2 sucks (4800 pixels) to be of much use.

You need much higher resolution to see detail for electronics use.

Btw, If anyone is interested, I've got a Flir E4 upgraded software to E8 resolution (76,800 pixels) for sale at a fair price.

Its good for the price range op talked about and is in a nice small convenient unit. I see detail plenty good enough with it for repair work and considering how little I even use IR I don't think I could suggest something 10X over what the op was looking to spend.