Hi, it's quite an easy and interesting project to convert an old digital camera to infra red. I've done it on a couple of old cameras. It involves removing the infra red stop filter that covers the sensor and adding a visible light stop filter over the lens using the filter thread. The last one I did cost me £15 on ebay.

Whilst converting a digital camera or indeed using a film camera and IR sensitive film will get you IR images they are nothing like what you get from a camera like the one in the video..just like this

This is my heat seeking camera (for want of a better description)

I use this a fair amount in my day job looking in electrical cabinets circuit boards and motors and pumps and bearings on large machinery

this ones about £900 or so as you can see it has 2 cameras one for visible and one for ir which are overlaid to make the heat image

This is an IR image taken with my Samsung WB500 converted to Infra Red.

Hi

I'd like to know how to do the conversion as well. What do we look for with the visible light blocker?

George

To convert a camera you disassemble it …remove a filter from the front of the sensor reassemble and then use a 720nm filter on the lens

lots of tutorials on YouTube for various cameras

i have done a few dslr’s but compacts are easier

Ah, I see the confusion. Yes, I was thinking of thermal imaging, not infra red photography.

I want something to look at the heat, (or cold), of machines, circuits and house walls and doors etc. There are some available but the cheaper ones have very low resolution – I need more detail than just a vague splodge. The good ones are very expensive, so am on the look out for a reasonable compromise.

Edited By John Doe 2 on 12/03/2023 11:41:16

This was one of our Lab bee hives last year. The bees look nice and snug.

regards Martin

It does indeed, as do the Topdon company, who seem to be very switched-on cookies, but who make reasonably priced goods; hundreds of pounds rather than thousands.

Just deciding whether to go for their iPhone plug-in thermal imaging camera or their stand-alone one.

Very impressive demonstration, Sam

MichaelG.

Firstly, The OP was about thermal imaging not IR. Thermal imaging relies on IR energy being emitted from an item due to it’s temperature. IR imaging detects IR energy from an external source (sun, filtered lamp, LED) being reflected from or absorbed by the surface of the item being imaged. Thias is the same as normal photography but at a wavelength “colour” we can’t see. Thermal imaging uses wavelengthes even further from the visible range.
You cannot convert a visual camera to a themal imager.

The maker of the video clearly does not understand how thermal imaging works. The reason for the hung up coats appearing hotter is due to their surface emission properties. If at the same temperature a pure black surface will emit more IR energy than polished metallic one. Thus the coats “look” hotter than the lighter wall behind them. You cannot accurately measure temperature using IR unless you know and compensate for the surface emissivity.
The thermal images in the video seem very sharp to me given the claimed resolution. Maybe the video has been processed.
Clearly there have been huge advances in technolgy but this is a imaging device not a measurement instument.  I’ve used most types of thermal cameras personally and professionally for about 30 years and IR for 40.

Photons are photons, and the difference between “thermal imaging” and “IR imaging” is mostly just semantics.

Normal digital cameras use silicon sensors, which are not capable of detecting wavelengths greater than around 1100 nm. That’s already well outside the range of human vision and hence could be called “infrared.”

Deeper IR cameras require different technologies, e.g. smaller band-gap semiconductors or bolometer (electrical thermometer) arrays, or even superconducting arrays. To image deep IR, you also need to cool the sensor, or else the ambient temperature will flood the image with noise. The Webb space telescope is an IR one, and enormous efforts were made to keep its sensors as cool as possible.

Nearly all digital cameras have an IR filter in front of the sensor array to block IR wavelengths. This is because glass bends light differently depending on the wavelength of the light, and lenses are generally designed to properly focus light in normal visual wavelengths. Since people don’t see in the infrared, allowing those wavelengths to be imaged too (at an incorrect focus point) will cause excessive blurriness.

Converting a digital camera to “IR” is done by removing the IR block filter (normally a very delicate operation), and then adding a very deep red – so deep it’s virtually black – filter in front of the lens to block all wavelengths that aren’t sub-visual.

Using an IR-modified digital camera is also a bit different. A traditional viewfinder would be virtually black and useless, though contemporary digital viewfinders or screens should still show something (likely dim or noisy). Long exposures are normally needed since so much less light is let through. Because the wavelength of the imaged light is longer, the imaging resolution is lower too, leading to a bit softer photos.

In the old days of film cameras, professional lenses were often marked with an IR focus offset. You would focus using a rangefinder (because the viewfinder would be black) and add an offset because the point of focus would now not be the same as with visual wavelengths. I’d expect that some modern per-pixel focus systems could handle this automatically if they are sensitive enough.

I’m not sure what those cheap IR imagers use, but based on the price, I’d expect they are just cheap, low resolution silicon sensors with an appropriate filter in front. By comparison, an IR-modified DSLR or mirrorless camera can produce stunningly beautiful and other-worldly photos.