Public Lab Research note


Canon A2200 NIR conversion

by nedhorning | September 25, 2012 14:08 25 Sep 14:08 | #4002 | #4002

Canon A2200 NIR conversion

This past weekend during LEAFFEST, under the watchful eye of Jeff Warren, I converted a Canon A2200 camera to capture near infrared (NIR) images using a technique similar to the video Jeff Warren did for the Canon A490. The A2200 has a good review by a company that does professional NIR conversions. Some nice features are that it has a custom white-balance option (can provide images without the strong bluish hue common with many converted cameras) and it does not have a hot spot (bright spot on the image) which is a problem with some camera models. There is not a final release of CHDK for the A2200 but I've been using the beta release and have not had any problems with basic functionality. The firmware is recent enough to be able to handle SD cards larger than 4GB without any special (and cumbersome) formating. Another feature that someone else highlighted is that it uses the older (and more common) 4-pin USB port for data and CHDK communication and a 3.5 mm stereo audio plug for video output. Some newer Canon cameras use an 11 pin USB for video and data. Some other good features are that it's small, light and takes decent photos.

Below is a short guide intended to help someone interested in this conversion. Before trying a conversion I suggest that you look at Jeff's video to get a good introduction to the whole process. It's important to work in a clean environment to avoid getting dust in the camera. It's also good to keep the screws in a container or on a piece of tape so you don't loose them and keep them organized so you can put them back in the proper holes when you reassemble the camera. When unscrewing the screws make sure the screw driver (all screws have a phillips head) fits nicely in the head of the screw or you risk stripping the head.

If you have comments about how to make this a more useful guide please let me know. In a few weeks I'll post a comparison of different NIR converted cameras including a couple that were professionally converted.

The first step is to remove the back part of the camera case. Remove the four screws as noted on the figure below. Once the screws are out try to pry the back part of the case off with a thin flathead screwdriver or something similar. The case on my camera had a tight fit but after moving the screwdriver around a few times it popped off.

Remove the four screws that attach the display screen to the camera body then gently (you don't want to tear the brownish cable) move the display out of the way of the sensor circuitry.

Remove the three screws that attach the sensor circuitry (mounted on an aluminum plate). This takes a little work since there is a drop of hot-glue on each screw. Using moderate down-pressure on the screw and a good fitting screwdriver the hot-glue popped off as I was unscrewing the screws. You might be able to pry/pop off the glue with a small flathead screwdriver before unscrewing the screws. After the screws are removed gently pry it up and out of the way so you can access the rubber gasket under the sensor. You do not need to unsnap the wire harness connected to the sensor circuitry, just move it out of the way. As I was lifting the sensor circuitry I broke one of the plastic posts that help guide the sensor circuitry into place. I don't expect that's a significant problem but something to try and avoid. Do not put your fingers on the sensor or the hot mirror.

With the sensor circuitry out of the way you will be able to remove the rubber gasket that secures the hot mirror over the camera's optics. You can use a pair of tweezers to carefully pull the gasket up and out. The gasket does not appear to be all that strong so carefully working around the gasket seems wise. Once the gasket is out the hot mirror should be loose. It might fall out just by turning the camera over or you might need to gently pry it a bit. It's a good idea to save the hot mirror without putting finger prints on it in case you want to put it back in the camera at some point.

The next step is to place the developed film cut to match the size of the hot mirror into the same place the hot mirror was housed. Once that is done the camera can be reassembled. Putting the sensor circuitry plate back took a little coaxing since the remaining hot glue pieces got in the way. I pried the hot glue off with a flathead screwdriver to make more room. The other reassembly steps were straightforward.


18 Comments

Hey, thanks for posting this! I've been wanting to convert a camera to take IR pictures for a while now. I tried to open up an old Fuji Z series I don't use anymore, but the IR filter wasn't accessible. I'm looking forward to hearing your evaluation of different cameras and their possibility for conversion to IR.

The only thing I'd add: I did some research across the internet on making a filter that only lets IR pass and blocks visible light. You mentioned using developed film as the filter, which is what I did as well. However, about half the sources I found said to develop exposed film, the other half said unexposed. I choose unexposed, and it was the wrong choice ;). So, in your guide it might be worth mentioning that the film needs to be exposed, then developed.

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I thought the film I used was developed unexposed negative film but am not certain. I got the film from Jeff Warren so maybe he can clarify. There was a recent post comparing different film types for NIR filters: http://publiclaboratory.org/notes/cindyexcites/9-20-2012/infrared-camera-test-film-types. It would be great to test different filter material.

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Wow! That is cool! I was always envy to people has a skills to open-up such devises :)

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I just removed the IR blocking filter from a black Canon A1300. Virtually the same procedure applied as with the A2200 mentioned above. I didn't put in the developed film though, because I'm not too happy about the amount of visible light that still gets through that. I think I'll glue a mount ring for astronomical oculars onto the front of the lens housing so I can screw on all kinds of filters. I'll get me a very deep red glass filter for NIR. I'm going to mount the black A1300 on a bar beside a silver unmodified A1300 so I can take two shots at the same time. Should be fun :-)

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I did this conversion. Everything went as above, except that the glue holding the sensor in place is most definitely NOT hot glue. It wouldn't melt even with a soldering iron set to 650 deg F. It does break apart very easily under pressure with a very small screwdriver. This produces many little particles, but the can be collected by using transparent tape and the screwdriver to get the tape into the narrow spots. The glue is not just on the screws for the sensor board, but also around the corner of the board itself. You must clear the glue from a path around the edge of the board. A little bit of pressure under the board will pop the corner loose. Do not try to lift the sensor board all in one shot; that will probably break the pins as mentioned above. Once the sensor board is loose, it can be lifted up.

As for questions on exposed or unexposed film, it depends on whether the film is color print or color slide film. Exposed slide film turns clear, so use unexposed. Exposed print film turns dark (to make those areas light during printing), so use exposed.

Or do what I did and buy an inexpensive 87 filter. LEE Filters makes an infrared filter from polyester film that works just fine and is much cheaper than Kodak Wratten 87. It comes in 3" or 4" squares, but you only need about 1/2 x 3/4 inches, so you might ask around to see if anyone has extra. See: http://www.bhphotovideo.com/c/search?Ntt=lee+infrared+87&N=0&InitialSearch=yes&sts=ma&Top+Nav-Search=

(I just checked B&H Photo, and they are out of stock, so look around, or check in every so often to see if they are in.)

No light gets through this filter, so images are purple in color. I have my camera set to B&W, which is easier on the eyes.

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Hi! very cool project. does anyone know what the maximum wavelength that can be detected using a converted camera?

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Hi, Hayden - late reply, but it's around 1000-1100nm.

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I just completed this conversion, and the image on the cameras LCD screen looks good, but the camera will not take pictures. Occasionally it displays the focus box with yellow exclamation. Is there a setting I need to enable so the camera will ignore the fact that the glass filter is gone?

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Hi Roolark - Make sure you didn't disconnect or tear one of those thin ribbon cables. That's the only thing I can thing of that would cause that problem. If the cable is damaged you could contact Chris Fastie who was able to order replacements for $11 to repair to damaged ones I gave him.

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Roolark, There must be a loose or broken connection. You probably should open it up again and check for that and wiggle everything and see if it works. If not, a trace in a ribbon cable could be severed. Some of those cables are easy to buy on eBay.

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I just followed these instructions and converted an A2200 -- thanks!

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Forgot to mention: There are IR pass filters to be had specifically for this type of camera. They come with glue buds and they fit perfectly on the front of the camera. They are also a lot cheaper than the professional threaded filters.

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Do you have a link for those IR filters?

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Took me a while to find the URL again: http://www.angelsghosts.com/store/viewitem.php?productid=16

I think the price has gone up a bit, I paid just below $20 when I ordered a year ago.

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Thanks for the link. For my ghost hunting, I have been buying PowerShot A590s for $20-$40, plus a $5 filter tube that snaps on, plus an $8 IR filter. The A590 is a bit of a pain to convert, but results are pretty good. Here is a shot with that setup from today. There is one ghost turtle on the rock in the pond.

850nm-443-26.jpg

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Wow cool Chris. I wonder if we could design a 3d printed adaptor between the camera and a spectrometer.

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I guess it depends which camera and spectrometer you want to connect. A good approach might be to make a 3D printable Ebert. That could work with most PowerShots. The only tricky part is accommodating the retractable lens.

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Many thanks to Ned and the other conversion pioneers. On my second try I followed these instructions and successfully converted an A2200. On my first try I did not quite follow these instructions and may have a A2200-shaped brick--I'm handing it off to someone with better fine motor skills and more microelectronics experience to try for recovery. (I'm not worried, this is about the learning curve I expected) The following amplification on Ned's instructions may be useful to others: when you move the display out of the way of the sensor circuitry, be sure that you move the screen to the bottom of the camera exactly as pictured in Ned's "remove display screen" photo above. This can be accomplished by slightly lifting the screen to clear the tabs and then rotating counter clockwise about 45 degrees about the upper right corner of the screen assembly--just about where the small metal post is in Ned's photo. The reason for this is that there is ribbon cable just underneath the screen assembly at that corner that attaches to a connector on the circuit board underneath. If you move that corner too far you will pop the ribbon out of the connector and the camera will no longer work.

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