IR-modified Canon PowerShot S3IS

UPDATE (December 2015): After many years of productive use (2009 to 2014), the digital camera featured in this page has developed problems and has now stopped working. Further development regarding this project is no longer possible.

The modification involves physically removing the “hot plate”, a kind of filter that blocks infrared light. Manufacturers install it in cameras in order to correct for the reddish hue inherent to CCD or CMOS sensors. Removing such filter makes the camera more sensitive to IR and as well as H-alpha wavelengths, which is particularly useful in deep-sky photography.

Modified Canon PowerShot S3IS camera

WARNING: I will not be responsible for any damage caused to your equipment. Follow instructions at your own risk!

I only used a screw driver to dismantle the camera, and then used a cutter to gently pry out the hot plate. It is secured in place with some sort of a double-sided tape or some form of an adhesive.  It took me 1 day to do all the task (which could have been done in an hour, but I wanted to go slow on this one so as not to make any mistakes). Just a note, be careful not to short any loose terminals especially the part of the circuit where the flashbulb is connected as it could literally fry the circuit board even when the batteries are not connected (the capacitor stores charge/power).

Removing the plate alters the light path such that it now focuses at a point a few millimeters in front of the sensor. Thus a replacement clear glass is needed to restore focus. If you do not have access to it, another option is to cut a few millimeters from the 3 plastic pillars that support the sensor. By doing so, you are actually moving it by a few millimeters closer to the lens, thus, focus is achieved. You may however, just remove the hot plate and leave it as is. Just use manual focusing. The only drawback would be difficulty in achieving focus at infinity.  It shouldn’t be a problem however,  if you will use it in conjunction with a telescope through afocal imaging as shown below:

Image taken with an IR-modified Canon S3IS through afocal imaging

While the camera was intended primarily for imaging targets at H-alpha and infrared wavelengths, as a consequence of the hardware modification, the camera now has an added feature typical to cameras with the hot plate removed, as shown below:


Through this modification, your photos will have a different feel, you can see through thin plastic, and you can take photos even in complete darkness (like the one you see in movies), using an infrared lamp.

I also took this opportunity to install a do-it-yourself (DIY) cable release to the camera. Each key in this numpad is connected electronically to a particular key on the camera. I resorted to this because I wanted to be able to operate that camera remotely while imaging. It’s a bit frustrating to lose a target simply because I ‘touched’ the camera. The cable release is connected via a 25-pin connector which could be clearly seen protruding from the side of the camera.

Do-it-yourself cable release
Wires leading to and from the camera
Canon S3IS modified for astrophotography: DIY hot plate removal, DIY adapter, and DIY cable release

Keep in mind however that by opening the camera, please understand the risks involved in the event of an accidental damage.

Related link: Timing Astronomical Events using CHDK

For tutorials on how to get started with astrophotography, click here.

For DIY astronomy projects useful for astrophotography, click here.

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© Anthony Urbano (Manila, Philippines)

11 thoughts on “IR-modified Canon PowerShot S3IS

  1. That is a very nice setup…
    With the remote control and the T ring, Did you do that yourself?
    Is there some barlow lens in there also??

    • Yes, I built the T-ring and the remote control myself. I have access to a machine shop where I fabricate all sorts of stuff from adapters to gears, etc. And also, as an electronics enthusiast, I love building these kinds of stuff.

      There are no barlows here, just an afocal setup: Canon S3IS + DIY adapter + eyepiece :)
      Thanks much and clear skies!


  2. […] Re: What Camera Do You Suggest? Sorry for reposting but I have managed to find the article that I mention. Link below I have read somewhere, but cant remember where. The Powershot S1, S3 or S5 IS and others, are being modified for AP, and are excellent because of the firmware hack "CHDK", allows you to take RAW at any ISO or Exposure and many other settings. Basically "CHDK" takes the old camera and turns it into a monster. These old cameras can be picked up very cheap second hand mostly under $100, I see there is one on EBAY bid at $10. They also have high quality video giving the option same as that of webcam AP. I intend to investigate this option again in the near future, as I too have an old S3IS, but currently too busy looking into tracking for my dob. Hope this helps, cheers Zedd Many thanks to Eteny for this. http:// […]

  3. Many thanks for sharing and spent time on doing so! Question…where or how you power your DSLR camera? I could not find any article of yours addressing this….. Would you be able to share your info?
    Robert (Calgary,AB)

    • Hi Robert,
      I only use a pair of Canon lithium batteries, and a third-party (non-Canon) battery grip that houses AA batteries. You may find out more about the battery grip here :) I am also working on a DC to DC converter, to convert 12 V 36 A from a lead-acid power-pack (field battery) to a voltage level suitable for my camera, which is 8 V 1 A. More about the field battery here. For info on batteries, chargers, and converters, click here.

  4. Hi! I’m a bit late but… Thanks for the article!
    I’m interested in this S3IS hack, but I’ve got a question raising in my mind: you mention that it is ‘mandatory’ in order to maintain the camera’s focus capability, to replace the hot-plate with a clear glass!
    But where can you find one of it? Or how can you build it by yourself?

    I’ve searched on the Net, but the only things I’ve been able to understand are a bunch of infos about Infrared Replacement Filter. So, given that I am a total noob on this field, may I also ask you wath’s the purpose of these IR replacement filter?

    Thanks a lot ;)
    Best regards

    • Hi Liknus,
      By removing the hot plate, the camera loses the capability to auto-focus. If you wish to retain that capability, you need to restore the proper path of light by replacing the hot plate with a glass plate that does nothing — a clear glass. You need to look for a clear glass with the same thickness and ask someone to cut it at the same dimensions as the hot plate. For DSLR cameras, there are commercially-available clear glass replacements. However, for other types of cameras, this is simply difficult to find. If losing auto-focus is a non-issue, then you can just simply replace it with nothing (just remove the hot plate). Good luck!

      • Ok! I think I got it. It is a standard glass, with no ‘features’ other than being completely transparent! Right? ;)
        Thanks indeed for your kind reply! ;)

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