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I'm looking at the module cameras available in Amazon, and it seems a clear choice between the standard module camera and the NoIR version (which is the same as standard but with infrared filter removed). It's not clear from these pages (or the R-Pi blogs on this) if NoIR can be used in bright conditions. The 'infrablue' filter it comes with enhances the infrared functionality; it doesn't appear to enable daylight functionality.

Can NoIR work in daylight or be adapted for this, perhaps with any compatible infrared filters available? If so it sounds like it may be worth getting NoIR and save on buying two cameras.

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The NOIR camera should only be used in low light conditions unless you know what you are doing. This blog entry indicates that full-light images obtained with the NOIR camera will likely have color distortions:

They [the manufacturer of the RPi cameras] told us they were particularly concerned that users would try to use a camera board without a filter for regular daytime photography, and be would be upset at the image quality. (There’s a reason that camera products usually integrate an infrared filter – the world looks a little odd to our eyes with an extra colour added to the visible spectrum.)

  • Thanks I didn't spot that. Do you suppose NoIR would still be the preferred choice for general indoor use? – geotheory Jan 7 '14 at 10:01
  • I haven't used the NOIR model yet, but I suspect it is more appropriate for night-time imaging. – bobthechemist Jan 7 '14 at 13:02
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As mentioned on the Pi NoIR specifications webpage it is only missing an InfraRed filter. So you can just buy a separate "IR-cut filter" (search on eBay or elsewhere) and use the Pi NoIR in daylight with such a filter as people have shown (e.g. here). There are also IR filter switches so one can switch the IR filter in for daytime use and out at night night time so it can see Infra Red (e.g. here and here). There's even commercial offerings (e.g. from modmypi) that provide this all built into one module.

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NoIR version of the camera should be used mostly when you need to illuminate your scene with IR (=near infrared) illumination. These cases are pretty special and if you don't know why would you use NoIR version, just buy the normal one. The cases where one would need NoIR version are as follows:

1) "invisible" illumination in darkness, e.g. for surveillance purposes or for other uses when visible light is not desired. In that case, you would use LED IR illuminator, the same that comes with many "see in the dark" surveillance cameras.

2) Overpowering the undesired stray light coming into the scene. For example, in many machine vision applications one needs strict control of the lighting conditions. In that case you would use LED IR illuminator in combination with the visible light cut-off filter (very dark red/black, see here:

http://www.flong.com/blog/2010/a-brief-note-on-infrared-filters-87-vs-87c/

This works quite well when artificial light is the problem, as basically none of the power saving light bulbs emit in the IR spectrum. Bigger problem with incandescent lighting and pretty difficult to mask out the sun.

3) Using special IR sources, like lasers for illumination. In this case you would need to match the filter with the (very narrow) spectrum of the laser.

4) In some cases people like to observe natural environment, illuminated by sunlight in IR (e.g. plants become bright white). In this case you would need to add visible light blocking filter as well.

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