National Camera Exchange is a good place nearby (in Golden Valley, Minnesota) to consider to go for buying camera equipment such as filters.
20161211/https://www.natcam.com/locations/Golden-Valley/
20161211/https://www.natcam.com/?s=IR+filter&post_type=product
Possible filters to consider. On from Schott, one from Hoya.
20161211/http://www.ebay.com/itm/Schott-RG780-46mm-x-2mm-Longpass-IR-Infrared-87-Filter-fits-Kuribayashi-35mm-/302034604698?hash=item4652aa529a:g:sf8AAOSwdzVXpnTg
20161211/http://www.ebay.com/itm/Hoya-U-360-52mm-x-2mm-UV-Pass-Camera-Filter-Ultraviolet-Dual-Band-IR-/291967426367?hash=item43fa9d5f3f:g:oUcAAMXQY8JRgPXy
20161211/Google schott rg780 filter
Here is the data sheet.
20161211/http://www.sydor.com/wp-content/uploads/SCHOTT-RG780-Longpass-Filter.pdf
Here are some cheaper filters.
20161211/http://www.ebay.com/itm/720nm-IR-Camera-Conversion-Filter-29mm-x-25mm-x-1-35mm-LPF-720-2925135-/111542886562?hash=item19f87960a2:g:qr4AAOSwj0NUhfKE
20161211/http://stores.ebay.com/Stock-Optics-Ltd/_i.html?_nkw=IR+Filter&submit=Search&_sid=270817150
This is a very useful information page on optical filters. I should read up more on it in detail.
20161211/http://www.olympusmicro.com/primer/lightandcolor/filtersintro.html
Ah ha! Here’s a filter that seems to do the job. Now that I know what search terms to use.
- IR cut filter
- IR pass filter
20161211/http://www.pmoptics.com/ircutfilters.html
$15. 15 x 15 mm is what we are considering for our Raspberry Pi camera filters.