Removing the bayer filter for UV photography

[gtoal]

There's an interesting blog post here about UV photography at https://stereopi.com/blog/deep-ultravio ... -hq-camera but there's no comment facility on the blog so I'll follow up here instead.

A team from the UK did something similar back in 2016 using the regular pi cameras rather than the HQ camera: read about it at https://pmc.ncbi.nlm.nih.gov/articles/P ... -01649.pdf - they removed the bayer filter chemically (using Dupont's Posistrip EKC830) rather than mechanically.

I'm more interested in IR images myself (having recently thrown together a camera using the NOIR cam plus an external IR notch filter to block the visible light) but I wouldn't mind having a go at UV as well some day - but the blog article above uses about $300's worth of filters to pass UV and block visible which is rather expensive for a weekend experiment. (In contrast, a good equivalent filter for IR photography costs about $3 each on eBay - https://www.ebay.com/itm/156413343183 - and a close substitute actually came free with the NOIR camera (if you ever wondered what that dark blue square of plastic was for...))

So does anyone know what would make a good UV notch filter for a pi cam that doesn't cost as much as those expensive SLR ones from maxmax.com? ( https://maxmax.com/shopper/product/1502 ... -2mm-thick and https://maxmax.com/shopper/product/1509 ... er-in-58mm )

An IR camera is good for studying crop growth and a UV camera is good for studying pollution. There are lots of fun applications for both of these technologies, they're definitely worth having a play with. At the moment I just want to take some outdoors black and white IR images which I've wanted to do since I was a teenage amateur photographer in the 70's and it was done with film at the time, but beyond my ability or income! 50 years later this stuff is now cheap to experiment with and still just as much fun.

(And the relevance to the stereopi system is that it can probably be used along with a beam splitter (semi-silvered mirror) to align the two images - IR+visible or UV+visible - from two cameras, so that we can do image processing on the various image components without having to correct for the stereo separation...)

G

[Realizator]

Uh, I guess it's a pro photography scope, and I'm an amateur here
The guys from the article make scientific things, so even removing the original Bayer filter was extremely expensive.

I can't provide the exact model or source of inexpensive filters, but your link is interesting. I can only add that the IR filters in our HQ camera kit are the same as those used in the HQ camera, and we ordered them directly from the HOYA corporation. Maybe HOYA also produces narrow UV filters.