On 27/05/2021 23:27, T i m wrote:

According to the spec I believe it covers the range of 300-1000 nm
(even though I understand we can only see around 380 to 750 nm etc)
but what I would describe as 'daylight' is all I'm really interested
in re managing general light levels indoors. Given this sensor seems
to be designed to 'see' the sort of thing we see, I think that as long
as whatever light it gets isn't filtered at all, it should be ok.

The sensor you've chosen can see out to 1000nm. Most glasses and
plastics will transit light to near IR

The advantage of using a UV filter is the surfaces will be optically
coated to minimise reflection and maximise transmission over the
wavelengths of interest.

snip

I'm not trying to actually 'measure' anything (although the sorts of
levels are interesting if they are correct and when compared with the
stated light output levels of domestic lighting) but to just get the
comparable levels that could be useful to automate what might equal
'it's a bit dark outside, better turn the light on', or enable the
'turning on a light on in the hall automatically with a PIR during an
overcast day and before sunset' ... sort of thing. ;-)

Interesting. Given everything is relative and open to calibration, crude
or otherwise, I would say any old piece of glass or plastic window would
be fine.