Monday, 7 October 2019

Blue Mountains in Infrared

Photographer Steven Saphore has used his modified DSLR to take some nice shots of the Blue Mountains national park in New South Wales, Australia. A set of the images has appeared in the Guardian newspaper. The photographs are faux-colour but Stephen has applied the colour subtly, which makes for an interesting variation.

The description of the technique is slightly misleading, in that it implies that the whiteness of the foliage is due to chlorophyll being reflective at these wavelengths, whereas it's the chlorophyl itself being transparent and letting 'light' bounce around in the plant cells. But that's a nit-pick ... the photos are the important thing.

Tuesday, 9 July 2019

Solar panels and 'reflective' grass

I was interested to read in today's Guardian that BP are researching the most reflective kinds of grass to plant underneath solar panels; panels that pick up on top and underneath. The story points out that "bifacial panels can increase electricity output by almost 15% – but this can be much higher if the ground beneath the panel is particularly reflective".

Although the story doesn't mention it, regular readers and fans of infrared photography will know that grass (as well as other foliage) strongly reflects near-infrared light due to the retro-reflective effect of those wavelengths travelling through plant cells. Chlorophyl is transparent to near-infrared radiation. The effect is the same one that makes snow appear white, which is why infrared photos and snowy scenes can be confused.

The Solarquotes blog in 2017 looked at the proportion of solar radiation that a solar panel can exploit. Their context was about UV but if you scroll down the page you'll see a diagram that shows that a silicon solar panel will make use of radiation between 400 and 1100 nanometres. Since visible light extends from about 400 nm to about 650 nm you can see that including near-infrared more than doubles the available energy bandwidth.

All this makes planting grass underneath bi-directional solar cells a logical thing to do. That reflective grass is not just fun for infrared photography then ... or grazing!

Tuesday, 18 June 2019

Infrared astronomy faces a gap

In late 2016 I noted that the James Web infrared space telescope was two years away (in this post) but it now seems that the launch has been pushed back to March 2021 at the earliest. This delay means that there will be a gap in infrared observation capabilities, as the Spitzer is set to cease operation over a year before that.

More information on this can be found on the Scientific American web site.

Friday, 24 May 2019

Photocrowd IR competition

Occasionally photo communities ask for, and sometimes rate, infrared photographs. DP Review have done it in the past and I selected one of their winners for the 2010 Infrared 100 exhibition.

Just launched is one for Photocrowd. If you're a member, or want to join, you can submit photos and rate others. In this case the contest finishes on the 28th. Anyone can view the entries. The ones so far include some interesting ones as well as some strange ones, some of which are (IMHO) not even infrared images! But worth a peruse.

Go to

Wednesday, 13 March 2019

Injections can give you near-infrared vision

Scientists in China and the USA have developed a technique to extend the range of vision by injecting nanoparticles behind the retina (so without any external technology). These particles bind to the photoreceptors in the eye and can convert low energy (near-infrared) photons to a higher energy (green). This has been demonstrated to allow mice to add near-infrared to their range of visible 'colours' with no side-effects.

I first came across this in New Scientist: Mice given ‘night vision’ by injecting nanoparticles into their eyes ... but the full paper is also available online via

One interesting thing about this is that a transfer of energy also occurs in photosynthesis, between types of chlorophyl) and in sensitising film to accept longer-wavelengths.

[Ma et al., Mammalian Near-Infrared Image Vision through Injectable and Self-Powered Retinal Nanoanten- nae, Cell (2019),]