Wednesday 27 March 2024

Simon Marsden: Online exhibition and print sale

I'm delighted to have been pointed to a new online exhibition from the Centre for British Photography of infrared photographs by the legendary Simon Marsden ... subtitled Visions of a Ghost Hunter.

Here it is: britishphotography.org/exhibitions/70-simon-marsden-visions-of-a-ghost-hunter

The exhibition is online starting yesterday (March 26th) and running until April 26th 2024. There are 23 photographs of his characteristic ruins and landscapes, all exploiting the idiosyncratic style of Kodak's much-missed 35mm High Speed Infrared film.

Sadly, the £1500 price tag is too much for me but these are wonderful images and well worth a view.

The show is online because the Centre for British Photography have now closed their gallery in central London as the lease ended early; but this was apparently only ever intended to be a temporary space. Follow their web site for updates.

Sunday 24 March 2024

Ed Thompson Infrared Story

Back in September 2016 I wrote about a colour infrared project by documentary photographer Edward Thompson called The Unseen.

Ed has been building up a YouTube channel called Pictures On My Mind and this includes some explanations of the work he did with some of the last remaining stock of infrared Aerochrome, which was basically the same as infrared Ektachrome EIR.

The latest video outlines at length the shooting he did in Pripyat, Chernobyl, and included in The Unseen. This part of his infrared journey started with finding out that false-colour infrared film was widely used in forestry. The normal red look of healthy foliage would tend towards magenta when the foliage was 'stressed' and it was a good way of determining forest health from a distance.

Alongside the Chernobyl video is another one going into more detail about other parts of the Unseen project, but because it includes some nudes (to demonstrate IR's ability to allow you to see a few millimetres under the skin and to echo demonstration shots published by Kodak) this video is restricted and Ed has had difficuly making the most of his whole channel.

This video passes on a couple of interesting pieces of information about Ed's technique. One is that, certainly until he was totally au fait with the idiosyncratic film, Ed bracketed the shots. I always found this was essential for any infrared film but I have come acress photographers who are able to get it spot on without bracketing. The other is that he says in the video that he used a visually-opaque R72 filter to get the very deep reds that he achieved. Usually you'd use a minus-blue filter (yellow) with EIR. Those reds are mind-blowing!

Each section of The Unseen represents different applications of infrared photography with others including art investigation and restoration and medical imaging. (In fact the third edition of the standard text, Photography by Infrared, was written by Lou Gibson, who was a pioneer of medical photography.)

So I can recommend Ed's YouTube channel and especially The Red Forest of Pripyat Chernobyl. Enjoy!

Thursday 8 February 2024

Uranus is not as boring as we thought

The conventional view of Uranus has been that its apparent surface shows few, if any, distinguishing features. The images from the Voyager 2 probe in the 1980s showed what Nasa describes as a "placid, solid blue ball".

The James Webb telescope, using infrared wavelengths rather than Voyager's visible ones, shows something else. In this light the north polar ice cap becomes visible. (Uranus, bizarrely, rotates almost at right angles to all the other planets so the north pole is, in this configuration, pointing towards us.) Some storm clouds are apparent as well, and the planet's rings show up clearly.

I've not been adding to this blog of late, so I realise I am a bit late with this as a group of photos were released by Nasa back in December 2023. The Nasa web page has copious information about the set, which includes wider field photographs (also larger than the image above).

That Nasa page doesn't give information about the wavelengths used for the image. There's a more detailed report from Scientific American, which notes that image is built using wavelengths of 1.4, 2.1, 3.0 and 4.6 microns. Since photographically, we're more used to nanometres this means 1400, 2100, 3000 and 4600 nm.

[Image credit: NASA, ESA, CSA, STScI]

Monday 14 August 2023

Thermal images of sun-baked Phoenix Arizona

The Guardian recently published a photo set matching far infrared images of Phoenix with ordinary photographs.

The images were taken by Carlos Barria, using a Flir thermal camera, which also shows a point temperature (in Fahrenheit).

It's an interesting set, taken in late July 2023 and which "reveal a Phoenix where concrete on the street registers 150F (66C), outdoor workers’ bodies reach 105F (41C) and homeless people swelter, surrounded by surfaces as hot as 143F (62C)" and it's unusual to see visual and thermal images matched in this way: you can swipe between the two.

The link is here: Thermal images of the US heatwave in Phoenix, Arizona

Monday 10 July 2023

Infrared generative AI

I've been 'playing around' with a couple of generative artificial intelligence engines that carry out text-to-image. I was interested in how they understood the look of an infrared photograph.

This was partly because I find that at least one of my IR photos has found its way into the models used for generative AI. Without permission of course!

I tried a fairly simple shot; that of a tree. A good test for the basic Wood Effect. The results are quite good and, given how unreal IR photos can look anyway, it would be difficult to tell from the real thing. Sometimes the background detail gives things away but I found I could quickly get good results.

The two I tried are Stable Diffusion and Adobe Firefly (chosen simply because I have access to them) and the text prompt is the same for each: Infrared image of an oak tree in a meadow.

This is the Firefly result ...

As you can see, I got a false colour image without specifying, and in this case it's not a bad result. Often the system would put arbitrary colour washes over the image, but here the result is as you'd expect.

This is the Stable Diffusion result ...

Here, it's black & white straight away. Again, a pretty good result.

I did also try to generate some thermal images but neither engine could get anywhere near what you'd expect, presumably because there are not many, if any, thermal images in the training set.