Cats have excellent night vision, because the pupils of their eyes can open up so wide, to let more light in. They can also see well in bright daylight because the pupils shrink and let less light in. This is exactly the same as the aperture on a camera, and it got me thinking: can I […]Read more "Feline light metering"
I now have three infrared filters and one ultraviolet-pass filter of varying specifications, for different purposes. Two of the IR filters are cheap, one of them was expensive and the UV-pass filter was found in a charity shop and I have no information about it. They all behave differently – so I wanted to test them […]Read more "Putting my infrared filters to the test"
I wanted a solar filter for my camera, for safe observation and photography of the sun. Typically these filters have an optical density of OD 5.0, which for photographers is ND 100,000. This means that only 0.001% of light is allowed through the filter. You can buy pre-made solar filters, but they are expensive and […]Read more "Making a solar filter"
A friend of mine is a researcher in the field of chemical physics. This week, he invited me to his lab to take a photograph of his 5 megawatt laser, which strikes a copper target and makes a plume of plasma that lasts for just a few fleeting nanoseconds. Normally, I like taking photos of […]Read more "Frickin’ laser"
I’ve been practising traditional silver-based black & white photography for a couple of years but today it occurred to me that I don’t really know what is going on with the various chemicals. It’s just a process of remembering which bottle is which. I had a vague idea of what was going on, but I […]Read more "The chemistry of black & white photography"
Everyone knows that Coke is bad for their teeth. It’s sugary and acidic. The acidity is at least partially caused by carbon dioxide (CO2) dissolved in the water, to make carbonic acid. We also know that if you pour a Coke and leave it, it fizzes away as the CO2 comes out of solution and […]Read more "Is Coke worse for your teeth when fizzy or flat?"
Outdated medical technology isn’t normally the kind of thing I’d be interested in, or would write about – but I was given some old glass autoradiographic stripping plates. I didn’t know what they were at the time – I assumed they were normal photographic plates, but I’ve done a little light reading. Autoradiography The gist […]Read more "Autoradiographic plates"