For some reason I missed this from a month or so back. I’m subscribed to David Langford’s Ansible newsletter on science fiction topics, but for some reason I missed reading March’s issue where he noted the death of John Christopher. […]
READ MOREOn a whim at the end of last week I bought a set of Vivitar macro extension tubes for my Canon XTi. These are pretty neat: they pass through the auto-focus and auto-exposure signals from the camera to the lens, making them easier to use. There are three in the set: a 13mm, 21mm, and 31mm tube. If my mathematics is correct, this makes seven possible tube lengths since you can combine them in any order (call them A, B, and C, then the possible combinations are A, B, C, AB, AC, BC, and ABC). […]
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