Sun, clouds, lightning, rain; yes it’s a British summer! The night of the 27th clear spells gave way to a hot (27C) & humid day yesterday, with very little breeze. That’s just what I needed to demonstrate an answer to Tamsin’s question … How do you take the images of the tree canopy that I see in magazines?
So off we trundled with tripod, camera & fisheye lens, we took 4 differently exposed views of the tree canopy & returned to the computer to process the 4 exposures into one high dynamic range (HDR) image. Whilst walking the conversation turned to "How are zoom lenses made?" – hmm, this daughter keeps me on my toes 🙂 Anyway the resulting image is below:
The full res image (not posted here) shows details of leaves & bark whilst retaining plenty of sky detail, all in all a good recommendation for HDR technique.
As evening came any ideas of a night’s astrophotography were blown away by rather ominous looking thunderclouds. An opportunity for an early night? Well maybe not, 2am found me sat in the bird hide watching some beautiful lightning & being lulled to sleep by the patter of rain on the canvas. Naturally I had a camera with me …
Lightning occurs when droplets of ice & rain, circulating in the thunder cloud, build up electrostatic charge. The charge created can be huge and an equal but opposite charge is induced in the ground below the cloud. The highest electrical field exists on the tip of objects such as tall trees, electrical leaders form that eventually connect cloud & tree top and it is then that a huge discharge leading back up the ionised air, into the cloud, takes place. This is the bright flash that we most often see. Most lightning strikes are a discharge of negative charge from the cloud with a typical current of 40,000 amps; potential difference may be several hundred thousand volts. However lightning strikes that emanate from the top of an anvil cloud can result in a positive discharge, these bolts carry significantly more energy and are both rarer & more dangerous.
Lightning storms in Wales are rarely viewable without a large amount of associated rain, so trying to keep equipment dry, whilst photographing the view, can be a bit tricky but well worth it I think. So Aberllefenni & Corris had a stormy night, but all seems fine today.
Trivia: Did you know that the path of a lightning bolt may only be 1 or 2 inches wide but 1 mile long.