April 20, 2011 9:32 am
Here’s a resume of industrial life in north Taranaki. The title is a little deceptive because the power is not going to Paritutu Rock but coming away from it, or rather, right under it, from the power station below our horizon, at Port Taranaki. The station has supposedly been decommissioned but the pylons still hum with transmission. Actually higher than Paritutu is the Stalinist chimney beyond, at 185 m (600 ft). Its location right next to the only natural landmark on this coast for 300 km is a remarkable testimony to New Zealand’s commissar planning of the late 1960s.
The converging verticals were hard to avoid from this low viewpoint, necessary because of the brilliant spotlight at the Dow chemical works, which lights up the rock. A short trial shot of 30 seconds at f4 showed how to get to a 15 minute exposure: drop the ISO from 2000 to 400. When you reach the last f-stop on your lens the only remaining adjustment is to light sensitivity, if you want to make extended exposures for the stars.
Getting good star trails on a wide angle takes longer than it does on a telephoto. Comparing the lengths of the streaks above with those taken with the 85mm telephoto the same night in no. 39. Mt Taranaki at night from Centennial Drive, I estimate that the blaze above would take just 9 minutes with the longer lens, regardless of the need for a more distant viewpoint.
Wide angles still have their uses for the starry sky though. If you are intent on showing the curve of stars around the earth’s rotation points – the poles – then a wide angle is the obvious choice, and the wider the better. On a moonless evening, start with 30 minutes at f16, ISO 200. If your digital battery won’t last that long, use a film camera that does not need a battery for its shutter operation.
28mm, ISO 400. 913 seconds (15.25) minutes at f16. Incandescent light balance.
Posted by Barney Brewster
Categories: Night photography