This "dimming" due to airborne particulates is actually
something that was well researched by scientists and engineers
back in the '60s and '70s when "smoke scrubbers" were being
developed and installed in factories, power plants and chemical
operations.
Example: Coal-fired powerplant used to belch dark smoke from a
tall smoke stack. Most particulate matter fell to the ground (or
stayed in the lower atmosphere) in a nearby zone. CO/CO2 was
usually carried with the particulate and not much actually
entered the upper atmosphere. Now, the particulate is filtered
out and doesn't leave the facility in an airborne state. This
leaves the CO/CO2 to freely leave the area and travel throughout
the atomosphere.
Not that it means anything as it just might be coincidence, but
the global warming and CO/CO2 charts show a marked upward trend
at the same time scrubbers/filters were being installed in power
plants, founderies and factories.
As to how this relates to photography, well, Walt's little
humour might not be so far off. It USED to be that you could
shoot Sunny 16, but I've usually needed to augment that with
another 1/3 stop.
AG
__________________________________
Do you Yahoo!?
Yahoo! Mail - You care about security. So do we.
http://promotions.yahoo.com/new_mail
==============================================
List usage info: http://www.zuikoholic.com
List nannies: olympusadmin@xxxxxxxxxx
==============================================
|