I know precisely bugger all about how photography really works. It sits in the 20% of the “how the world works pie chart” under the heading “no idea at all”. Included in this ever widening slice are questions such as “why doesn’t electricity fall out of the socket when you take the plug out” and “Big Brother, what the fuck?”
But proper followers of the dark art actually talk mainly of light. And carrying light through complex multi layered lenses becomes stupidly expensive as the focal length increases.Or, in my case, just turn the ISO up and live with a bit of graining 😉 This picture was captured on the end of about 400mm of Tamron lens.
The Blackbird (actually it’s a female, so it’s brown, go figure) is around fifty feet away on next doors garage roof. To make life doubly difficult, the insanely clever camera has to calculate the correct exposure against a gray sky metered through a grubby double glazed window.
How does it do that? It’s in the 20% somewhere.