Hello Earth

With just one hand held up high... go to sleep, little Earth - Kate Bush

A learning space

These pages are as much a place to post my efforts as they are about helping others - I've learned and benefited so much from others, time to pay it forward. There are of course professional tools out there at professional fees, but here I am concentrating on what is available for free, and deliberately not being exhaustive.

These pages reflect my current astronomical interests, less so previous stuff. Please click the navigation button at upper left to jump into details.

As I note elsewhere, here I am using the term HDR, High Dynamic Range, in its generic meaning of combining separate exposures for faint shadows and brilliant highlights into one image that attempts to convey what the eye saw. Those of us familiar with the jaw dropping Hubble Space Telescope images of the universe, and before that from David Malin on film, accept these HDR images without thinking. They show detail right from the faintest of tails and galactic cirrus right into the core, sometimes in the almost lurid colors of ionized hydrogen, sulphur, and oxygen, yet these are normal to us astronomers. But crank the contrast/saturation or tone-mapping on a terrestrial subject and a flame war erupts, and HDR gets a bad name because it becomes synonymous with gaudy, exaggerated images that are more appropriately called art. Let's minimize extreme reactions by choosing the title and captions carefully, to prepare the audience to interpret the image through the appropriate "lens" and their previous experiences. Under a dark sky with the Milky Way arching overhead, the grass may be green and the leaves on the trees may be red, but it "feels wrong" to see it in a picture because no one can experience that! Please understand that some people will be able to live with (even relish) this duality but others' won't or will need another decade or two to accept.