Wellington Astronomical Society
WAS www.was.org.nz

Wellington Astronomical Society
WAS www.was.org.nz

Astro and sky photography page. Extreme Imaging.

Hi All,

Last Saturday night was reasonably good and I spent the evening at Puatahaui imaging the Lagoon Nebula. This is the result of the nights work; it is a stack of about 14 images ranging from 30 seconds to 2 minutes through a MEADE 12-inch LX 90 at f6.3. My recently upgraded computer no longer runs my Adobe Photoshop (sigh) and I haven't done any enhancements.
Cheers
John

For sky photgraphy the basic requirement is for a camera and filter system that can handle the extreme range of brightness encountered. It is fair to say that often the photographer is exploring the extremes of imaging process.

Day time requires ND (Neutral density) and polarizing filters, often the camera is shut right down to minimum sensitivity.

Night time requires low noise and stability as often the camera is opened right up to maximum sensitivity.

The main issue becomes the range of brightness across the image, and it is often more appropriate to take a bracket of images, recombining them in photoshop to reconstruct what the observer saw.

Day.

For the sun its relatively easy to use the same filters as for telescopes; mylar with aluminium deposited both sides. Made by Baader. Ha (Hydrogen is Alpha) by Coronado is better if you can afford the $6000.

Sometimes the dirty air and / or clouds conspire to act as suitable variable density filters and adjust the strength of the sun or moon to balance it with the scene, making in-camera final shots possible.

Another method is to use a flash or other in-fill light to create the possibility of in-camera images, such as these: