wpo - digital camera nightsky sampler

My Astrophotography goes instant [Nov 2002 Astronomy Now - Focus] uses images, best viewed for clarity, via this webpage.
A digital still camera on a static tripod will record fainter stars than can be seen with the unaided eye in 20s exposure - no telescope is needed. Exposures in excess of ~20s [50mm fl -135 equiv] must be tracked on an equatorial mount, like the gas clock drive or piggy-backed on telescope, to counter the star's diurnal motion across the sky.
As stars are points of light only the aperture of the lens iris and exposure duration affects results - f/ratios and a big front element lens are irrelevant. Prosumer CCD imagers are typically <1/16 the size of 36 x 24mm film format and lenses are tiny too. Iris apertures typically vary from 3.5mm diameter [f/2; 7mm wide-angle fl -28mm 135 equiv] to record stars to ~mag 7 and about 14mm diameter [f/3.5 50mm tele fl - 200mm 135 equiv] to record stars to ~mag 10.
Earth space Aurora    Noctilucent Cloud    Int Space Station
solar system    Saturn occults + planets align    Mercury+Venus
astro-images by James Weightman    Minolta D7 review    moonlight scenes    afocal images via camera bracket

Images below of 1st quarter moon terminator via Minolta D7 handheld in afocal mode to x75 eyepiece on 30cm SCT.
Inset - direct Minolta D7 image of Moon without telescope ie 50mm fl + x2 digital zoom = 400mm effective fl.

Images taken at late dusk, where the deep blue sky appears to suppress the yellow sodium skyglow, gives good stellar penetration to mag 10 in 30s exposure at f/3.5; 50mm fl [200mm 135 equiv] piggybacked on Meade LX200 as adjacent negative cropped image.
When fully dark a strong sodium yellow skyglow [blue in negative images above] is recorded even in clear cloudless skies. Experiments with a Jessop's 80A blue filter before the lens effectively suppresses the sodium skyglow but the filter has a daylight factor x4 [2-stops] or loss of 1.6 magnitudes.
images/text copyright - Maurice Gavin - Oct 2001- Dec 2002