Partial Ursa Major (Big Dipper)
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The photo below is a combination of three 8-sec photos. This combination technique is called "stacking" which is equivalent to exposing the Big Dipper for 24 sec. You can see the 4 brighter stars and also stars down to +7th magnitude (pretty dim stars). The alpha Ursa Major is a red giant star. The 4 brighter stars of the Big Dipper are clearly captured in their proper colors. For photo of full Ursa Major.

(mouse over the photo to see star chart)
Camera: Canon G1 Digital Category: Astronomy
Condition: Outdoor at Night Ext. Light Source: None
Format: JPEG 2048 x 1537 (fine) F-Stop: 2.5
Speed: 8 sec Exposure Comp.: 0
ISO: 100 Metering Mode: Center-Weighted Ave.
White Balance Mode: Daylight Distance: Infinite
Focal Length: 21 mm Tripod: Yes
Filter: None Resized: Yes
Flash: None Editing Software: Photoshop 6
Corel Photo 9
Other: I have become a believer that digital cameras can do astrophotography quite well when "darkfield subtraction" and "combination" techniques are used. "Darkfield subtraction" can remove CCD noise and "combination" can produce the effect of a longer exposure.

As shown above that stars we cannot see with our naked eyes and also in the first 8 sec photo can be revealed brilliantly in the combined photo.

© 2001 by Arif. Email at arif06880@yahoo.com.