David's Astronomy Pages CCD Image Notes - Session 71 (2004-09-07)

Notes (S66)

Notes (Main)

Home Page

Notes (S78)

Albireo Star Field - Enhanced Image Display & Magnitude Limits

What is the Magnitude Limit of an Image  ?       

Well it depends ...  In the following example a 10 sec image of the Star Field around Albireo is displayed in different ways, with Magnitude Limit that varies between +9 and +15. 

Star field around Albireo (Cygnus) Image - "Normal Display" (Linear brightness scaling,  High Contrast,  Range 147-1460 ADU) β2 Cyg  is not visible in the glare from Albireo (β1)  Magnitude Limit  = +12.5

CCD Image, 10s exposure, C Filter 2004-09-07 21:31h UT (# 71039)

Same Image - "Adjusted Display"  (Linear brightness scaling, Range 0-8600 ADU) β2 Cyg visible, Magnitude Limit  = +11.0

Same Image - "Adjusted Display"  (Linear brightness scaling, Range 0-25000 ADU) β2 Cyg and β1 Cyg clearly separated, Magnitude Limit  = +9.0

Same Image - "Enhanced Display"  (Logarithmic Scaling, Range 105 - 40000 ADU) β2 Cyg visible, Magnitude Limit  = +12.5

Same Image - Enhanced False Colour Display (Logarithmic Scaling, Range 105-16900 ADU, Inverse Spectrum, ) β2 Cyg visible,  Magnitude Limit  = +15.0

CCD Image, 10s exposure, C Filter 2004-09-07 21:31h UT (# 71039)

Back to Top