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Old 21-07-2015, 10:03 PM
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cometcatcher (Kevin)
<--- Comet Hale-Bopp

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Join Date: Jan 2005
Location: Cloudy Mackay
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That's a quick one Ray! Good example of 15 seconds. Anyone for 10 seconds?

Quote:
Originally Posted by Robert9 View Post
I did a quick calculation and 15 secs. at ISO 6400 is equivalent to 4 minutes at ISO 400.
For daylight photos, yes but not for astronomy. With my Pentax for instance, 15 seconds at ISO 6400 is equal to (after stretching) 15 seconds at ISO 400. The noise increases at virtually the same rate as gain.
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