A simple table for unguided exposure limits and a lot of other data for
exposure limits relative to sky glow.
<http://www.khurramhashmi.org/astrophotography-and-astronomy/useful_data_for_astrophotographers.html#unguided_imaging>
Chuck Norcutt
On 7/29/2014 6:03 PM, Mike Gordon via olympus wrote:
I have no idea how to find it now but I used to have a reference
table (from the web somewhere) where you could determine the maximum
exposure >>time for a motion free image given focal length and
magnification.
I vaguely recall the "600" rule where 600mm lens can be used at about 1
sec--somewhat depends on angle of declination too. max time=600/fl
Oh, I see this calculator--better yet.
http://www.sceneplanner.com/tool3.php
Yea, there is also a phone app of course.
I am still still not sure how to use DSS w/o much repositioning. Better
watch a tutorial.
Mike
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