[time-nuts] A real world project need for timing accuracy...

jimlux jimlux at earthlink.net
Tue Nov 2 13:28:18 UTC 2010


Bob Camp wrote:
> Hi
> 
> Ok, I mis-understood the question.
> 
> In my experience, you can have big buck (as in many thousands of dollars) optics and not see .2" holes at 800 yards. The bull's eye is a *lot* bigger than the hole the bullet made. 
> 
>
0.2" at 2400 ft is about 0.08 milliradian.. or 0.3 minutes of arc.  Your 
eye can resolve about 1 minute of arc... I'm not questioning your 
experience, but it seem that even a moderate power scope should allow 
you to see the holes.  As I recall, the Rayleigh limit for resolution is 
something like 0.7 milliradian/mm of aperture, so 10-15 mm aperture 
would be in the right ballpark..

I can imagine needing more aperture than 3", though.. you're not 
interested in resolving a star, but something more akin to separating dots.




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