Re: [APML] Help Needed -- ST-4 and Sky Background

[Aplanatic@aol.com]

Hi Jerry,

> I'm going to try this and send you the data the next time I get out because 
>  I think it's a neat trick.
>  
>  But, I don't think correlating it to limiting visual mag is going to be 
>  worth much to anyone except the individual observer, because two people 
>  with different eyes will see a different limiting mag when they are 
>  standing next to each other under the same sky.

Yes, I expect significant differences between observers.  As a case in point, 
at a star party in AZ I could just make out 6.3 mag stars while an 
experienced observer right beside me (with good eyes) could see 6.8 mag stars 
and occasionally could just make out 7.0 mag stars.  His eyes were clearly 
way better than mine.

Nonetheless, the correlation between LVM and the ST4 readings is a start.  We 
can all look at the trend and scatter in the data and see what we think about 
it.  Also, after getting a feel for your ST4, you can use your individual 
measurements to determine site quality, exposure times, etc.  I think this is 
valuable enough in its own right.  I've already found it very handy.

Dave

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