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Re: [APML] Light pollution filters and Comet NEAT



Thanks for the advice Philip--I'll definitely start without the filter.
Heck even if the pictures aren't great the comparison will be interesting.

At the risk of messing up everything, it looks like the clouds may hold 
off for a while this evening!

Cheers--steve

Philip Perkins wrote:

> Hi Steve,
>
> I'll second Jeff's comments and hope you get a chance to try it with 
> and without the filter.  If it was me, I'd try it without first of all 
> - using a light pollution filter on a broadband object is always going 
> to be a compromise.  Even though the IDAS is a lot better than most, 
> it will still be excluding sizeable parts of the comet's spectrum.  
> The comet is getting fainter all the time but as of last Saturday it 
> was bright enough to be recorded easily even in moderate light 
> pollution and quite strong twilight.  I'd be interested in seeing 
> results with and without filter, assuming your clouds disappear!
>
> --Philip
>
> At 14:36 18/05/2004 -0700, you wrote:
>
>> Thanks Jeff--I'll give it a try.
>> What I really need is a cloud filter!
>> steve
>>
>> Jeff Ball wrote:
>>
>>> Steve,
>>> To my eye that looks like the filter is cutting off the peak of the
>>> comet spectra around 540-560 and another cutoff around 580-600.  I 
>>> guess
>>> below 540 you would record the comet well and above 600 it would be
>>> spotty.  I hope you get a chance to try it filtered and unfiltered and
>>> share your results.  Good luck.
>>
>
>
> Philip Perkins
> <pgp@astrocruise.com>
> Wiltshire UK & Luberon France
> http://www.astrocruise.com
>
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>
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