[Aavso-photometry] Uses for Old CCD Camera?

[Jeff Hopkins]

Hi Mick,

I have experimented with a 50 mm camera lens on a DSI Pro for BVRI 
photometry of epsilon Aurigae. This technique allows both epsilon and 
lambda (the normal comparison star) to be imaged at the same time. 
The downside is there is severe undersampling and epsilon will come 
out much fainter than it should. This is solved somewhat by 
defocusing the image. This seems against all imaging, but works 
fairly well. It requires some experimenting to get the tight 
technique. The technique is described in fair detail in my new book 
"Epsilon Aurigae A Mysterious Star System." 
http://www.hposoft.com/EAur09/Book.html

Happy Holidays!

Jeff

At 09:37 -0700 12/12/2008, m.j.crook at talk21.com wrote:
>Hi All
>Chapter 2 of the AAVSO CCD manual briefly mentions that camera 
>lenses can be used on CCDs for photometry.
>
>http://www.aavso.org/observing/programs/ccd/manual/2.shtml
>
>Wouldn't this be a great way for beginners to start out? Maybe a 
>basic observing programme could be developed using this type of 
>equipment to encourage beginners (like me) to get involved with CCD 
>photometry. Maybe something on these lines could be done in 
>conjunction with the imminent Epsilon Aurigae eclipse?
>
>Cheers,
>
>Mick
>
>--- On Fri, 12/12/08, Michael Heald <msheald at hotmail.com> wrote:
>
>>  From: Michael Heald <msheald at hotmail.com>
>>  Subject: [Aavso-photometry] Uses for Old CCD Camera?
>>  To: aavso-photometry at mira.aavso.org
>>  Date: Friday, 12 December, 2008, 8:54 AM
>>  Hello! I've upgrade by Meade Pictor 216 to an SBIG
>>  ST-402 with BVIC filters to use with my 8" LX200
>>  classic. I am wondering in the Pictor might be useful for
>>  observations of some sort. Because of hot pixels and
>>  linearity issues, it is limited to about 25 second
>>  exposures.
>>      Would a 50mm to 135mm camera lens yield useful
>>  information when pared with the Pictor? I know that the
>>  images would be significantly undersampled. How would the
>>  accuracy and precision be compared to visual variable star
>>  estimates of bright stars? Best regards.
-- 
Jeff Hopkins
HPO SOFT
Counting Photons
http://www.hposoft.com/Astro/astro.html
Hopkins Phoenix Observatory
7812 West Clayton Drive
Phoenix, Arizona 85033-2439 U.S.A.
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