[Comm2011] FF - gain

[Gijs Verdoes Kleijn]

Dear Koen,

Analysis of rawdomeflats in z-band are consistent with the gain change 
inferred by the gain recipe. See : 
http://wiki.astro-wise.org/projects:omegacam:commissioning:gain .
We'll check stellar photometry before and after gain change as well.
Cheers, Gijs


Konrad Kuijken wrote:
>
>>
>>
>> - when comparing similar exposures with different electronic filter
>> settings in fact 31 out of 32 chips show signal changes corresponding to
>> gain change deduced from the "gain recipe". So it seems gain recipe
>> works well, and there is indeed a different effective gain for different
>> filter settings.
>>
>
>
> Hi Edwin,
> THe fact that the gain recipe gives different results for different 
> filter settings does NOT necessarily mean the gain changed. The recipe 
> assumed that the filter does not have any smoothing effect but this 
> may be wrong. So photometric tests of the gain are very important. 
> Can we do this test quickly?
> Koen
>
>
>
>
>
>> All this will be further investigated coming days.
>>
>> its amazing we can already do all those things!!
>>
>> When involving astrometry, which we can , we can even have a look at
>> gain changes over the fov and  and make fisrt guess of illumination
>> correction. Will be done coming days.
>>
>> Edwin
>>
>> -- 
>> -------------------------------------------------------------------------
>> Prof. Dr. Edwin A. Valentijn       University of Groningen
>> Coordinator Target                 www   : www.rug.nl/target 
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>>
>>
>>
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-- 
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|dr Gijs Verdoes Kleijn         |   astronomer                     |
|e-mail: verdoes at astro.rug.nl   |   OmegaCEN / Kapteyn Institute / |
|www: www.astro.rug.nl/~verdoes |   Target                         |
|tel: +31-50-3638326            |   University of Groningen        |
|mobile: +31-654658050          |   postal address:                |
|                               |   Kapteyn Astronomical Institute |
|                               |   Postbus 800, 9700 AV, Groningen|
|                               |   The Netherlands                |
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