[Aavso-photometry] Spectra of GE Reveal bulbs

[Robin account]

Hi David,

The CCD response is part of it but the grating and the rest of the optics 
come into it as well so you really need some sort of standard illumination. 
(An unfiltered incandescent lamp is a pretty good standard black body source 
provided you know the filament temperature) You can also get an approximate 
instrument response by taking a spectum of  a known star and dividing it by 
the published spectrum, though this neglects any atmospheric effects.  You 
can see an example walk through of the complete reduction process I use for 
low resolution spectra in a presentation on my website here if you are 
interested.
http://www.threehillsobservatory.co.uk/astro/spectroscopy_10.htm

Robin

----- Original Message ----- 
From: "David Daiku Trowbridge" <David at tinyblue.com>
To: "AAVSO Photometry" <aavso-photometry at mira.aavso.org>
Cc: "'Robin account'" <robin at leadbeaterhome.fsnet.co.uk>
Sent: Saturday, December 27, 2008 2:36 AM
Subject: RE: [Aavso-photometry] Spectra of GE Reveal bulbs


>
> Robin,
>
> That's right, I have not corrected for the instrument spectral response. I
> assume I would have to divide by the quantum efficiency of the KAF-0402 
> chip
> in the ST-7 camera, such as that shown at
> http://www.sbig.com/sbwhtmls/app_notes.htm
> But I don't have the data for that curve. Any idea where one could find a
> table of QE values vs. wavelength for this particular chip?
>
> David
>
> -----Original Message-----
> From: Robin account [mailto:robin at leadbeaterhome.fsnet.co.uk]
> Sent: Friday, December 26, 2008 4:27 AM
> To: David Daiku Trowbridge
> Subject: Re: [Aavso-photometry] Spectra of GE Reveal bulbs
>
> Hi David,
>
> These are uncorrected for the instrument spectral response I would guess. 
> It
>
> shows the effect of the Neodynium glass nicely (I did not realise there 
> was
> another absorption band in the IR)
>
> Robin
> www.threehillsobservatory.co.uk
>
> ----- Original Message ----- 
> From: "David Daiku Trowbridge" <David at tinyblue.com>
> To: "AAVSO Photometry" <aavso-photometry at mira.aavso.org>
> Sent: Wednesday, December 24, 2008 7:13 PM
> Subject: [Aavso-photometry] Spectra of GE Reveal bulbs
>
>
>>
>> To follow up on the discussion about GE Reveal bulbs, I used an ST-7E
>> camera
>> on a DSS-7 spectrograph to obtain spectra for a 60W Reveal bulb and a 60W
>> regular incandescent bulb, at full brightness and dimmed. The spectrum
>> images were reduced and calibrated using a Neon calibration lamp. The
>> spectra were generated using SBIG's Spectral Calibration Program.
>> Resulting
>> graph is at:
>>
>>
>>
>> http://www.tinyblue.com/user/Reveal_Incandescent_bulbs.gif
>>
>>
>>
>> David Trowbridge
>>
>> Tinyblue Observatory
>>
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>
>
>
>
>