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[vsnet-chat 5748] Re: ST7E + photolens
- Date: Tue, 24 Dec 2002 09:15:55 +0100
- To: <vsnet-chat@kusastro.kyoto-u.ac.jp>
- From: "Ondrej Pejcha" <opejcha@volny.cz>
- Subject: [vsnet-chat 5748] Re: ST7E + photolens
- Delivered-To: vsnet-chat-archive@ooruri.kusastro.kyoto-u.ac.jp
- Delivered-To: vsnet-chat@ooruri.kusastro.kyoto-u.ac.jp
- Delivered-To: vsnet-chat@kusastro.kyoto-u.ac.jp
- References: <6EFE35AB.57DFE5B9.0A8B1A31@aol.com> <009301c2aaba$4cba1e20$6edc4cd5@r4t3m6>
- Sender: owner-vsnet-chat@ooruri.kusastro.kyoto-u.ac.jp
Hi guys!
Sometimes, a ST-8 is attached to a photo-lens here at Brno
observatory. Focusing is done by hand and is quite difficult
because ST-8 readout times are long and you have to go a
long way from the telescope to the computer. Although focus
can be reached, achromatic and apochromatic lenses are
corrected for colour aberration only at visible wavelengths.
Thus, unfiltered CCD will show stars as big blots and redder
stars being blots more than the blue ones. This could be
quite annoying. Enhanced SBIG chips might give better
results. Despite all this, photo-lens CCD photometry can
give very good results - guys from Johan Palisa observatory
are succesful contributors to VSNET with ST-7 and small
photo-lens.
Merry Christmas and happy New Year to everyone!
Ondrej Pejcha
Return to Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
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