[ATM] Quirky idea

[greycoyotee at yahoo.com (Grey Coyote)]

Howdy

I am indeed refering to focal length of the eyepiece.

Thanks!
-R
--- Royston_Jeremy@emc.com wrote:
> Hello Rob,
> 	I think what you mean is: 
> Magnification = focal length of the objective /
> focal length of the eyepiece
> The magnification doesn't change when you change the
> eyepiece aperture
> 
> If one has a CCD instead of the eyepiece, one cannot
> speak of magnification,
> the only thing which changes with the CCD size is
> the field of view, which
> is about 57.3 * CCD size / objective FL degrees 
> 
> Best wishes, Jerry
> 
> -----Original Message-----
> From: atm-bounces@atmlist.net
> [mailto:atm-bounces@atmlist.net] On Behalf Of
> Grey Coyote
> Sent: 04 February 2004 14:48
> To: The Amateur Telescope Makers List
> Subject: Re: [ATM] Quirky idea
> 
> 
> 
> Howdy
> 
> Call me Rob, please. ;O)
> 
> I may actually be using the wrong terminology here.
> What I am using for magnification is focal length of
> the telescope, in my case 750mm divided by the
> aperature of the eyepiece, say 12 mm. So that
> particular eyepiece delivers 62.5 power. A 5.1 mm
> eyepiece with the same scope yields 147 power. A 3mm
> eyepiece with the same scope yields 250 power
> 
> Commercial ccd's like starlight are at 3 mm and 5 mm
> aperatures. I have a
> spreadsheet a friend got off the web that shows
> optimal viewing for large
> nebulas is 48x. Optimal viewing for globulare
> clusters is 180x. That's a
> wide range. To go from 250x to 180x with 3mm one
> would need to use a focal
> reducer with the ccd. 
> 
> My idea is if one could fashion an array of ccd
> chips
> say 2 across and 2 deep that would be around a 4mm
> aperature which would yield 187.5x with my scope of
> 750 mm focal length.
> 
> Some people out there have way more than 750 mm
> focal
> length ;O) Say 2100 and above. These people would be
> able to use a larger array say 4 across and 4 deep.
> That would be about 8mm maybe as much as 10mm in
> aperature. The sensitivity would be much greater
> allowing deeper than mag 13 objects. One would want
> focal reducers for stepping power lower. 
> 
> This really may be out of step for small time
> scopes.
> *shrugs*. Just tossing this out and seeing if
> someone
> has thought of this or done it before.
> 
> Thanks!
> -Rob
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> --- Vladimir Galogaza <vladimir.galogaza@zg.tel.hr>
> wrote:
> > Gray,
> > 
> > It seems that I do not understand well your idea.
> > Where exactly will you put CCDs in hypothetical
> > refractor.
> > At the focus or else?
> > 
> > What do you mean by: "Magnification is still focal
> > length /
> > aperture."
> > Usually this is quoted as "power" or "f- ratio"
> > or "f number".
> > 
> > Regards
> > Vladimir.
> > 
> > Outgoing mail is checked by AVG anti-virus system 
> 
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> > Date: 2/01/04
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> > 
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