[ATM] Difraction Spikes

[Peter De Baan De Baan]

What causes the 4 poined spike around brighter stars oncamera pictures made with refractor telescope ?

 baffled without the obsrtuction 

 

Peter
 
> From: richard1941 at gmail.com
> To: mjc5 at psu.edu
> Date: Fri, 30 Oct 2009 09:15:11 -0700
> CC: atm at atmlist.net
> Subject: Re: [ATM] Difraction Spikes
> 
> What if the spider vanes are relocated to the edge of the aperture, so 
> as th reduce the diameter? I think any reduction in aperture "blurs" 
> the image.
> 
> Consider, for a moment, the Allen Telescope Array-- it has huge 
> obstructions (the space between the dishes).
> 
> I apologize in advance for questioning dogma and trying to provoke 
> thought and fourier series. Note that i have long advocated piano 
> wire spyders and given up on Art Leonard (PBUH) technology.
> 
> Sent from Richard's iPhone
> 
> On Oct 30, 2009, at 5:52, Michael Coslo <mjc5 at psu.edu> wrote:
> 
> >
> > On Oct 30, 2009, at 12:23 AM, Jack Swaton @ Starry Host wrote:
> >
> >> Do diffraction spikes actually blur the object causing them? For 
> >> instance,
> >> is the view of Jupiter less sharp because of the spikes or the 
> >> thickness of
> >> the spikes?
> >
> > They tend to lower the contrast of the image, mostly through light 
> > scattering. And humans tend to interpret lower contrast as less sharp.
> >
> > -73 de Mike N3LI -
> >
> >
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