[ATM] Difraction Spikes

[Lawrence D. Lopez]

In fact the secondary causes a diffraction ring which can under certain 
circumstances make it easier to see a properly position double star.
At leaast that is what I heard about Questar's.

Can anyone verify this ?

Jeremy Royston wrote:
> Hello Jack,
> 	With a normal width spider it will have hardly any effect on the
> image quality - probably less than 1% of the light goes into the spikes.
> It's only possible to see them near bright stars against a dark background,
> so with an extended object like Jupiter they'll be almost invisible.
> The curved spider with semi-infinite width round the mirror has a larger
> effect, and the diagonal itself.
>
> Best wishes, Jerry
>
> -----Ursprüngliche Nachricht-----
> Von: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] Im Auftrag von
> Jack Swaton @ Starry Host
> Gesendet: Freitag, 30. Oktober 2009 05:24
> An: 'ATM List'
> Betreff: [ATM] Difraction Spikes
>
> 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?
>
>
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