Spikey Stars

[robindurant]

I keep on seeing images on the forum which contain spikey stars. How do you get the spikes

[GazOC]

They're called 'defraction spikes" and are caused by the light hitting the vanes attaching the secondary on Newts.

If you see them in images taken with a SCT or refractor it means they have been artifically added after the shot using software.

[gsjag]

How come you (supposedly) don't get D'spikes with Ritchey-Chrétien designs and I see some Ritchey-Chrétien with vanes and some without?

Gary

[GazOC]

How come you (supposedly) don't get D'spikes with Ritchey-Chrétien designs and I see some Ritchey-Chrétien with vanes and some without?

Gary

If you see them in images taken with a SCT or refractor (or any other scope design that doesn't use a spider) it means they have been artifically added after the shot using software.

[OXO]

Some of the images you see on SGL use Noel Actions for Photoshop and there artificially created..

James

[gsjag]

Thanks guys. I thought you got defraction spikes from SCTs as well.

Gary

[OXO]

You can also make diffraction spikes by placing say fishing wire over the front of the tube(Not optics) in a X shape..

[anthony]

I get my diffraction spikes on my refractor with a little wire cross hair thingy. It helps to confirm focus and you can rotate it to get a more aesthetic orientation to the spikes.

Ant

[moondog]

Now I know what to do with my old guitar strings !

Thanks for the tip.

I'd seen the spikes on Rog's images with the ED80 refractor and thought they must be artificial.

Spikes can make the larger, brighter stars look more interesting - if not overdone.

8)

MD

[anthony]

Now I know what to do with my old guitar strings !

I was thinking the same thing. I'm going to try a nylon G first. When I get round to it and the skies clear I shall post my results. Previously i had used the wire from inside a thin electric cable but this was quite tough to keep straight.

Anthony