Which spider vane ?

[nitram100]

Hi guys,

I'm about to order a new spider vane for my 10" Orion optics newt to replace the 2 vane world war 2 spider vane that mine came with, each vane is 1cm thick for crying out loud!

Barry at Orion Optics has offered me a 4 vane spider or a OO style spider, either for 50 quid, which one do you guys think would be better?

Thanks,

Martin

[russ]

I had a similar response from Barry regarding my 8" Orion Optics Newt. I asked him for info on the circular spider as they are better for planetary imaging. But apparently they were too difficult to make and were dropped.

The 4 vane spider looks very much like the standard Synta jobby with 0.5mm vanes. Should do the job nicely. Not seen the replacement OO option.

I was considering doing a re-coat on the mirrors at the same time. Perhaps with the Hilux coating.

Russ

[barkis]

The 4 vane will introduce diffraction spikes on images of brighter stars inyour pictures. These are attractive to most people, but others would prefer not to have them. Some are introduced artificially by software techniques. If you do not want them in your images, then go for the curved vane support. That way the dffraction is dispersed, and will not be seen.

A 3 vane one is a nono, as that will intoduce 6 spikes.

Ron.

[GazOC]

It might be worth mentioning that a curved vane will result in a slight loss of contrast across the whole field of view.

[nitram100]

cheers for the responses guys, i thought i would just add that i am a visual observer only, no astrophotography for me! sounds like the 4 vane would be a fail safe option..

Thanks!

[barkis]

cheers for the responses guys, i thought i would just add that i am a visual observer only, no astrophotography for me! sounds like the 4 vane would be a fail safe option..

Thanks!

You will still see them visually, but the good thing is, they can indicate that your collimation is OK.