Thick Spider vane

[nitram100]

Hi guys, a quick question.

I've been meaning to upgrade my 1cm thick single vane spider for ages now as it is just plain ridiculous, it came with my OO Europa 10" about 5 years ago, those of you with older OO scopes will know how hideous these things are. Question is, i'm going to America in a few weeks and am going to get some cheap gear including a spider, which one would you recommend?

http://www.fpi-protostar.com/s3vmnts.htm

http://www.fpi-protostar.com/s4vmnts.htm

http://www.1800destiny.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=1D&Product_Code=LCVS&Category_Code=CVS

http://www.fpi-protostar.com/crvmnts.htm

Also, could the 1cm thick single spider vane be responsible for the 2 long streaks of light which appear around the planets, they kind of make Mars and Jupiter look like Saturn.

Thanks for any advice!

[Ant]

I heard some good reports about the three vane curbed one.

http://www.1800destiny.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=1D&Product_Code=LCVS&Category_Code=CVS

So I think i'd seriously consider one of these. Almost competely removed spikes...

Ant

[iancandler]

I'd say curved is definatly the way to go if you dont like diffraction spikes.. and lets face it they can always be added in photoshop later if you want them.

[saturn5]

Yep i know what you mean about the girder vanes,i have an OO 6" with 2 vanes and it makes you wonder just how much of a light blocker they are.Your single vane is most definately responsible for your 2 long streaks,you always get one from the vane and another 180deg from it,so with 1 vane you get 2 spikes,2 vanes 2 spikes.3 vanes 6 spikes 4 vanes 4 spikes.

I'm sure someone with brains can explain why you get a spike 180 deg from a vane,diffraction yes but how?

[nitram100]

They are ridiculous aren't they? the OO vanes. I read that some guy on the orionoptics yahoo group filed his down to 1mm and had no problems, don't know if i'd want to risk it. Thanks for your explanation of the diffraction spikes. I've been reading about curved vanes the way they spread the diffraction throughout the whole view, while you get no spikes, you apparently loose a tiny bit of contrast and the 3 vane spiders 6 diffraction spikes are not as bright as a 4 vanes 4 diffraction spikes. Hmmm, choices choices!

Saturn5, i see you have a Skywatcher, they come with 4 vane spiders right? How bad are the diffraction spikes on the planets with a 4 vane?

Cheers mate

[saturn5]

Yes the Skywatcher comes with 4 vanes and although its weeks since i've been out because of the weather and even longer since i viewed a planet i can remember that spikes are not a problem.

Its a couple of years at least since i last used the OO 6" but i do remember back when Jupiter was well placed for observing that i didn't have any trouble with diffraction spikes.

Although i havn't measured the vanes on my scope i would say they are about 5-6mm so looks like your 10mm vanes are the problem,10mm must look really massive. :shock:

[russ]

I have the curved 3 vane jobby on my OO 150 and it's a big improvement.

Russ

[nitram100]

Thanks for the info

[The Warthog]

I've heard nothing but good about the curved vane spiders, both from those who've bought them and those who've made their own. I like the looks of that three vane jobby.

[philsail1]

Hello Nitram100!

I had a Skywatcher 130P Newt and I filed down the four vanes to about a millimetre without any trouble. They are only cast alloy. You only have to keep a careful look at how your filing is going - the metal is so soft that one could easily file through it.

After job was complete. I painted the clean metal matt black.

However, I cannot say whether all my hard work made that much difference really!

I would echo other's advice and go for the curved three vane job. (If you are going to the USA, and can pick up a Vane cheaper than in the UK, it would be a pity to miss the opportunity).

Best wishes,

philsail1

[nitram100]

Thanks for the info mate! I'm pretty sure that i will pick up one of the 3 vane spiders, but i'm also going to try filing down the existing spider, just for kicks 8)