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magnification...
Hi Chris - with a 130mm scope you aren't likely to ever use more than 250x and that even rarely, in nights of extremely good seeing (like once in a blue moon.)
The general rule says 2.4x the aperture in mm - meaning theoretically with a 130mm scope you could get up to about 300x, but realistically 200x-250x would be the limit, and then only rarely.
Don't want to be a downer but that's the truth, if you bought a 3x barlow it'd only ever be used with the 20mm ep - a 2.5x barlow with your current eps would give you magnifications of 50x 100x 125x 250x which would leave a gap that something like a 12mm ep could fill somewhat, with approximately 83x and 200x - much more likely to be used.
A barlow does increase eye relief, lessening the need to "surgically remove" your eyeball from the ep when used, if your ep's don't have good relief.
Bintel stock 2.5x GSO barlows that are quite reasonable for normal circumstances, I have one that I use quite regularly even though I've also got a TeleVue 2x as well.
Check out other threads in IIS to get other opinions also: btw couldn't see any dot/star in your image of Saturn, but Titan is very easily seen under low power. Hope this helps, Darryl.
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