Jupiter 14th Dec

[legion48]

GRS and Io's shadow.

8 inch Newt, DFK21 and x4 barlow

1300 of 3000 frames.

[Jarvo]

Nice image - lots going on here..............

[Clayton]

Nice shot Tony:)

Looks like your final f ratio is about f10.5. I'm not sure why the 4X isn't giving you more (some barlows do strange things with a camera on the end??) I think you could see improvement if you increased the f ratio to at least double (low f20's or more)

I know this is easy to say, and I'm not certain I can give you good advice, but perhaps a 5X Barlow might be worth exploring (any helpful friends willing to let you try one )

[Clayton]

Whoops :rolleyes: Where's the edit button when I need it

That f ratio should read f17.6

Which is about right I think for the SW?? So maybe an extension tube (made from an old Barlow) would suffice

[Glasspusher]

Very nice, a lot to see in that image, well done.

John

[legion48]

Thanks guys.

Clayton, I have a decent x2 barlow but doubling it with the x4 powermate gives an image that is too dim. I'm toying with the idea of getting a Tal x3 barlow to double up with?