Newbie in need of assistance..

[Who is John Galt?]

Hello SGL. Long time fan, 1st time caller

Last year I was bitten by the astro bug and after a few months stargazing, I've felt inclined to try a bit of astrophotography (I blame all the posters of those fantastic pictures uploaded to this site) and I've hit a slight snag already.

I own the skywatcher 200p and I am having trouble achieving focus using filters. Prime focus is fine using my digital SLR and t-ring, but as soon as I try to add an adapter (Standard adapter with scope) for the filters I can't get enough inward travel.

I've checked some advice given to other users with the same issues on this site, for example, moving the mirror further up the tube; I tried this, and unless I'm doing something wrong, which I'd be happy to admit, I still can't seem to get the eyepiece close enough. I've tried moving the mirror as far as the threaded bolts will allow.

I've read an alternative is to buy a low profile focuser. I've tried to do a bit of homework and know of the crayford from FLO, but it does state a minimum of 9" tube. Does anyone know if this would work with the 200p without heavy modification? This is the black skywatcher not the blue type if that makes any difference.

Is the focuser the only option I have?

Any help is appreciated

Many thanks

Lee

[Geno]

For some reason the adapter I have with my 200P is not threaded so i bought this one which i use with a SW LPF with no problems. My 200P is the newer type black one, I use an EOS 550D and can achieve focus with no issues.

I too would like to upgrade my focuser when funds allow to a dual speed focuser so would be interested to know if the SW fits the 200P.

[Viv]

I had exactly the same problem.

Try using a barlow.

[Who is John Galt?]

Thanks for the replies.

I'll try the barlow, but I'm at a loss as to how that works? Wouldn't that just magnify the out of focus image?

Thanks

[Viv]

Thanks for the replies.

I'll try the barlow, but I'm at a loss as to how that works? Wouldn't that just magnify the out of focus image?

Thanks

The way it was explained to me, a barlow doesn't maginfy the view, it doubles the focus.

But - i'm not arguing - it works !!

[brantuk]

A barlow extends the focal length and in theory takes the focal point backwards a bit. But you'd have to do the numbers for your scope/barlow combination to work out how much back focus you need and where the focal point will be to make it work.