Barlow Focus Issues

[Neon]

As part of my master plan to use 2" eyepieces in my 80mm Sentinel (Z80 clone), I recently purchased a 2" diagonal off of Ian. I'm really pleased with the diagonal, mainly due to it using compression rings, so it's definitely a 'keeper'. However, when I try using my Meade Shorty barlow the images won't come into focus since there isn't enough inward travel.

I was observing the moon last night and my guess is that if I had less than a centimetre more inward travel on my focuser it'd work.

So does anyone have any ideas how I can get it working, or will it be a case of buying a 2" barlow to match?

[philsail1]

Hello "Neon."

You say you need just about a centimetre more travel to achieve focus?

If the barrel on your diagonal is long enough, you could try easing it out of the focus tube on your scope and locking it in its new position, then trying to focus. You could also try easing the eyepiece back a centimetre or two then locking it.

Just ensure everything is securely locked.

I know it's not the ideal solution but I've done it and found its worked.

There may be other ways of achieving focus - I'm sure others on SGL will soon help!

Regards,

philsail1

[Neon]

Cheers Phil,

Problem is though it it's the inward focus rather than the outward, like I need a shorter scope, and this one's pretty short already!

I'm guessing it might be time to buy a 2" barlow instead, unless anyone's got any suggestions.

Cheers

Mark

[philsail1]

Oh! I see.

Hmmm, I think you'll have to see advice from someone a bit more knowledgeable than me on this matter Mark.

Have you thought of contacting Steve from FLO?

Best wishes,

philsail1

[RichieP]

I have the same issue with a ZS66, which doesn't have enough inward travel to use the Meade shorty Barlow. The Meade series 4000 apo 1.25" barlow works fine though, so I assume its to do with the shorty's design.

[Neon]

Cheers Richie,

Sounds like it might be time to upgrade my barlow. The 'shorty' type are quite handy, but if they won't work with short tube scopes and 2" diagonals I reckon I'll try out a different design.

Thanks

Mark