WO66 : Help needed

[Catanonia]

Ok at my wits end with this mini scope.

I just CAN NOT focus ANYWAY with it at all.

It is the white WO66 doublet F5.9 version of the scope.

I have tried the following.

1. Focusing with a SCT 2inch adapter with an 2inch EP with and without a 4inch long extension tube. NOTHING Full range.

2. With a Skywatcher diagonal, SCT converter and with and without 4 inch extension with 2inch EP NOTHING full range

3. All above combinations with a QHY5.

Everything works, as can move to the ED80 and get perfect views with EP etc.

I have tried as much outward focus as I can possibly do about 1 foot extra and the bare min I can get inward and nothing.

What is it with this scope. So far my extensions with EP have been as long as the f'ing scope itself with the dewshield extended.

Surely this is not right....

HELP

[Catanonia]

mmm, searching around seems this scope is very diagonal depend upon the WO diaelectic type diagonal other wise massive amounts of outward are needed.....

http://www.iceinspace.com.au/forum/showthread.php?t=19374

DANG !!!!!!!!!

What a pain of a scope....

[ollypenrice]

Just a matter of finding the right distance, I think. It sounds as if you might be too long or two short and need to be in the middle.

For visual use I find the SCT 1.25 back and a star diagonal (or erect prism for birding) comes to focus withought extensions since the diagonal or prism adds what is needed.

For imaging I use a dedicated flattener reducer but for guiding I don't so I have taken a measurement. From the front of the scope with the dewshileld pushed back in its storage position to the chip is about 42 cm. I can only say 'about' because I don't want to take off the guide camera and lose my settings (we are in mid project) but if you get your chip somewhere near 42 cm back from the front of the scope then you should be in the ball park.

Hope that is of some help.

WO are obsessed with shortness and end up with whacky extensions inducing grief of various kinds...

Olly

[Catanonia]

mmm, thanks Olly.

I will give it another go this time with the QHY9 attached via the 2in SCT adapter and see if I can get focus with and without the 4 inch extension tube.

I noticed that when I prime focused the QHY5 on my ED120 it went back a long way, but with the OAG and QHY9 attached, the distance was MUCH shorter on the ED120.

Maybe this will help on the WO66 as all reports seem to be that without a WO Diagonal, you need ALOT of back focus.

Will check your measurements too, but pretty sure was over 1/2 metre away lens to chip last night.

[ollypenrice]

I think you'll find 42cm is quite a way back. I use a de-lensed old barlow body to add a bit.

Olly