Baader MPCC users help needed

[toryglen-boy (Duncan)]

Howdy

So i bought a Baader MPCC from a forum member, i thought it might come in handy, my dob is F5, and i intend at some point on getting a 16" that is F4.5 so you can why i thought this would be handy.

It arrived this morning, in perfect condition, and on time and it was a hassle free sale, i 'spose the point i am trying to make here, is that there is nothing wrong with the MPCC for defo.



So whats my problem, can i get any eyepiece to focus with this fitted?

no.

It seems to move focus ever so slightly, which means when using a meade 26mm plossl, there just isnt enough travel outwards, and when using anything from a 15mm onwards, there isnt enough travel inwards to get it to focus, probably due to the 1.25 adapter and MPCC stuff. if i wanna use a 20mm all my life then i am in heaven.

I have tried this on two crayfords, that is two slightly different models, both from 12" dobs and cant get it to focus at all.

Has anyone else experienced this? or am i gonna ahve to buy another focuser, probably low profile, with extensions tubes

[acropolite (Phil)]

Duncan, there are specific spacing requirements for the MPCC, you may need some extra spacing and fine tuning rings, if you don't have one already, I suggest you download the manual from here

[toryglen-boy (Duncan)]

Originally Posted by acropolite

Duncan, there are specific spacing requirements for the MPCC, you may need some extra spacing and fine tuning rings, if you don't have one already, I suggest you download the manual from here

yeah fella, been working through that, and i know i have it all setup as meant to be.

I have a kinda work around solution, by pulling the MPCC assembly by about an inch, it seems to work

[RobF (Rob)]

I've found mine very handy for imaging, but must confess haven't tried to set up for visual. Believe it moves focus outward slightly (for prime focus photography) which is handy on newts.

[Satchmo]

For visual use the only way to use it is to buy the correct spacing rings and screw it onto the eyepiece, which then becomes a unit which goes into the focusser as normal... Thats how Wayne was using it and why you got all those spacing rings, which may or may not suit your low power eyepiece..

Check the Alpine astro website for list of all the rings required for various eyeieces. You don't don't want to use it for high powere observation as it induces Spherical Aberration on -axis, which is not going to effect prime focus photography

Mark

[toryglen-boy (Duncan)]

Originally Posted by Satchmo

For visual use the only way to use it is to buy the correct spacing rings and screw it onto the eyepiece, which then becomes a unit which goes into the focusser as normal... Thats how Wayne was using it and why you got all those spacing rings, which may or may not suit your low power eyepiece..

Check the Alpine astro website for list of all the rings required for various eyeieces. You don't don't want to use it for high powere observation as it induces Spherical Aberration on -axis, which is not going to effect prime focus photography

Mark

Hi Mark

As stated i know its all setup right, with correct spacing etc. i know its fine, and just me being an idiot. but it does appear to shift focus. I have the rings, and i ahve them spaced correctly, i know this as i can get an image, if i move the MPCC assembly out of the focuser its a very nice image to!

[Satchmo]

Originally Posted by toryglen-boy

Hi Mark

As stated i know its all setup right, with correct spacing etc. i know its fine, and just me being an idiot. but it does appear to shift focus. I have the rings, and i ahve them spaced correctly, i know this as i can get an image, if i move the MPCC assembly out of the focuser its a very nice image to!

You might need to get a 2" OD extension tube..I think Bintel sells 35 and 55mm ones pretty low cost. I had a quick look at the alpine site..doesn't mention how much back focus the combo needs.

[toryglen-boy (Duncan)]

Originally Posted by Satchmo

You might need to get a 2" OD extension tube..I think Bintel sells 35 and 55mm ones pretty low cost. I had a quick look at the alpine site..doesn't mention how much back focus the combo needs.

yeah that was my guess to, its fine just now, and i have a workaround.

i guess this is an excuse to buy a fancy new focuser