Another collimation issue thread

[Tyr]

Good evening all,

I've been having an issue with collimating the 150p I recently picked up in the FLO clearance.

I tried following Astrobaby's guide and also the orion video on youtube. But I've run into a problem.

At the end the process the view in the cheshire appears to be correct (based on images from AB guide) as follows:

3 primary mirror clips visible at the edge of the field of view

Little dot (reflection of the center of the cheshire?) inside the the little center circle on the primary

Cirlce with dot in the middle under the cross hairs (as best I can tell they are a blur to me) of the cheshire (not the spider viens).

However when I try and point the scope at a star the only thing I can see a tiny floating image that looks like a reflection of the primary / secondary / spider arangement I see when looking through the cheshire or colimation cap, moving the focuser in an out makes the image larger and smaller.

Any ideas where I could have gone wrong?

Tyr

[Starlight 1]

Is the eye lens in the focus tube ,with no more tubes in the line

[Tyr]

I'm sorry I dont quite understand the question.

I'm not using a barlow or an extention tube of any kind.

Just a 2" to 1.25" adpater (this one http://www.scopesnskies.com/prod/GSO/revelation/accessories/t-thread/eyepiece-adaptor.html)

And a 25mm eye piece, which should give me a magnification of about 30x and an exit pupil of about 5mm. I thought this is longest FL eye piece I would want to use.

Tyr

[Starlight 1]

Its this part of your post,(moving the focuser in an out makes the image larger and smaller.) I see this alot like this when you try to fit more tubes, that will give you not enough inward focus.

[Moonshane]

Good evening all,

I've been having an issue with collimating the 150p I recently picked up in the FLO clearance.

I tried following Astrobaby's guide and also the orion video on youtube. But I've run into a problem.

At the end the process the view in the cheshire appears to be correct (based on images from AB guide) as follows:

3 primary mirror clips visible at the edge of the field of view

Little dot (reflection of the center of the cheshire?) inside the the little center circle on the primary

Cirlce with dot in the middle under the cross hairs (as best I can tell they are a blur to me) of the cheshire (not the spider viens).

However when I try and point the scope at a star the only thing I can see a tiny floating image that looks like a reflection of the primary / secondary / spider arangement I see when looking through the cheshire or colimation cap, moving the focuser in an out makes the image larger and smaller.

Any ideas where I could have gone wrong?

Tyr

Am I right in thinking you are saying that you cannot bring the image to sharp focus at all with your 25mm eyepiece? If you cannot then it sounds like you are either using both the 2 and the 1.25" adapters. you should only ever use one at a time I think with these focusers.

[Tyr]

I think I worked it out. I went back down stairs to look at the scope again.

I realised that if I extended the focuser as far as it would go, then took out the EP and held it about an inch from the tube that the image came into focus as a star.

And that the 2 to 1.25" adapter was seated too far into the focuser tube, so I extended the light path a bit by moving the adapter a bit further out of the focus tube.

I'm not sure if I should need to do this or if I've messed up the primary mirror adjustment in some way, could having whole mirror too far forward cause the same effect? is it even possible to do that by accident?

Tyr

[umadog]

I doubt you've moved the mirror that far forward. The springs don't have a lot of travel. So long as you can reach focus, that's the main thing.

[Tyr]

ok, it sounds like I can chalk this one up as solved to the extent I need to worry about then.

Thank you fo the help everyone.

Tyr

[knobby]

ok, it sounds like I can chalk this one up as solved to the extent I need to worry about then.

Thank you fo the help everyone.

Post a pic and we'll have a look!

Sent from my HD2Droid