Questions about a barlowed laser

[Horwig]

I'm considering getting my home built truss imaging Newtonian to a better state of collimation. So a few questions before I spend any more money.

Trouble is, the scope has no draw tube as such, instead there's an OO Wynne corrector running in the focuser.

Till now I've been using a sight tube which replaces the whole focuser, Wynne and baseplate assembly to collimate, but I've no way of knowing how close it is to the actual focuser position and alignment. So, question is, can I use a laser THROUGH the Wynne corrector?

Read a post where a laser was used through a Parracor, and this diverged the laser somewhat like a barlow, would a Wynne work the same?

If I still need a Barlow, I have a TV Powermate x5, could this be used?

I could just go a out and buy a cheap laser, but I'd rather know what I'm letting myself in for first.

Huw

[John]

Hi Huw,

A Powermate won't work for laser collimation because it does not defocus the laser beam, it keeps it parallel.

I don't know anything about the Wynne Corrector's but if it has optics within it then I reckon it's better to use star testing to collimate the scope rather than a laser because the optics in the corrector could distort the laser beam.

[cs1cjc]

A newtonian is perfect on the optical axis so any corrector should have a null effect there.  Accordingly  the corrector should not impact collimation.

[Horwig]

Nothing beats experimentation!

Last night I had a thought, I have a green Laser pen, wonder if it could be used (bodged) to prove the system, and guess what...

This is the rig:

Collimating the laser pen to shine down the optic axis was a pain, not sure if the result means anything. Wonder if it's worth while getting a cheap laser collimator to test? Will do a star test, that is, if we ever get a clear sky again.

[cs1cjc]

I realise that my reply above is nonsense.  Correctors  generally have some magnifying power so will  disperse a laser beam.

Apologies