Newtonian Collimation using the OCAL collimator

If you own a Newtonian I think this is an essential tool to ensure your image train is in line with your secondary mirror. The visual representation of the concentric rings allows for an extremely accurate collimation.
My images suffered with Star Flare and focus issues. Since using the OCAL my images have an extremely flat field and no gradients.

[@HerbsGarage]

Finally a guy that knows what he's talking about ! Well done.

[@nebulosityireland]

Thanks 👌🏻

[@joedenisco6033]

Excellent video. And your M45 pic in the end is proof positive that this Collimator works. Great instructions. Thank You. Joe D

[@nebulosityireland]

Thanks Joe. 👍🏻

[@user-pi5xu7qs7n]

Very nice. Never considered to screw the ocal into the image train. I was getting small flares on one side of some of stars with my Newtonian. Turns out the secondary was off a little. Never noticed it when just using the ocal by itself mins the image train adapters. Thanks a lot.

[@nebulosityireland]

You're welcome thanks. 😉

[@ScrapYardDog64]

This is what I found on one of my Newtonians but not on my MAK, My conclusion is my Newt focuser is knackered. Thanks for sharing, I guess you need a new focuser also 😁

[@nebulosityireland]

Yes I think the focuser included is cheap as chips which caused so much torture.

[@haiderbhogadia4829]

Excellent many thanks

[@nebulosityireland]

You are welcome!

[@tamartin7001]

Great, although the bright light is distracting, better to just point the OTA at the ceiling - the camera seems pretty sensitive to light - thanks for this, I just ordered the OCAL for collimating my 6" RC

[@nebulosityireland]

Absolutely, whatever works. I just found that the center spot and outside of the mirror was easier to see with the light. Its worth flicking between for accuracy. Clear skies. ;)

[@nordmende73]

Thank you!

[@joeshmoe7899]

Just did first collimation on sky watcher 200p. The laser was good for gross alignment of primary mirror, but not much else. Even after extensive collimation of the laser. Had to improvise a collimator cap to finish. Too much slop in the laser/focuser system. The laser may be going back.

[@qwertyu2387]

Am I right saying that this method and this device can be used instead of laser collimator?

[@nebulosityireland]

Apologies, only seeing this now. Yes that's correct, this replaces a laser.

[@stefanjagger]

The blue circle is slightly off center to the black background near it. I thought this would mean it needs adjusting. Does it instead need to just center on the red / white reflection of the camera? Good video, thanks for sharing.

[@nebulosityireland]

Hi, Yes, this is characteristic of a fast newtonian and is expected. The goal is to find the centre of the primary mirror, Centre the secondary in the primary, Then, center the camera in the secondary. Ultimately creating a centred reflection path. Hopefully, it makes sense. Thanks, Aaron

[@nebulosityireland]

There's an illustration of this about half way down this page on cloudy nights. www.cloudynights.com/topic/635284-collimation-of-a-fast-newtonian/

[@stefanjagger]

Hi Aaron. Thank you. That makes sense.y secondary on f2.8 looks elongated is this normal or do I have some tweaking to do? Will check out the link. Thanks, Stefan

[@jpro747]

I got it collimated perfectly and then rotated the ocal within the focuser tube, locked it back in and it was off 😕

[@jpro747]

I think it could be due to centre offset, unless it is at 0 if you rotate the ocal it will look off. The laser verifies thar collimation is correct

[@nebulosityireland]

@@jpro747 Hi, I'll test it with mine later. Does it happen if you just screw the camera or turn the entire image train?

[@jpro747]

Turning the entire image train 180 and locking in again

[@jpro747]

Ok, it’s definitely the center offset that’s causing the confusion. I checked this by reversing the center offset values and the circles match up

[@nebulosityireland]

@@jpro747 That makes sense alright. Good to know too. Thanks.