Just attempted secondary collimation for the first time, how have I done?

[pipnina]

Hopefully I should get a short while of clear sky tonight, so in preparation I decided to try my hand at secondary alignment on my 130-PDS

As far as I can tell, I have the mirror aligned rotationally correctly, but it seems the mirror is not quite in the center of the focuser (this is 2" focuser but 1.25" cheshire so that maybe amplifies effect) I'm not quite sure how to bring the secondary back slightly to correct for this however.

Is the oval shaped shadow natural for a correct alignment of F5 newt? I have read in some places the effect can be seen but I'm unsure whether this is right.

So I suppose the ultimate question is: if this were your scope, would you be content to image with it in that state?

 

Thanks

[carastro]

The central black area can be lop sided as you have it with a fast Newtonian, but the primary mirror as you say does not look central, and you should be able to see the 3 mirror clips, so doesn't looks quite right yet.

Carole 

[Skipper Billy]

I think you are quite some way off yet - have a read here, it's one of the best collimation guides I have read. Just take it one step at a time. Good luck!

http://www.astro-baby.com/collimation/astro babys collimation guide.htm

[Doc]

I agree you need to adjust your secondary to get the three mirror clips of your primary mirror into view. This is best done with a collimation cap. You might need to undo the centre screw on the secondary mirror and move the whole lot and once all three clips are visible tighten the centre screw.

[alacant]

Hi. There maybe a little loss of light toward the side where you can see daylight -toward the top and left as you have it in your photo- but the primary looks good. Clear sky tonight so If I were in your position...

1 hour ago, pipnina said:

would you be content to image with it in that state?

... has to be a yes!

[pipnina]

51 minutes ago, alacant said:

Clear sky tonight so If I were in your position...

It's out there right now!

I bodged the polar alignment and I have college tomorrow so I will have to bring it in at 11:30 sadly... But I did my 3-star alignment and the polar alignment error was about 20 minutes. Tried a 30 second image on mizar which looked very good, and currently taking 1 min subs of M51.

Here's hoping it comes out good for a first show

Thank you all!

[Ricochet]

2 hours ago, pipnina said:

I'm not quite sure how to bring the secondary back slightly to correct for this however.

Back off all three outer secondary screws and then tighten the centre screw. 

[david_taurus83]

I have had my focuser off at the weekend to paint the drawtube so I've had to re-collimate as well tonight. I use my guide camera, flats panel and Sharpcap with its reticle to centre everything up. I had to remove the spring from behind the mirror to bring it back far enough to centre under the drawtube but still managed to align the primary quite well. Proof will be in the pudding as they say!

[pipnina]

I think we have a reasonably successful first light!

40x1 mins of M51. Lots of hot pixels sadly but I can't help them in a DSLR :/ CCD is next bit of kit I think, though I will have to start saving!

And a 30-second exposure of Mizar A&B and alcor.

And brighter edit:

 

Seems a good start to me, especially given the moonlit condiditions! Hopefully we get some more clear skies in the coming weeks

Thank you all again.