Another Lulin...

[JohnP]

Not very exciting but I got it.... Didn't set up till 12midnight due to clouds so only did a few quick exposures. 12X2mins with Atik16ic through zs66 - it was a lovely night though...

This image was stacked using comet core (hence star trails).. I should be able to put together an animation when I get a chance.

Wasn't going to bother setting up only that Mike said we wouldn't be able to see it for another 40,000,000 yrs......

John.

[Mike]

Nice one John!

[Fay]

Well done john.  I was going to do 90 secs subs, will I get star trails?

[JohnP]

Depends what you guide on & what FOV you are imaging with...?

Since both my scopes are on fixed rings I cannot vary them independently of one another - they point at slightly different areas of the sky so when I had the comet in my imaging scope I couldn't see it on my guide scope. Had I been able to then I would have guided on the comet nucleus - since I couldn't I guided on stars.

When I stack if I select stars for alignment then stars are pinpoint but obviously comet looks a little elongated. If I choose comet nucleus when I stack (which is what I did) - comet is correct but you end up with the dotted stars - you can count the individual exposures that I made.

Hope that makes sense - John

[RobertM]

That's excellent John, I can see the prospect of having to wait all that time got you out in the freezing conditions  It's good to see it's movement in time lapse (much better than my effort).  What was the interval between shots ?

[Fay]

JOhn, Gregg & Noel have produced a fantastic comet on UKAI. They also explained the implications of stacking on stars or comet.

[JohnP]

Fay - Yep I just saw that - it is very good but cheating slightly (I think) ... I guess what they did is produce two images one stacked with comet & one with stars & then superimposed... I could be wrong...

It is an excellent image thought & I love the background galaxies that they've got in the tail..

John

[JohnP]

Thks Robert... I must admit I very nearly didn't bother.. takes me at least 40mins to set up & starting at 12 midnight was a big effort... Feel crap this morning after 3 1/2 hr sleep...

I will try & put the animation together later..

John

[Fay]

Yes, I think there is definitely a boundary with processing that when going too far, it just proves your efficiency in PS, & it can alter the basis of what you have taken & what you end up looking at.
Images are getting better & better, so we have to keep up with new processing ideas otherwise our images will all drop behind in being aestheticly pleasing.

I don't agree with going too far, but can't help admiring an image that has been taken too far off course of reality

Does that sound muddled????

I've put the bottle down!

[JohnP]

Yep Very.......! What was in the bottle...? John

[Fay]

 

[JohnP]

Fay - This is what Greg/ Noel did to get their excellent image:

Regarding the several questions on stacking...

We used the SDMask form of stacking for the star-aligned version, which (given that the comet is moving rather fast) yielded an image with some of the antitail showing but the comet head virtually eliminated.  We couldn't have planned that better!  A second stack, on the comet nucleus itself, yielded a nice, sharp result for the head/coma, and combining the two in Photoshop using the last sub processed separately as a guide for where to put everything yielded the result you see here.


John

[Rocket Pooch]

Well done John, I gave up at 11pm because there was some high cloud, maybe I should have kept at it and not slept..

I like the little dots for stars

[JohnP]

It really cleared up by 12 & was one of the best nights I have seen from Bromley for a long, long time... I should have stayed up & done something else but I had to be up at 5.45am...

John

[Rocket Pooch]

Typical and I had to work