M57 and M45 6.10.10

[Carole]

Had to take advantage of that clear night on Wednesday.

Both modded Canon DSLR 450D CLS filter and WO Flattener, guided on WO Megrez 72 APO
Stacked in DSS

M57 - 10 x 5mins (I think I neeed to do this again with a barlow), hardly any post processing


M45 - 17 x 5mins - POST Processing in Photoshop (and same focus as M57)

[Mac]

(I think I neeed to do this again with a barlow)

and a focus mask.

M45 is good.

The focus is defiantly  out on the ring.

[MarkS]

The Pleiades have come out surprisingly well for a light polluted location.

M57 is a tiny object - try M27 instead - that would come out much better.  
You also have some chromatic aberration - either that or it was very low in the sky?

The stars are slightly elongated which indicates that your guiding might be slightly off.

Mark

[RobertM]

The M45 is quite impressive for your location, well done.  Guiding is definitely off on M57 though, especially noticable as you've cropped the frame and zoomed in.  It would be interesting to compare the guiding on the two images.

Nice job of processing too.

You must be quite satisfied with that nights work.

Robert

[MarkS]

Yes - I agree with Robert - they're very nicely procesed!

[Jim]

Well done Carole, you're really getting there. I use a Batinov focus mask which makes focusing easy

[Carole]

Thanks every-one and I agree with your comments on focus and guiding.  I did use a Bahtinhov mask and the spoke looked dead central.  Tried using Luminosity and Bahtinhov grabber (as per Mark's help and tuition) but for some strange reason I could not get the focus star to show up in Luminosity and yet it was dead central in Canon Utility, Canon camera, 800 ISO, 1 frame per second all checked - weird.

I had the same focus on both M57 and M45, so I guess the fact that M57 is so small and I had to zoom in so much, showed up any slight inaccuracy.  So yes, the ring was a bit disappointing but thought I'd post it anyway, just to show what I am doing.  

Yes, guiding I am concerned about as a few months ago with the same set up I had no problems at all, and all the stars were nice and round.  But the last few images the guiding has been off.  I have set the agressiveness to 0.02 so not sure what is going on there.  It's ironic really because when the guiding was working OK I often used to get a chiming noise from PHD to say the SNR was low, but now not getting that and the guiding is crap.

Any suggestions or thoughts on this.  Not yet done a drift alignment on my mount since I had to put it back on the mount as there have been so few clear evenings, but will do it a.s.a.p.

You also have some chromatic aberration - either that or it was very low in the sky?

NO it wasn't.  Oh dear.  

You must be quite satisfied with that nights work.

Thanks Robert. I am quite pleased with M45, but I know there are problems that need getting to the bottom of and always room for improvement.  

Carole

[MarkS]

 I have set the agressiveness to 0.02 so not sure what is going on there.  

Set the aggressiveness back to its default of 100.  In fact set all parameters back to their defaults.  That should provide a good starting point.

Chromatic Aberration - was M57 central in the field of view or off at the edge?

[Carole]

Chromatic Aberration - was M57 central in the field of view or off at the edge?

It was almost bang in the middle.  Oh dear it gets worse.

The joys of imaging both + and -

Carole