NGC6888 with C9.25

[ianaiken]

Here is NGC6888 captured through my C9.25 and Atik 460EXM with ASA 0.77 reducer.  11x600s 2x2 Ha, OIII and SII.  It fills the entire frame of the Atik.  I certainly want to add to this next year.

[Mr Spock]

Superb images. I really like the second one, it shows up a lot of fine detail in the outer edges.

[laudropb]

Very nice images. Lots of nice detail. Thanks for posting.

[swag72]

A good demonstration of what the C9.25 can do when everything is working well together - Having done it myself with a C9.25 this is testament to your perseverance. It's tough going for sure, but doable

[wavydavy]

_{Is the third pic sii filter??}

[morimarty]

Some great detail in these long focal length images Ian, you have clearly picked up the outer OIII shell region really well. I also see you used the asa reducer/flattener, a bit slower than the celestron 6.3 but IMO a big step up in quality?

[toxic]

very nice indeed Ian very nice control not letting the front shock wave burn out and still getting the finer detail well done.

[ianaiken]

Thanks everyone for the feedback!

Sara when I first did M51 with a test of this reducer I was blown away in all honesty just to what could be achieved.  If only the C9 was the EDGE variant but nevermind.

The SII filter was used but each process is a combination.  The first is HA and OIII with tiny bit of RGB I took.  The rest are different combinations of HA, OIII and SII.

The ASA is a step up IMO too to the 6.3 although this is reflected in the price too.  The stars in the corners are no worse than not using it.  On the plus side, the whole ASA reducer and extensions fits nicely inside my Baader Diamond SteelTrack which can only help especially when the dSLR is connected.  Distance to chip for the ASA is 97.5mm.

[graemlourens]

Absolutely mindblowing how close up details you could get. Beautiful picture. Got my own coming up soon stil processing...

Mind if i ask what your Total RMS was while guiding? At this focal length it would be interesting for me to know.

Kind regards, Graem

[Astroscot2]

Nice detailed crescent -  well done imaging at that focal length.

Mark

[ianaiken]

Absolutely mindblowing how close up details you could get. Beautiful picture. Got my own coming up soon stil processing...

Mind if i ask what your Total RMS was while guiding? At this focal length it would be interesting for me to know.

Kind regards, Graem

Hi Graem,

It's brilliant I've always imaged fairly wide and earlier this year when I had my first go at M51 on this setup I was blown away.  I'm afraid I don't recall but is probably not a good indication of good guiding anyway.  What I know is that it guided very well through an OAG on my EQ8 and I did the calculation to ensure I knew what the max error could be to ensure tight stars.  Any star deformities seen is likely from collimation, which isn't too great on the scope at the moment.  The guide graph looked horrid but that's due to focal length.

Are you imaging it wide or narrow?

PHD settings were:

Dither = both axes, Dither scale = 1.000, Image noise reduction = 3x3 mean, Guide-frame time lapse = 0, Server enabled

Pixel scale = 0.43 arc-sec/px, Focal length = 1810 mm

Search region = 40 px, Star mass tolerance = 50.0%

Equipment Profile = C9.25

Camera = CMOS QHY5LII Camera (ASCOM), gain = 95, full size = 1280 x 960, have dark, dark dur = 5000, no defect map, pixel size = 3.8 um

Exposure = 5000 ms

Mount = EQMOD HEQ5/6,  connected, guiding enabled, xAngle = 80.6, xRate = 16.463, yAngle = -9.2, yRate = 15.626

X guide algorithm = Hysteresis, Hysteresis = 0.150, Aggression = 0.800, Minimum move = 0.500

Y guide algorithm = Resist Switch, Minimum move = 0.500 Aggression = 100% FastSwitch = enabled

Calibration step = phdlab_placeholder, Max RA duration = 2000, Max DEC duration = 2000, DEC guide mode = Auto

Here's that first M51 image:

[Chris]

Great work! It must have been hard just finding the object on the chip, net alone imaging it to such a good standard

[graemlourens]

Hi Ian.

I'm currently on 1.84 arcs / px so very wide i my PHD2 graph can look like mount everest and you'll not see too much in the image.

Thx, were you on the EQ8 for this image?

I'd be very interested in your guiding graph for any of you're sessions where the results were 'round stars'. At this imaging scale its very tough

Regards, Graem

[ianaiken]

Hi Graem,

I was indeed using the EQ8 guided through an OAG.  The graph was like a mountain range but the movement was less than needed to impact the stars.  DEC balance was off too which I think helped.  At the moment the mount has the C9.25 and two refractors mounted so it may be a while before I get a guide graph from the C9 as the Atik is on a faster refractor at the moment.  I could however use excel if you really really wanted to see it as I have the guide logs still.

Hi Chris,

I used Sequence Generator Pro and used the plate solve function.  This meant that it could centre the image within a few pixels of where I wanted to be :-)

[graemlourens]

Hi Ian.

Thx, its ok, don't need the logs, just was wondering

Yesterday i got constant guiding at 0.5 arcsecs, with a 1.86 resolution massive overkill, but already practising for the big guns

PEC made a massive difference i must say with the AZEQ6.

P.s. SGP is also my tool of favor, and platesolving works great, even if sometimes i just an not get rid of the DEC pixel error (around 180px), evn if it resyncs few times, it just does not get better. grrrr, so automatic multitargets in a night is always a luck thing... I know 180px is really acceptable, but with a smallish chip it hurts still

Regards, Graem