My take on the helix

[johnnyt123 (John)]

HI all

This is Narrow Band capture of the helix.
Taken last night.
Cloud cover was very bad. had to dump many of my subs

HA: 3x 1000sec subs
SII: 3x500sec subs
OIII: 5x 200dec subs.

blended HA Luminance, Red: HA, Green SII, Blue OIII

All stacked in CCDstack2, manually aligned in Photoshop CS6

All feedback welcome. I am still a nooby to LRGB.

Thanks
John

[RickS (Rick)]

Doesn't look too bad, John. Shame you lost a lot of data. The stars are a bit blobby. How are you focusing?

[gregbradley]

A great start there. Helix is quite dim.

Not sure what you mean by manually aligned in PS6. Normally you would register (align) your master images (the already aligned and combined images from the same filter to form a master) and save them. Then open the already registered (aligned) masters in PS. PS for some reason does not have an align tool - don't know why - its quite an omission from its toolbox.

Also a good source of how to process narrowband is at astrodon.com under tutorials on using clipping masks to make a narrowband image. Its probably the best technique for narrowband.

Greg.

[johnnyt123 (John)]

Hi again

Rick I focused manually using A bahtinov mask with the Ha filter.

I realise that the astrodon narrow band filters are not par focal as they claim to be. The Ha stars were really tight. But the SII and OIII stars were not focused. The OIII was the worst..so will have to refocus between filters.

Greg by manually aligning them I mean after stacking the Ha,OIII and SII subs separately, when placing the RGB data in PS6 the stars did not line up. I had to manually move each channel and rotate each channel until the overlay looked right. It still wasn't 100% and it's really difficult to do. If you zoom in on the stars at the periphery you can see that the channels don't exactly line up.

What I don't know how to do is how to align the master stacked Ha,OIII,and SII so that when I paste them into PS6 RGB channels they line up perfectly without me having to do anything. I know I am still not 100% with my polar alignment and get a little field rotation.

I should also mention that I didn't take any dark, bias or flat frames here.

Thanks again

John.

[TimberLand (Justin)]

John,

I use Nebulosity and in that you can do a registration without stacking and keep the files aligned but separate I know Pix Insite can do this but I'm not a fan of slow Java based software for number crunching.

That way you have a set of images all aligned and you can do other things like statistical weighted stacks to remove wild card CCD errors and also have the files aligned very well for LRGB in photoshop.

[RickS (Rick)]

Originally Posted by johnnyt123

Rick I focused manually using A bahtinov mask with the Ha filter.

I realise that the astrodon narrow band filters are not par focal as they claim to be. The Ha stars were really tight. But the SII and OIII stars were not focused. The OIII was the worst..so will have to refocus between filters.

That's probably the cause of the bloated stars, John. "Parfocal" is really just a marketing term. There's always some difference in focus between filters. Whether that matters depends a lot on how fast your optical system is (filters that are close enough at f/9 may not be at f/5...)

Originally Posted by TimberLand

I know Pix Insite can do this but I'm not a fan of slow Java based software for number crunching.

PixInsight processes are all written in C++ and generally seem to work very efficiently on modern multicore/multithreaded systems. Some of the scripts, like BatchPreprocessing, are written in Javascript but they don't do any serious "number crunching". Javascript, despite the name, has no relationship to Java...

[TimberLand (Justin)]

Sorry Rick I don't mean to have a go at good software as I have used and enjoyed PixInsight when it ran on both of my systems but the stability was my main issue. The speed could be improved a bit, but I understand keeping something cross platform is a challenge My two systems are quiet different and the annoying thing for me with PixInsight it is just faster on the workstation and crashes regularly on the bigger machine. And yet all my other software does get quite a kick along out of the bigger machine. If it would run as fast as I would like it to and not fall over then I would rave about it as it is fantastic processing software and gives amazing results. I know I'm asking a lot from the Pleiades group but at least testing it to run well on common high end machines would make the software for me a very worthwhile purchase.

My first machine is a Windows box on an Intel i5 with 4Gb of ram basic desktop.

The second is OSX on a 12 core dual processor Xeon workstation with 12Gb EEC ram and solid state hard drives.

So you see my frustration.

Justin.

[RickS (Rick)]

Justin,

I'm only using a quad core i7 (Windows 7) but PI gets all 8 threads hammering away most of the time. It also manages to use most of the 24GB of physical RAM on really large stacks when I bump up the integration buffer and stack sizes.

I can understand your frustration if you're having crashes and performance issues. Fortunately, I haven't run into any issues like that in a couple of years of using PI.

Cheers,
Rick.

[TimberLand (Justin)]

Rick,

Thanks for the prompt I have just done some digging on the new version of PixInsight and I might be renewing my licence. It has been year or so since I gave it a run and I see the the two main crashing and slow downs I experienced on OSX seem to have been addressed.

Sorry John for hi jacking the thread a bit off topic but maybe it has helped my setup improve as well thanks all.

I totally agree on the para-focal claims though I have used Meade, Orion, Baader and lastly Astronomik filters which have all been "para-focal" and whilst close to the same focal change they are not quite equal even on the f10 systems at work.

Justin

[johnnyt123 (John)]

No worries guys. I Need a processing program too and it's good to get first hand insight as to which may be better.

Here is the helix reprocessed with the same data.

Blending:
L: Ha
R: Ha
G: Ha + SII
B: Ha + OIII

Levels, curves and aligned in Photoshop CS6

It looks a bit better. I think thats the best i can get out of the data i have.

Just one thing i dont understand with pics saved under CS6.

When i save a pic with CS6 and view it with any other pic viewer there is a lot of imformation that lost. all the detail is only seen when the file is opened in CS6 again.

The first 2 pics are jpg's saved in CS6. pics 3 and 4 are sceen shots of the pic in full screen mode in CS6 then pasted and saved as a JPG in ulead Photoimpact which seems to preserve the images details. Even if saved as .tif the same problem stands.
Does anyone know why this is?

John

[Ross G]

Hi John,

A very good capture.

Wow!...RGB..you're moving and learning at a great rate.

Good luck.

Ross.

[johnnyt123 (John)]

Hi Ross.

Long time no hear.

Yeah have decided to take a step into LRGB. images look so much better, but it is a steep learning curve.

I think i main problem is patience. I feel like i need to image with all the filters in the one night. But as you will learn with astrophotography patience is a virtue and the more patient you are the better our results are.

I am starting to think of maybe upgrading to WO FLT132 stepping up from the Megrez 110. What do you think?

John.