Deneb vicinity, a bit of a teaser

[minimalist]

This is part of an ongoing mosaic I'm doing of the Cygnus area. I plan to do the area around Sadr next (you can see some of it here), then more around this area, maybe even get the Veil in.

A total of 8hrs in 20min subs, taken through the Canon70-200f2.8 at 70mm and f5, modded 1000D at iso400. Not totally happy with the procesing, but I'll try better when I do the mosaic.

Hope you like, critique most welcome.

http://2wcg2g.bay.livefilestore.com/y1puPLySxfFsz7rjnpex3MmZlUXk0ddGkt6402U-SWDM9dEVRz7E5_cqze4PXo2pLK37oRB9VBC3r2hdHCZyuBNY8ey_UacNWtr/Autosave_crop.jpg

Daniel

[ncjunk]

Sorry Daniel can´t come up with anything constructive on this one. It looks fantastic.

Neil C

[Aza]

Crikey that is some piece of work so far. Can really see where the 8 hours have gone in to it

8 hours at this time of year is pretty dedicated.

The final mosaic should be awesome!

Colour could be better balanced but otherwise the processing is well done.

Looking forward to seeing the final mosaic.

[Beyond_Vision]

Tracking and focus are spot on and the detail is superb. I would agree with Arran on the colour balance the bright star to the left of NGC7000's 'mexico' region should be yellow everything is biased towards the red. Looking forward to the mosiac

Regards

Kevin

[minimalist]

Thanks all, much appreciated. Yup, color balance is my nemesis, I have yet to get the right star colors no matter how hard I try. Without the CLS filter, no problem, but with it on I'm totally lost. If anyone knows the secret to balancing an image taken with the CLS filter and modded dslr, I would be very much in their depth. I tried all sorts of settings in DSS; tried balancing on a known yellow star (like the one mentioned) and got very funky colors for the rest of the image. I'll keep on trying though. Looks like the CLS filter really kills the green.

I did find out one techinque that partially works. I used Noel's select brighter stars, then used the minimum filter on the red channel to reduce the red in those stars. It gives a lot of them a bit of a cyanotic tinge, but a closer balance to the true color. I'll post a redo a bit later today to see what you think.

Thanks again, I very much appreciate the critique and suggestions.

Daniel

[Psychobilly]

Very nice indeed... Satarted something similar back in June but i am imagign through a Megrez 72 FF III so 345.8mm FL so need a lot more panes...and hence more PAIN!! I have only got 3 nights on it... havent had a chance to add anything more to it yet

I'm "lucky" in that my LP can be knocked back with a Hutech IDAS P2 and I get much better colour balance with it than with the CLS-CCD that I use in the 2nd DSLR...

Peter...

[Aza]

I use a CLS and DSS, and use this technique to balance the colours during stacking.

Have you tried it yet? For me it seems to work well enough, as I also have trouble finding a good balance without it.

After clicking 'Stack checked pictures' in DSS, click recommended settings.

In that section you can scroll down and ensure you use the option that says:

"If the colour balance in the resulting image is hard to fix......."

Also if you have Nebulosity, there is a similar option in there which can be used after stacking.

[Deneb]

Wow, thats a beautiful picture.

[Starstrike]

That is a superb view of the upper cygnus region, looking forward to the final mosaic. Processing is always the bug bear, but persistence pays off! If its any help I used an astronomic cls filter on my North American Nebula on this site imaged with an unmodded 1000d. I stacked in DSS then tried balancing the colours there. It was biased to the red still. In PS I paritially desaturated the image and adjusted magenta and the red in the colours option, it seemed to do the trick. Good luck. Paul

[minimalist]

Thanks all for the comments.

Peter, yup, I hear the Idas is much better with color balance, I may actually save my pennies and buy one for comparison. My lp is moderate, so I think if I use the Idas I can knock out the remaining LP in photoshop without mucking up the colors. I have to say we have been blessed with cool clear skies here lately, makes long sessions a lot easier (unless I screw up).

Arran, yup, that's what I use now, it causes DSS to do an all channels balance instead of per channel. I tried different channel multipliers too in the pre procesing section, no luck. I think there may be a combo of those multipliers that works, but I haven't found it.

Paul, that is a good tip, I haven't use the color balance dialog in a long time, I may need to play with it again.

In the meantime, a reprocess where I tried to reduce the red in the brighter stars. Not sure how much better, which one do you prefer?

http://2wcg2g.bay.livefilestore.com/y1pC258_FSDT7t7zMQaVHXCHRSZQNyqnC-IkVOpAMJuqh17STP-_LzkWWdeqi35JaOW-zQGY4sjsDVpjSGxgYaqwQ/Autosave_crop2.jpg

Daniel

[Tim]

The picture is great. Perfect focus and tracking.

Some DSLR 'experts' like Jerry Lodriguss recommend shorter subs with higher iso. 20 mins seems a long time for a non cooled chip to be performing. Still, the result is good.

I have a modded 350D, which I use with a cls filter. The subs come off the camera a little bluey.

When I get the stacked file out of DSS, I open it in PS, then go to the levels tool. You will probably see by selecting each colour that the channels dont line up/overlap each other very well. So By clicking CTRL+1 I set the black point slider for the red channel, CTRL+2 for green etc. This brings the colours into balance for me, and then process as normal.

If certain areas like stars still look odd, the selective colour tool can be very useful.

Cheers

TJ

[minimalist]

Thanks for the kind words and the info.

I used to do the shorter subs at high iso, until I saw the noise curves on dpreview.com. Iso 800 and up, the noise goes up faster than the signal, resulting in more noise and lower dynamic range.

I have no choice when imaging with the RC, the f9 ratio requires those long exposures. I found that with the faster lens, iso200-400 works really well when using the cls filter in the light path, as it cuts down about one stop of signal. The other thing I usually struggle with in summer is heat induced noise, and unfortunately iso800 has horrendous noise at 80+F.

Not to say that I couldn't be wrong on this. I'm still very much learning even after all these years.

Daniel

[Trevorw]

This is very good, nice crisp stars, plenty of detail, you may be able to stretch the curves a bit more,

VGE

[Starstrike]

Like the latest rendition. It shows the profusion of hydrogen in this region. Paul

[steppenwolf]

This is an really exciting image. The colour balance however is a little too far to the red but this can be corrected as can the slight colour gradient from left to right. I am really looking forward to seeing this image progress.

[minimalist]

Thanks all for the comments. Steve, I definitely agree, the second one is way biased towards red... in my haste to show the hydrogen clouds hidden in there I think I overcooked it a bit. I also just noticed the lower right corner has been reduced a bit too much (I had a bad gradient there).

I just read your message and saw the reprocess, very much better than mine. What did you do? Especially the star colors. I don't know if it's appropriate in this forum or not, but I think a repost of that image you sent me plus a quick explanation of the steps might help others like me who struggle with colors.

Thanks again folks. Btw, just finished the Sadr area subs, another 8hrs (yep, not much sleep lately), so I want to get this processing right before I start putting the mosaic together.

Daniel

[steppenwolf]

Hi Daniel,

As requested, the following image is my rework with an explanation of the steps carried out:-

The following was carried out in PhotoShop

1. I produced a duplicate layer

2. I used the 'lasso' selection tool to carefully select every bit of nebulosity I could detect

3. I inverted the selection and used Russell Croman's Gradient Xterminator in 'medium' to resolve the gradient that traverses the image from left to right. This also gave an overall better colour balance to the image

4. Using 'levels' I gently adjusted the red channel using the centre slider to decrease its brightness a little

5. Finally I use the 'curves' tool with a gentle adjustment of the centre off to the left to get a slightly more 'pink' rather than red nebulosity colour

[minimalist]

Fantastic Steve, and many thanks for taking the time to write the steps out. Funny thing, I used the trial version of xterminator about a year ago with good results, but for some reason never bought it. Well, looks like it's a good idea to do it now.

Well, the mosaic will have to wait a bit till I get this processing lark figured out better. I tried to blend this and the new Sadr panel, but so far it's, as you guys put it, pants.

Stay tuned...

Daniel