Datalord

On 07/06/2019 at 11:05, MarsG76 said:

A long time on exposure but worth the wait and exposure time... the image is smooth and detailed....

 

Thanks. You can find the final one here, where all the help materialized:

Tomorrow I'm heading to Spain to switch out my CGX for an ASA DDM85. I would not recommend the Celestron for long focal length setup, as the mount simply isn't good enough. I will bring it back and use it for my RASA @620mm, for which it is great, but definitely not for an 11".

YMMV

On 05/03/2019 at 11:04, Astroscot2 said:

Can I ask what intervalometer you used for taking your frames ?

When I used my 6D, I bought a cheap one on Amazon. They are very simple and work well. https://www.amazon.co.uk/s?k=intervalometer+canon+6d&crid=3L2SRCXPQYHPO&sprefix=intervalometer%2Caps%2C178&ref=nb_sb_ss_i_6_14

As you can tell from that search, they are essentially all the exact same, with different branding. Probably made in the same factory in China.

Ok, I think I'm done with this one. With considerable help from @vlaiv, @wimvb and @ollypenrice in the threads below, and what amounts to at least 20 hours of processing, this is my final Iris.

Lum core problems: https://stargazerslounge.com/topic/336149-eternal-issue-of-blown-star-cores/

Acquisition details and colour problems: https://stargazerslounge.com/topic/336220-23-hours-lrgb-on-the-iris-nebula/

3 minutes ago, wimvb said:

But why you would want to move it into PS is beyond me.  

I really wish I didn't have to, but I just feel like I have more control over the final bits, especially sharpening and noise. I know the tools in PI are exceptionally strong, but it lacks the fine tuning I can do with a brush and layers in PS.

2 hours ago, wimvb said:

Place a few samples distributed over the entire image and save an instance of DBE. Then apply this instance to the linear original image.

God bless PI's history and ProcessContainers. I did as you suggested and got to this. Before I move on to repeat all the PS work, I'd like to check if the right honorable gentlemen approves:

1 hour ago, wimvb said:

Great image. 23 hours well spent.

At running the risk of being the party p..per. There is a strong colour gradient across the image. DBE would cure that. But setting the samples is a bit of a challenge.

Yeah, I've been through quite a few iterations of DBE in the colour images. The problem is that I literally have only this non-nebulous area:

I'm willing to go through it all once more to try to control the DBE better, but I'm afraid of killing the detail. Another thing I actually did look at was other Iris pictures with a wider field, to see if this particular section should be a different colour and it seems like the blue is inherently stronger on that side:

34 minutes ago, ollypenrice said:

The upper right is somewhat magenta. Could this have arisen during an application of SCNR Green?

definitely a possibility. I applied it quite late in the process, so reverting that should be easy. Before going back, I tried doing a tiny colour balance adjustment in PS towards green and red in a selection of magenta. Better?

After quite a bit of work on this data I'm pretty happy with it. Comments and suggestions welcome.

Gear:

• CFF 12" RC
• G3-16200
• Celestron CGX
• Baader LRGB filters

Acquisition

• Lum: 20*20 min bin1, 19*10 min bin2
• RGB: 26*10 min each bin 2
• 22h50m

Processing. PI and PS. A lot of it.

Ok, I think I found a way that somehow manages the luminance blowout without causing too much mayhem. Essentially I truncate the blown out centers by applying a curve to the lum value above a threshold. I'm reasonably happy with the result when merged to my colour image, so I'll move forward with this. Left is the processed Lum, right is the truncated Lum.

@vlaiv, I think your method holds merit with the colour normalization, I just can't get it working on this particular set. Thanks for helping me move this one forward. 

Hmm, that got me closer, but I feel like this is something where I skip over a lot of steps and chances to do tiny adjustments before the stretch, which simply isn't possible doing it like this. This is where I got to, still with lots of issues:

I have uploaded the combined colour file, which has been through DBE, background neutralization, colour calibration and SCNR.

RBG_ColourCalibrated.fit

21 minutes ago, vlaiv said:

For this to work, your color channels need to be white balanced already

But, how do I do that? White balancing works on the entire colour range. I usually do PhotometricColorCalibration on the combined color image.

What I could do is to process the colors combined, then split them and go through this procedure?

3 hours ago, vlaiv said:

Now comes mixing part. Take normalized color image and split into L*a*b* channels. Normally one would discard L channel, but we won't do that in this method.

Take color part L and multiply with stretched luminance. Result is new L that we will use. Now just recompose final image with this new L and a and b channels from color part and convert back to RGB.

Something here is beyond me.

I have all the maximum and division and combination done, which gets me to this:

Extracting CIE lab gets me 

Multiplied L with my processed Lum:

ChannelCombined back it becomes: 

Blown cores and this is even without any form of stretch in the color space at the time of combination. Don't I have to apply the normalized color to a combined color image before applying any Lum?

Ah, cool, thanks! Easier than all the stuff I was thinking about. I'll give it a try. 

46 minutes ago, alan4908 said:

Repaired HSV separation on the unstreached RGB image

I've been playing with that today, but grief ensues when the resulting RGB image is grey and flat and very little information about why can be teased out of it.

1 hour ago, vlaiv said:

Hope that all makes sense.

It really does. Now the problem is to figure out how to do this normalization in PI. The only part I can't just do in PixelMath is the "Maximum stacking method", which I have no clue where to find.

Thanks Alan, that's very tangible advice. I looked over my pre-stretched picture and the cores are above .9 in both lum and color. I have some narrowband I had a test with, which might work well for starfield and core, so I'll try that.

So, I'm processing the Iris nebula. I have most of my color, 13h of 10 min RGB. Still ticking away on a few more hours. I have 10 hours of Lum in 20 and 10 min.

So I started setting up all the processing and got carried away. Led me down the path to this.

The problem is the star cores and it comes from the lum side when I blend it in. 

The problem almost always comes in the MaskedStretch, which is both great and horrible. It controls the outer parts of the stars beautifully, but I always end up with blown cores. 

Does anyone have a golden advice for me on how to get this stretched without blowing it up?

I was very seriously considering a CEM120EC before buying an ASA DM85. But only the EC version. I think those encoders are worth it knowing all the trouble guiding can give you. (disclaimer: Still haven't tried imaging without guiding, but I spent a ton of money getting to that point...).

Welcome to the hobby. As you can tell already now, the money sinkhole is opening beneath you.

I would very strongly encourage you to fully separate visual from imaging. Don't try to make a visual setup good for imaging. I went that way on a NextStar 6 with an alt-az, buying wedge and adaptors and blah blah, only to 6 months later flip the table and buy a small refractor. I made it work for what it could, but it was a waste of money.

IMHO, cancel your order of a wedge and buy the star adventurer. If budget allows more, use it all on the best mount you can afford. Use a regular lens and plan your first upgrade to be a filter drawer and NB filters. With such a setup you can go nuts in large nebulae and learn the processing skills, which in the end will take you at least as much time to master as the the data acquisition. Going really deep to galaxy hunting is where your money will disappear at astonishing rates.

On 11/04/2019 at 18:41, AstroBobG said:

Yup, it does support the AVX mount.

And with the latest beta update it is really, really good. The previous versions didn't implement ASCOM, but now it is a great piece of software.