An unsatisfacry NGC1333...

[Rush]

I could download, Choose direct download from dropdown menu, it works. are Tiff files.

Rush

[wimvb]

Yes,

right click on the link, copy the address and paste in a new tab/window. This opened Dropbox and made direct download available.

Thanks Rush

And Olly

[gnomus]

Hi Olly

Have you got them in a Public folder on the Dropbox and have you got the download links by pressing the 'Share' button?

[Stub Mandrel]

8 hours ago, gnomus said:

If a passage of music is marked "quiet", yet when you listen to it, the recording engineer has made it "loud", then it jars and is out of place.  If a cloud of faint dust is thrust down your throat by an overenthusiastic processing job, then it also jars.  Can you imagine if Rembrandt's paintings had had the 'Shadow/Highlight tool' applied to them, so that all of the chiaroscuro was lost?  Not that I'm comparing you to Rembrandt .....  well .....   You must excuse me, the medication hasn't kicked in yet. 

I find many 'HD' images suffer from this far more than astro images.

[wimvb]

Downloaded and playing with your image, Olly.

I'm not used to (L)RGB processing, so it may will take me a while. There's also so much dust that finding background to extract is going to be a challenge.

I will probably use the technique we discussed here earlier, and use your processed image as a reference.

Thanks for sharing the data.

[Barry-Wilson]

Don't be too self-critical Olly.  This is a lovely image and if I was to contemplate an enhancement it would be to increase the contrast in the dust stretching towards vdB13 (I think).  This is a fine balance though as the swathe of molecular dust doesn't have a defined 'edge' and its density will decrease and feather to nothing to a degree.

You know all this of course, just don't make it too hyper -PI'd, LOL 

[swag72]

I like this and it has certainly given me some ideas for a target should I feel particularly masochistic!! I've looked at this at length and I'm trying to put my finger on it.... It feels just a little flat, I'd like to see a bigger difference in the background and the dust... Is there any way that the background can be selected and then the balance changed from the red, perhaps a little towards the blue? Just a thought and something I'd be trying.

I do think you've been hard on yourself though... this is a lovely image

[ollypenrice]

1 hour ago, swag72 said:

I like this and it has certainly given me some ideas for a target should I feel particularly masochistic!! I've looked at this at length and I'm trying to put my finger on it.... It feels just a little flat, I'd like to see a bigger difference in the background and the dust... Is there any way that the background can be selected and then the balance changed from the red, perhaps a little towards the blue? Just a thought and something I'd be trying.

I do think you've been hard on yourself though... this is a lovely image

Thanks, S. I agree with your critique but the problem is how to address it. I have tried everything I can think of. The flatness you see here has been de-flattened by every means I can think of!

Olly

[sharkmelley]

I've downloaded your data and begun to play with it.  I'm seriously impressed by what you have managed to pull out of that data.  Part of the reason may be that I'm not familiar with LRGB processing. There's an up/down gradient in the RGB data and a left/right gradient in the luminance.  Looking at the RGB data it might be difficult to pull the subtle variations in hue above the noise threshold.

I don't want to hijack your thread but if you (or anyone else) wants to play with my data as a comparison, you can download the (linear) TIFF from here:  https://drive.google.com/open?id=0B3Ky5pyZvsINRW90Tzh3dkZ5aFE  (hit the downward arrow to download).

It is 3 hours of total integration time.  I've already given it an iteration of PixInsight DBE.

Mark

 

[wimvb]

The main problem I'm having with this image is the background extraction.

It seems ok, but after stretching the RGB data, the dust looks like a rainbow.

I'll continue during the weekend, as we're clouded in anyway. (Someone in the neighbourhood must have bought a major piece of astro-gear)

[sharkmelley]

I agree with Wim - the big problem is extracting the gradients.  I did a DBE in PixInsight followed by dealing with some of the residual gradients in Photoshop.  It still needs more work though.  I've only processed the RGB data and not the Luminance.  I'm on familiar territory when dealing with RGB

After dealing the gradients all I did was a background stretch followed by noise reduction.

Mark

[gnomus]

Olly - you win.  I still cannot 'walk on the rice paper' without tearing it.

[wimvb]

Grashopper, how did you remove the gradient? (Now that we're referring to 70s series.) 

[gnomus]

11 minutes ago, wimvb said:

Grashopper, how did you remove the gradient? (Now that we're referring to 70s series.) 

You need to perform the following steps, very carefully.

1) Realise that one should generate the sample points using the Lum image

2) Think one is clever and do a 'Hyper-STF' of the Lum image

3) Understand that this creates such confusion, that one needs to return to a normal STF

4) Start placing sample points

5) Realise the sample points are too large (they are still covering stars and dust), so reduce the sample radius

6) Start placing the reduced-size points

7)  About 10 minutes in, realise that there is so much dust that it is becoming impossible to tell at zoom 2:1 what is dust and what is background.

8) Abandon steps 1-7

9) Run ABE using default settings

10) Hope no-one asks how you removed the gradient.

[wimvb]

1. Check

2. Check

3. Check

4. Check

5. Check

6. Check, I actually adjusted sample size according to distance between stars

7. Check

8. Check, several times

9. Ah, the ever reliable 'old Abe'

10. I only asked because I couldn't find this checklist in Kellers book.

[johnrt]

Some very nice processes above.

So here is my version, firstly I do really enjoy processing, and it's a real pleasure when you can get your hands on someone else's data to play with, especially when the data is top quality "Les Granges stuff"!

My first task was to also flatten out the Luminance using DBE, I simply adjusted tolerance to 0.8 and let it generate samples wherever it liked at the default size, 2 rounds of DBE and straight out of PI in to CS5. RGB was also combined in PI, DBE (as above), background neutralisation, hard log stretch, SCNR green and in to CS5.

I have included a link below to my .psd file of the image with most of my processing layers intact, the background layer at the bottom has just had some curves and levels applied, the only layers not present are some tweaks to the colours and saturation (which I assume we all know how to do) and some tiny cosmetic touch ups. Layers coloured red simply combine all processing adjustment layers below them in to a new layer. There was a bit of despeckle and high pass sharpening on the luminance and noise reduction on the RGB in there somewhere too.

I recently watched this tutorial on pulling out faint dusty signal from Scott Rosen, http://www.astronomersdoitinthedark.com/Bringing-Out-the-FaintStuff.php which has some great tips in for processing just this type of image.

Anyway, I hope I've done it some justice!

 

 

https://dl.dropboxusercontent.com/u/65773776/LUM 1333_reg_cp.psd

 

John.

[Rush]

Forgive me Olly, if mistreated ur lovely image

Cheers

Rush

 

[ChrisLX200]

14 minutes ago, Rush said:

Forgive me Olly, if mistreated ur lovely image

Cheers

Rush

 

Vandal!

ChrisH

[ollypenrice]

Great fun folks! Thanks for all the play time you've put in. John, I very much like you charcoal colour scheme. Steve has it, too. I always fall prey to the temptation to render dust more visible by redenning it. It looks as if Mark's right about the depth of the RGB though. It probably just doesn't go deep enough to pull out the colour variation.

Maybe the sky wasn't very good for the colour but I just can't remember. It's at least two and a half years old, this data. The red stars are not great, giving a red overlap in many cases.

We had massive thunderstorms all night and a total village power cut. When I went into Laragne for shopping this morning I looked down at a small stream that runs through it. It was a raging torrent with standing waves and the water was exactly the same milk chololate colour as my image with exactly the same flatness and opacity of colour!

Olly

[Rush]

 

Thanks for the fun and files

Clear skies

Rush

[gnomus]

7 hours ago, johnrt said:

...

My first task was to also flatten out the Luminance using DBE, I simply adjusted tolerance to 0.8 and let it generate samples wherever it liked at the default size, 2 rounds of DBE and straight out of PI in to CS5. RGB was also combined in PI, DBE (as above), background neutralisation, hard log stretch, SCNR green and in to CS5.

...

Interesting.  I normally spend ages making sure that the generated DBE points are not on any structure.  I delete some points and move others around.  It can be time-consuming.  I tried your technique and got something very similar to my ABE result.  

Some folks have dug out an awful lot of dust and this prompted me to have another go at this - pushing the data as far as I feel able to manage.  This is probably way too much, though:

[ollypenrice]

22 hours ago, swag72 said:

Please delete. I can't get rd of this box!!!

 

[Stub Mandrel]

This is my first serious play with multichannel data, so please excuse...

[Stub Mandrel]

Weird - it looks better uploaded. All my own pics look worse... have you nobbled the forum software to favour your pics Olly?

[ollypenrice]

Sorry about the post above but I get this a lot with quotation boxes. It is purely an IT thing and has nothing to with Sara.

I think that if you let DBE do its own thing, as John describes, then that is likely to be much the same as ABE, no?

I see that everybody is getting red-rimmed stars, which is clearly a fault of the data. Hangs head in shame.

I'll have to speak to Dr O'Dononghue to see if we are going to re-do this blighter. He cannot be blamed for this data since it precedes the dual Tak setup we co-own. I strongly suspect that we are! I didn't post the 14 inch data but that does take care of the bright bits. Shame to waste that...

Meanwhile I feel I know where my homework needs doing, so thank to all.

Olly