Jump to content

SkySurveyBanner.jpg.21855908fce40597655603b6c9af720d.jpg

An unsatisfacry NGC1333...

ollypenrice

By ollypenrice
in Imaging - Deep Sky

Recommended Posts

Barry-Wilson

Barry-Wilson

Posted
Posted

Just to add my tuppence worth - great data as we have all said and enjoyable to process.  One of my favourite targets without a doubt, it has everything a beautiful starfield, a reflection nebula, dark dusty tendrils, sparkles of red.

Thanks Olly.

Olly_NGC1333_LRGB.jpg

 

Link to comment
Share on other sites
  • Replies 84
  • Created
  • Last Reply
sharkmelley

sharkmelley

Posted
Posted

 

6 minutes ago, Barry-Wilson said:

Just to add my tuppence worth - great data as we have all said and enjoyable to process.  One of my favourite targets without a doubt, it has everything a beautiful starfield, a reflection nebula, dark dusty tendrils, sparkles of red.

 

Now that is an excellent result indeed.  I now know where to send my data :)

44 minutes ago, ollypenrice said:

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

 

If you find out what causes them, I would be very interested to know.  I get exactly the same on my Tak Epsilon and I've always wondered why.

Mark

Link to comment
Share on other sites
ollypenrice

ollypenrice

Posted
  • Author
Posted
23 minutes ago, sharkmelley said:

 

Now that is an excellent result indeed.  I now know where to send my data :)

If you find out what causes them, I would be very interested to know.  I get exactly the same on my Tak Epsilon and I've always wondered why.

Mark

It isn't at all normal for me, Mark. A bit of blue bloat to control, sure, that's normal. Maybe the seeing went off for the red. I prefer to say that than admit that I goofed on the red focus but, erm, maybe I goofed on the red focus!

Olly

Link to comment
Share on other sites
wimvb

wimvb

Posted
Posted

And here's my version.

I couldn't completely get rid of the colour variations in the dust. ABE reduced the colour content even more, so I went for a double dosage of DBE

As Olly already noted, stars turned out too red. I used Morphological Transform to reduce the red stars ever so slightly.

ngc1333_op_re.png

Link to comment
Share on other sites
ollypenrice

ollypenrice

Posted
  • Author
Posted

Hehheh, I ran it 1.5 times. Too conservative, I guess...

Olly

8 hours ago, StuartJPP said:

Some great processing going on here but so far Barry's result takes the prize...excellent stuff. People (myself included) could potentially save thousands in equipment cost by learning how to process their images like this...

I like Barry's best as well. However, compared with lots of versions out there my original moan (that the pure background and dust don't have much colour separation) still stands, so I guess it has to be an issue with the colour layer.

Olly

Link to comment
Share on other sites
Stub Mandrel

Stub Mandrel

Posted
Posted
1 hour ago, ollypenrice said:

my original moan (that the pure background and dust don't have much colour separation) still stands, so I guess it has to be an issue with the colour layer.

Corel Photopaint has a colour balance slider that you can choose to apply to shadows, mid tones and/or highlights. Perhaps it could help?

Deliberately overdone this is boosting the red in mid-tones (i.e. dust) only:

OLLY2.PNG

Link to comment
Share on other sites
Uranium235

Uranium235

Posted
Posted

Out of my comfort zone, but I though I would try my Ps background modelling and subtraction technique on it - almost got it right but not quite as the red channel still seems skew-iff, probably because each channel requires its own model..... perhaps I'll have another stab later on this evening:

ncg1333_ps_comp3.jpg

 

Link to comment
Share on other sites
wimvb

wimvb

Posted
Posted

I don't think anyone knows the answer to your question. In a reflective target, the perceived colour depends as much on the light source as the target itself. Add to that effects from the atmosphere and optics/camera, and you can pretty much end up with any colour you like or dislike. The only way to get to a good estimate, would be to do a spectral analysis from outer space. @FLOhas a tool for that on their webpage. It's in the clearance section :icon_mrgreen:

The best we can do is some kind of 'colour calibration' based on background and stars, and make s guesstimate.

The prettiest picture wins the prize.

Link to comment
Share on other sites
wxsatuser

wxsatuser

Posted
Posted
31 minutes ago, wimvb said:

I don't think anyone knows the answer to your question. In a reflective target, the perceived colour depends as much on the light source as the target itself. Add to that effects from the atmosphere and optics/camera, and you can pretty much end up with any colour you like or dislike. The only way to get to a good estimate, would be to do a spectral analysis from outer space. @FLOhas a tool for that on their webpage. It's in the clearance section :icon_mrgreen:

The best we can do is some kind of 'colour calibration' based on background and stars, and make s guesstimate.

The prettiest picture wins the prize.

Interstellar dust with no Ha emission ranges from dark brown through to orange, as the absorption increases.

If Ha emission is involved the dust gets redder depending how much emission there is.

Unless we know the make up of the dust it's a guess I suppose.

Would have thought careful colour calibration would reveal all.

Link to comment
Share on other sites
sharkmelley

sharkmelley

Posted
Posted
54 minutes ago, Rush said:

After initial hick mack, another go both in PI & PS.

There is a difference,  Seems colours are a bit crisper in PS and Pi is a bit rusty .

What is the natural colour of NGC 1333 ? Anyone ?

 

I think it is the background in your two examples that differs.  If you made the background more black in both cases then they might look more similar.

I'm not saying I know how to do that though!

Mark

Link to comment
Share on other sites
gnomus

gnomus

Posted
Posted
On 10/14/2016 at 10:42, johnrt said:

...

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.

...

That is some video at nearly 2 hours long!  Thanks for pointing me towards it.  I hadn't heard of many of those techniques before and will certainly be having a go at them.  Isn't Photoshop a versatile tool? 

Thanks again

Steve

Link to comment
Share on other sites
Rush

Rush

Posted
Posted
4 hours ago, wimvb said:

I don't think anyone knows the answer to your question. In a reflective target, the perceived colour depends as much on the light source as the target itself. Add to that effects from the atmosphere and optics/camera, and you can pretty much end up with any colour you like or dislike. The only way to get to a good estimate, would be to do a spectral analysis from outer space. @FLOhas a tool for that on their webpage. It's in the clearance section :icon_mrgreen:

The best we can do is some kind of 'colour calibration' based on background and stars, and make s guesstimate.

The prettiest picture wins the prize.

Is this a pretty picture RACE ? :) or evening classes for missed astro.P.science.

Natural colour really dont end up in my colour perception likes or dislikes.

All DSOs of various types, light emitted by gas, illuminated by glowing dust masses, lanes are seen because they refelct, obscure, or absorb, the light from  bright stars, b. objects, near around or behind them with variation in surface geometry and illumination. The color appearance of the objects is influenced by many factors, including the geometry of the illumination, the shape of the objects, and the reflectance properties of their materials. Therefore, all of them  do have a natural colour from the elemental composition abundance present in and around them .

Almost all the dark Nebulae rusty or pitch dark ( Absorption Nebulae ) for instance Coalsack (Crux, Musca, Centaurus.) was proven that it is not totally black, but is glowing in a very dim or feeble light.

Wonder any astro gadget vendor from Alaska to N.zealand apart from some Chinese nuts,bolts and some Japanese glass knows much about the true colours of DSOs and naturally ways of mesuring them for a certain period.

Well, im keen on Japanese glass, never seen a better sharper glass to peer into the night sky:happy6:

Best regards and Cs

Rush

 

 

 

Link to comment
Share on other sites
Rush

Rush

Posted
Posted
3 hours ago, sharkmelley said:

I think it is the background in your two examples that differs.  If you made the background more black in both cases then they might look more similar.

I'm not saying I know how to do that though!

Mark

Well i tried Mark, maybe not in the right way, and i kept on missing it,

the back ground and hue changes a bit but couldnt get that colour change.

But you see, look at the Core colour of Ollys Original LRGB, has a brilliant extravagant mached colour than the rest in PI.

Not considering the overall background. Thats what i mean.

Rush.

PS: Have to ask Olly, sure has some hidden tricks, teachers always like hiding something :)

 

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.