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"True" or "False" colour...

Started by ApophisAstros, Jul 05, 2022, 07:16:51

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ApophisAstros

Who knows whats true colour is , i dont think the Hubble pallet is and different optics/processing brings out a miriad of colours as seen on Astrobin.

Which one of these are true colour?
Its all about aesthetics.
Roger
RedCat51,QHYCCD183,Atik460EX,EQ6-R.Tri-Band OSC,BaaderSII1,25" 4.5nm,Ha3.5nm,Oiii3.5nm.

Mac

QuoteWhich one of these are true colour?

The ones where they have attributed the correct RGB to Ha, Oiii & Hb.

The post processing in how they bring out those collours is irellavent as the image is in the correct colour format.

All the others are just incorrect colorizations of the image.

The red blue and green parts of the image are going to be in the correct placing within the spectrum,

So which one of these images is correct.






ApophisAstros

Yes but we can see apples to know the correct colour but who can see a deepsky target with their eyes , observers only see white.

Quote"All the others are just incorrect colorizations of the image."
So everyone else is wrong?
irrelevant
colours
Wrong spelling , wrong colours its all the same. :lol:  :lol:
Roger


RedCat51,QHYCCD183,Atik460EX,EQ6-R.Tri-Band OSC,BaaderSII1,25" 4.5nm,Ha3.5nm,Oiii3.5nm.

Mac

If you take a photo of the apple using a ha filter you will only get the red light from that image.
there is no blue content or green content in that image.

The same applied to the Hb and Oiii for Blue and green.

You are only taking the colours of that image.

If you go and stick them in different position in an RGB image you get all these stupid combinations of RRB RRG BBG BRG ect ect.

They are all incorrect colour images.

The only true colour image is Ha for red, Hb for blue and Oiii for green,
There are other filters that will take different colours within the spectrum, Sii and others for the orange and agua parts, but you need to add those colours back in to the correct position of the spectrum.

Try it for your self as I had to do when doing my degere in astronomy for the photometry part.

Take a terestrial image in Ha, Hb Oiii and combine them in the incorrect position, just as people are still doing. You dont get a true colour image but a false colour.

It might look nice and have pretty colours but its not a true image.

Mac.

ApophisAstros

terminus disputationis
et vanum
Roger
RedCat51,QHYCCD183,Atik460EX,EQ6-R.Tri-Band OSC,BaaderSII1,25" 4.5nm,Ha3.5nm,Oiii3.5nm.

Rick

Even assuming you've put your components in the appropriate parts of the spectrum, there's still the big question about where you draw the line. Some might argue that it's only "true" if it's what the human eye would see, but human vision is complicated. If you want a basic primer, you could do worse than read the annotation notes here. You may have to click the "turn on" link to show the annotation. (There's an extensive rabbit warren full of annotations covering all sorts of subjects on that site. As web comics go, it can be quite informative...)