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will you ever see colour while observing? noob


leenewtoastro

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I think this must be down to the induvidual and the location more than anything

To see red (e.g. in M42 or IC 418) you will probably need large aperture (16" or more) and a dark sky. Some people have reported seeing red in those objects with smaller aperture but they still needed a dark sky (limiting magnitude 6+), full dark adaptation, and plenty of practice.

very interesting acey, I have observed a tinge of red in one or two nebula, M57 the Ring Nebula and indeed M42, I even did a small observing report on the appearance of M42 stating I had seen some red as well as the green, as I had yet, until this report. read anything similair I thought it must have been me. It has not been the case everytime I observe by any means but I now feel I must have seen it. My skies are around +4.6 limiting mag so no were near the +6 you state and it was with the 925 but I was using Televue ep's, wonder if that lot would be enough to pick out such detail? I will double check this and give a report in due course :)

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I'm honestly sceptical about the possibility of seeing red in M57. But everybody's eyes are different and we perceive things in different ways. In dim light all things become "colourless" because our cones aren't activated, but often we can still "perceive" colour - just try looking at objects in really dim light to test this. I have in the past thought I saw a tinge of red in M42 with an 8-inch, when I was fairly new to deep-sky viewing, and in retrospect I think it was wishful thinking. Or maybe I subsequently convinced myself I shouldn't be able to see it. It's one of those subjective things where in the end it comes down to your own judgment.

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Well it was probably me acey, regarding the ring nebula, I did want to point out another object I definately do see a decent amount of red in and it appears to cover a fair portion of the sky, The Rosette nebula, anyone else want to confirm this?

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I think you must have unusual eyes!

well I hope to have that confirmed pretty soon :(, as I am about to get an astro society going for this area in a few weeks I will be able get a few other opinions on one of two objects, will be interesting to hear what people say. :)

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I'd be happy just to see 2244 let alone make out colour in it :) I thought a filter was necessary to see it ? so would this not remove colour ??

Hi spaceboy, I looked into the rosette nebula last night to try and get any info on what one can observe.

Quote, from Philip's complete guide to Stargazing, page 130, though its location is readily found, all that MOST people can see visually is a small cluster of stars known as NGC 2244.

it does cover a large area of the sky 80'x60' by comparrison the Orion nebula covers 60'x60', details taken from Philip's Atlas of the Universe.

I have yet to use any type of filter for observing dso's although I intend to buy both a UHC and OIII soon.

as I have already stated above I will get a second opinion of this in due course but I believe I have indeed observed it. :(

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Yes. Hours spent on a computer using imaging software to add different layers of colour.

Planets show colour. Some stars also.

I had assumed that when imaging, the long exposures were what allowed the cameras to capture colours.

Are you saying that the cameras only see what we see, but the imagers add colour later using software?

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I had assumed that when imaging, the long exposures were what allowed the cameras to capture colours.

Are you saying that the cameras only see what we see, but the imagers add colour later using software?

No no. The camera picks up colour and detail that we dont really see. The people who do imaging and processing on a computer enhance what the camera sees.

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Think of it this way: what colours are "really there"? All depends on the electromagnetic wavelengths being emitted by the object, the sensitivity of the detector (eye or camera) to those wavelengths at particular intensities, and the processing (by computer or brain) applied to the output from those detectors.

But we can say this: if you flew really close to the Rosette nebula you would still probably not see colour in it. Instead you would see a very large, faint glow, comparable to the Milky Way in brightness - easily drowned out by any artificial lights left on inside your spaceship.

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No no. The camera picks up colour and detail that we dont really see. The people who do imaging and processing on a computer enhance what the camera sees.

I guess this is the bit that I'm struggling to understand. Does the camera/CCD actually pick up colours that the eye cannot see, and then software enhances those colours in to something we can see? I thought a camera could only see what we see.

I could understand some kind of special electronic device picking up different wavelengths then software converting that in to a colour that we know corresponds to that wavelength, but I just can't get my head around a camera being able to see things that the eye can't.

I don't want to upset the imaging guys by questioning what they do, but it seems that they are just applying colours to something that is actually monochrome.

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Think of it this way: what colours are "really there"? All depends on the electromagnetic wavelengths being emitted by the object, the sensitivity of the detector (eye or camera) to those wavelengths at particular intensities, and the processing (by computer or brain) applied to the output from those detectors.

But we can say this: if you flew really close to the Rosette nebula you would still probably not see colour in it. Instead you would see a very large, faint glow, comparable to the Milky Way in brightness - easily drowned out by any artificial lights left on inside your spaceship.

So how do we know what colours are actually there?

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I'm able to see the rosette as a faint gray cloud with no color hints and barely any structure. The OIII helps making it more noticeable.
I've seen the Rosette with an 8-inch at a dark site; a UHC filter gave a better view. No colour was apparent to me in either case: I see all faint DSOs as grey.

So it is possible but only at a dark site ? How dark ? as for me 5-5.5 magnatude stars are a 40 min drive and 90 mins to 6 mag.

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5.5 should be enough for a 8". That's my usual limiting mag and I seen it. On excellent transparency I get over 6.

It's a very large object and you need very low power widefield to notice the subtle difference in shade from dark background. To me it's about as hard as the North America nebula.

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So how do we know what colours are actually there?

Some images you see show red from near infrared light, our eyes have trouble picking and usually ignore if the object emits brighter light, in other wavelenghts. Then you also have the problem with the cones and rodes already explained.

Other images are captured in mono chrom. This capture separate wave lengths, emitted by different atoms at a time. Later on, they are stacked in a PC using a different, artificial, color to represent each atom. They are meant to study the composition of an object. Here's a well know example of false color:

APOD: 2007 February 18 - M16: Pillars of Creation

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I checked on Stellarium to see if there was something I may be missing here, its seems pretty clear I am not looking at the rosette, on stellarium around that region just above Monoceros there's an area showing a lot of red which includes the rosette itself as well as other ngc's, I tried to inlude the whole area on the search option but I could not get any answer as to what its called, am I seeing this whole region as it appears on stellarium? if so does anyone know what it is?

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