Colour Perception

[barees63]

Hi all,

I've been wondering about colour perception when viewing, I seem to see very little if any colour when viewing object like M42 and Ghost of Jupiter.. When I showed M42 to my brother and my daughter both remarked straight away on the blue-green colour but when I look at it I see shades of gray, similarly when viewing the Ghost of Jupiter last night, I knew it was bluish from looking at photographs but to me there was no really distinct colour yet on looking at some web-pages about it tonight most remarked that it is seen as distinctly blue through a telescope.. do you find people have varying degrees of colour perception at night or is just me?

Bruce

[Robert_T]

Hi Bruce, colour perception of very faint objects is a bit of a combination of physiology (how good your eyes are and the function of the light and colour receptors in your retina - "rods" and "cones" though I can never remember which is which) and practice. Many observers report that the more and longer they observe objects such as M42 the more colour they see, even the pinks as well as the green - not that you'd ever see the same vividness of colour that images bring out.

cheers,

[RAJAH235]

Bruce, The human eye processes the info received immediately, unlike a film or ccd. Therefore to actually 'see colour' we need a fairly large aperture t'scope to gather the avail photons. The cones are the cells that do this. ( cones = colour).
With a larger t'scope, >8", you should be able to see a faint green glow in M42, poss a bit of pink to very faint red. Age becomes a factor as well.
I can see green with just a hint of pink in my 10" dob & @ 60 yrs, I think that's great. Conditions have to be pretty good too. L.

[[1ponders] (Paul)]

Yep, age, genetics, observing skills and sex (yep woman can see colour better than men, lucky ladies) can all play a big part in this. To me the blue planetary is definately very blue and M42 is definately greenish (most of the time and depending on what scope I'm looking through). Yet a friend of mine can only see the blue planetary as greenish and sees faint pink in M42. The bottom line is some eyes cant, some eyes can and much of that depends on conditions.

[jjjnettie (Jeanette)]

Sounds like you need to eat more carrots Bruce. Australian S&T has an article on how to improve your night vision. It might be worth having a look at.

[RAJAH235]

For the lowdown on "all things eyes", why not simply ask your local Optometrist or Optician. Bound to have a store near you. Only too happy to help....Luckily we have one in our club.. L.
ps.carrots ain't gonna cut it..

[barees63]

ps.carrots ain't gonna cut it..

yes, it's weird.. I have seen an optometrist and eye specialist recently (not related to astronomy.. just reading/work I'm a programmer by trade) but apparently there's no problem other than normal aging, I seem to see plenty of detail and I see colors on stars (eg jewel box) and planets just not the nebula colors.. oh well.

[fringe_dweller]

I have always been surprised how little colour people report seeing in m42 on this forum, to me it has always been very, very colourful. In addition to the straight winegum green and blue's i see a lot of magenta/violet.

[ving (David)]

you, oh dewller of the fringe are a very lucky person

I see a very vivid green in my 8" and a somwhat duller green in my 60mm

[fringe_dweller]

hehe thanks David think ill have to donate my eyes to science by the sounds of it? LOL!
Pity about the exponentionally multiplying with age floaties ;( they are getting to be a nuisance!

[ving (David)]

can the floaties be removed?

[fringe_dweller]

Not that I know of mate - I dont even know what causes them but everyone gets them eventually, I believe?
EDIT: they are much worse when my eye's or myself are tired ie. too much online gaming or reading (especially off the puter)

[stinky]

I believe floaties are chains of proteins. Here is an interesting illusion that shows how the cones in the eye work - particularily persistence. Try it out. For some the effect is instant - others need to stare.

http://www.patmedia.net/marklevinson..._illusion.html

[Starkler (Geoff)]

Originally Posted by ving

can the floaties be removed?

I saw on tv once a laser procedure for zapping large floaters where they become a problem for normal day vision. Whether this can be done to the satisfaction of observers I dont know.

[ausastronomer (John Bambury)]

Bruce,

You raise this question at a very opportune time.

Firstly let me say as others have, that everyones eyes are different and perceive low levels of colour differently. In addition perception of colour in diffuse targets is apperture dependant as a larger scope plain and simply allows more photons to strike the cones at a given instant than a small scope.

I spent a bit of time with Andrew Murrell and his 20" scope discussing colour in M42 on Friday Night and with Houghy and Ed Roca (Orion) discussing exactly the same thing around Ed's 18" scope on Saturday night, at IISAC at Lostock.

On the Friday We observed M42 in the 20" at twilight and it was very greenish in colour. Andrew Murrell explained that this effect was very pronounced at twilight and the colour faded significantly as the skies darkened, this is exactly what I saw. Why, I have no idea.

On the Saturday I observed M42 in Ed's 18" scope with Ed and Houghy through a couple of different eyepieces belonging to Houghy. Including a 20mm T5 Nagler, a 24mm Meade S5000 Super Wide and a 34mm Meade S5000 Super Wide (I think it was). I must say both the Meade eyepieces were physically very impressive if bigger is better, they were marginally larger than a house brick and about as heavy . Reasonable performers in Ed's F4.5 scope, not as good as the 20mm Nag T5 which is infinitely more expensive. I was able to detect some pink and blue tinges over various parts of the nebula in all the eyepieces, no green. So here we have it green on Friday and pink and blue on Saturday. Two similar aperture telescopes on consecutive nights under similar conditions and spaced 30 metres apart. GO FIGURE, cause I can't figure it . But it gets better, later that evening I returned to my own 10" dob and got perceptions of green in M42, 2 hours after I got pink and blue in Ed's scope.

CS-John B

[rumples riot]

Bruce, I have to agree, colour is largely dependant upon transparency, your eyes and the scope you are using. In both my SCT's I sometimes see greenish hues and sometimes not. Larger scopes generally show with my eyes more colour. Don't worry, though the view is all that matters, not the colour.

[barees63]

effect was very pronounced at twilight and the colour faded significantly as the skies darkened,

I wonder (having read the AS&T article) if this is due to the "cones" which perceive colour progressivley switching off as it gets darker in favour of the rods which are for night vision and do not perceive colour. the other thing I notice is I seem to have weaker perception of blue at night in particular so that may explain why I can see red/yellow stars and planets with ease but struggle on blues and greens.

I'm not really too worried as I never expected to see colour in nebulous objects anyway.. just a bit miffed when others go on about the wonderful shades of green/pink/magenta they are seeing (********!) :-)

Fringe-dweller, I have increasing floaters in my eye as well, particularly the eye I use for the telescope (dammit!), the optometrist told me most floaters are remnants of blood vessels?

[slice of heaven]

Originally Posted by barees63

just a bit miffed when others go on about the wonderful shades of green/pink/magenta they are seeing

Your not alone

I only get black and white reception also

[barees63]

maybe those other bozos are imagining it? looked at too many Hubble pictures so brain colours it in for them?

[OneOfOne (Trevor)]

Originally Posted by fringe_dweller

hehe thanks David think ill have to donate my eyes to science by the sounds of it? LOL!
Pity about the exponentionally multiplying with age floaties ;( they are getting to be a nuisance!

Damn it, I thought I could see black holes!