where is the red stuff?

I am new in Astronomy. I have recently purchased a newton 8" telescope
and have spotted some of the Messier objects and yesterday night for
example got to see M42 with a magnification of 200x. I saw everything
that is in the usual photos except the red color that we usually see in
pictures even of amateurs.

Can someone tell me what's type of telescope you need to see the red
color that makes a real plus.

Thanks

Well, I'm afraid that you will see very little red coloration in M42.
The human eye is very insensitive to red light at the low light levels
present in many deep-sky objects, so the brilliant reds you see in
photographs are usually not visible. In some fairly large apertures
(usually above 10 inches) some very faint hints of reddish coloration
may be seen in M42, but they are pastels. The best powers to use on M42
are those between about 40x and 150x, as they allow you to see much of
the fainter outer detail (especially with narrow-band nebula filters).
The most color you will usually see in nebulae is a sort of bluish-green
hue in the brighter parts, as most of the outer sections will be fairly
colorless. Clear skies to you.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

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"pascal" wrote in message
oups.com...
I am new in Astronomy. I have recently purchased a newton 8" telescope
and have spotted some of the Messier objects and yesterday night for
example got to see M42 with a magnification of 200x. I saw everything
that is in the usual photos except the red color that we usually see in
pictures even of amateurs.

Can someone tell me what's type of telescope you need to see the red
color that makes a real plus.

Thanks
Basically, you don't....
The key unfortunately, is your eyes. At low intensity, your visual system,
'switches' to a black and white mode. You only see colour, when things are
really bright. Now an 8" scope, can allow you to see colour, but only in a
very few of the brightest objects (The Orion Nebula for example). For
anything much dimmer, you are not going to see that colour.
Look at:
http://www.astropix.com/HTML/I_ASTROP/I14/I14.HTM

Now the strong red detail you are talking about, is probably done by
imaging through an 'Ha' filter. This passes one key wavelength emitted by
hydrogen gas, and has the lovely advantage (from an imaging point of
view), of excluding 99% of the light from street lights etc.. This gas
emission, is red, but using such a filter visually, will dim the objects
so much, that except for the very brightest, you are not going to see
anything. M42, will show this red visually (one of the few things that
will), but without the Ha filter, the colour is 'lost' in the light of
other colours, and even with the filter,visually, only the brightest
'core' of the nebula will be seen. The wisps outside the nebula, are
probably perhaps 1000 times dimmer than you could visually see...
So, you are not going to see colours like this, visually, with ay
reasonable sized scope.

Best Wishes

Thanks all for these infos. I guess there is nothing more to expect
from a LX200 8" then (which I was planning to buy)
Pascal.

"pascal" wrote in message
oups.com...
Thanks all for these infos. I guess there is nothing more to expect
from a LX200 8" then (which I was planning to buy)
Pascal.

You can alway try your hand at astrophotography.

George

On 23 Jan 2006 01:13:20 -0800, "pascal"
wrote:

Can someone tell me what's type of telescope you need to see the red
color that makes a real plus.

In addition to what others have said, keep in mind that a telescope
makes extended objects larger, but it doesn't make them brighter. When
you look at M42 with your naked eye, do you see color? (The nebula is
easy to see, with the bright core more than half the size of the Moon.)
If an object is below the threshold of color perception without a
telescope, it will still be so with a telescope- regardless of the size
of the aperture. Indeed, you could travel towards Orion until the nebula
filled the sky, and it would still only look like a gray or greenish
cloud.

If you want color, you need to use a sensor other than the eye- film or
silicon.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

pascal wrote:
Thanks all for these infos. I guess there is nothing more to expect
from a LX200 8" then (which I was planning to buy)



Not unless you do astrophotography.

On 2006-01-23, pascal wrote:
I am new in Astronomy. I have recently purchased a newton 8" telescope
and have spotted some of the Messier objects and yesterday night for
example got to see M42 with a magnification of 200x. I saw everything
that is in the usual photos except the red color that we usually see in
pictures even of amateurs.

Can someone tell me what's type of telescope you need to see the red
color that makes a real plus.

You get the red color in photographs because film and CCDs are more
sensitive to color than your eyes. You don't see red through the
eyepiece because your eyes are not as sensitive to color in dim light.
"At night all cats are gray." Some people say they see some red in the
Orion Nebula. I don't. The stars vary a little in tint, but the nebula
looks at most very slightly green.

--
The night is just the shadow of the Earth.

"Chris L Peterson" wrote in message
...
On 23 Jan 2006 01:13:20 -0800, "pascal"
wrote:

Can someone tell me what's type of telescope you need to see the red
color that makes a real plus.

In addition to what others have said, keep in mind that a telescope
makes extended objects larger, but it doesn't make them brighter. When
you look at M42 with your naked eye, do you see color? (The nebula is
easy to see, with the bright core more than half the size of the Moon.)
If an object is below the threshold of color perception without a
telescope, it will still be so with a telescope- regardless of the size
of the aperture. Indeed, you could travel towards Orion until the nebula
filled the sky, and it would still only look like a gray or greenish
cloud.

If you want color, you need to use a sensor other than the eye- film or
silicon.
M42, has quite visible colour in many larger scopes (and without chromatic
aberration being involved!), especially for younger observers. Greenish,
some yellows, and a little red. A telescope cannot make an object brighter
than it actually 'is', but it can increase the perceived brightness by the
eye. This is because the processing inside the eye, to some small extent
behaves like 'binning' on a CCD, and as more sensors are triggered (which
the telescope magnification brings), dimmer colours can be seen. Things
that are 'on the edge', giving slight triggers on a few cells, but with
the numbers too few, to be seen as 'colour', can when viewed through a
large enough scope, show quite visible hues. However these colours are
very faint indeed.
There was a test some years ago, which illustrated this, with a spot
illuminated at a constant intensity, with a coloured light, and masks
increasing the size of the area seen by the eye. At small areas, no colour
was seen, but as more of the retina was covered, colour became detectable.
Nothing like the pictures though!.
M42, falls right on the 'edge', of the brightness levels needed to trigger
colour vision. There is a good chance, that most people here are too old,
to see any colour there at all (your ability to detect colour, declines
with age, as do most other things in the body, and there is a significant
variation in colour sensitivity between individuals). It requires a well
dark adapted eye, but some colour can be seen by many observers in larger
scopes.

Best Wishes

On Mon, 23 Jan 2006 15:56:02 GMT, "Roger Hamlett"
wrote:

M42, has quite visible colour in many larger scopes (and without chromatic
aberration being involved!), especially for younger observers. Greenish,
some yellows, and a little red. A telescope cannot make an object brighter
than it actually 'is', but it can increase the perceived brightness by the
eye...

I haven't personally noted this, but I know others have. I see a faint
greenish color with M42 whether I view it naked eye, through binoculars,
or through a larger aperture.

Other than M42 and a few strong OIII planetaries, I don't recall ever
seeing astronomical color in anything other than planets and stars.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com