Meade refractor question

My first telescope, which I still have is a Meade model # 289S 60 X 900mm
refractor. I bought it second or third hand??? My question is, why does
Saturn look yellow/orange with this scope? I have used the .965" optics and
with a new star diagonal I have tried several different 1 1/2" ones as well.
Saturn doesn't look this color in any of my reflectors. I don't use the 60mm
much any more but last night I took it outside for a quick peek and while
Jupiter was a nice white disk at 90x (about all this scope will support
without going to fuzz) Saturn was orange.
Thanks
Tom Wales

On Sat, 10 Apr 2004 01:10:46 GMT, "Tom Wales"
wrote:

My first telescope, which I still have is a Meade model # 289S 60 X 900mm
refractor. I bought it second or third hand??? My question is, why does
Saturn look yellow/orange with this scope? I have used the .965" optics and
with a new star diagonal I have tried several different 1 1/2" ones as well.
Saturn doesn't look this color in any of my reflectors. I don't use the 60mm
much any more but last night I took it outside for a quick peek and while
Jupiter was a nice white disk at 90x (about all this scope will support
without going to fuzz) Saturn was orange.

Because typical achromats are corrected to focus best in yellow-
green light, leaving red and blue equally out of focus. So if you have

an image that is naturally leaning towards yellow- ochre, as Saturn
does, it will be more intensely seen as yellowish in such an achromat
than such a perfectly color corrected instrument as a newtonian or
cassegrainian. Since the natural view Jupiter is much less yellowish,
it appears closer to a cream tint than Saturn when using an achromat.
I value achromats for several reasons, but natural color isn't one of
them:-)

DC

On Sat, 10 Apr 2004 01:10:46 GMT, "Tom Wales"
wrote:

My first telescope, which I still have is a Meade model # 289S 60 X 900mm
refractor. I bought it second or third hand??? My question is, why does
Saturn look yellow/orange with this scope? I have used the .965" optics and
with a new star diagonal I have tried several different 1 1/2" ones as well.
Saturn doesn't look this color in any of my reflectors. I don't use the 60mm
much any more but last night I took it outside for a quick peek and while
Jupiter was a nice white disk at 90x (about all this scope will support
without going to fuzz) Saturn was orange.

Because typical achromats are corrected to focus best in yellow-
green light, leaving red and blue equally out of focus. So if you have

an image that is naturally leaning towards yellow- ochre, as Saturn
does, it will be more intensely seen as yellowish in such an achromat
than such a perfectly color corrected instrument as a newtonian or
cassegrainian. Since the natural view Jupiter is much less yellowish,
it appears closer to a cream tint than Saturn when using an achromat.
I value achromats for several reasons, but natural color isn't one of
them:-)

DC

That is the color of Saturn and larger scopes will tend to overload the eye
with brightness over the color and that may be why you are not seeing the
color of the planet. The smaller scope isn't overloading the eye as much so
you tend to see it in the color that it is.

--
Bob May
Losing weight is easy! If you ever want to lose weight, eat and drink less.
Works every time it is tried!

That is the color of Saturn and larger scopes will tend to overload the eye
with brightness over the color and that may be why you are not seeing the
color of the planet. The smaller scope isn't overloading the eye as much so
you tend to see it in the color that it is.

--
Bob May
Losing weight is easy! If you ever want to lose weight, eat and drink less.
Works every time it is tried!