Good Place to buy lenses

I have a Orion XT6. It came with a 25mm and 10mm lense, I can see
Saturn's rings with this, but I want to see it more clearly, hopefully
some colours in the rings. Is that at all possible with a 6inch
telescope? I guess I need a more powerful lense. Are there any reliable
websites where I can buy say 5mm lense?

tulika wrote:

I have a Orion XT6. It came with a 25mm and 10mm lense, I can see
Saturn's rings with this, but I want to see it more clearly, hopefully
some colours in the rings. Is that at all possible with a 6inch
telescope? I guess I need a more powerful lense. Are there any reliable
websites where I can buy say 5mm lense?


They are called Eyepieces. Your quality of viewing may be limited to
the amount of atmosphere and water vapor you are trying to view Saturn
through. I would think with a 6 inch you should be able to see
differences in Saturns rings with your 10mm, though that may be a bit
higher magnification than you need. I'd recommend somthing around 12-15
mm. You may need filters, too. I'm still a bit new to the idea of
filters, myself, but I think you may check back threads (through Google
Groups) to see what pieces are well recommended and, importantly, which
to avoid.

tulika wrote:
I have a Orion XT6. It came with a 25mm and 10mm lense, I can see
Saturn's rings with this, but I want to see it more clearly, hopefully
some colours in the rings. Is that at all possible with a 6inch
telescope? I guess I need a more powerful lense. Are there any reliable
websites where I can buy say 5mm lense?



Your best buy might be a 2x barlow, which will double the magnification
of each eyepiece you own. So you would then have 25, 12.5, 10 and 5 in
effect.

The Orion Shorty Barlow Plus is well regarded and on sale now.

The focal length of the XT6 is 1200 mm, I think. That means the 10 mm
EP you have is giving you 120x; you want a bit more, but not too much
more. 5 mm would double that to 240x, which could be too much,
depending on the conditions of your skies.

I'd consider the Barlow above plus an 8 and/or 6 mm EP for 150x and 200x
respectively. But, given the EPs you now have, I'd get an 8 mm and 6 mm
EP first, if you want to get better views of Saturn.

Likely you can find reasonable EPs at Orion. I like University Optics
orthos for planetary views at a reasonable price ... but I'm not sure
how they would work in your scope. So perhaps a dob user will advise.

Phil

Likely you can find reasonable EPs at Orion. I like University Optics
orthos for planetary views at a reasonable price ... but I'm not sure how
they would work in your scope. So perhaps a dob user will advise.

Othos provide great views but have, by todays standards, a limited field of
view and poor eye relief. The fov issue is especially undesireable in an
undriven dob, as targets exit the field all the more quickly when the field
is small. I would go with the good quality barlow (e.g. Orion Shorty Plus).
However, be aware that higher powers require 1) good optics, 2)
well-collimated optics, 3) optics acclimated to the ambient temperature, and
4) good seeing. If these pre-conditions are not met then no eyepiece will
provide good high-power views.

Finally, your best bet is to seek out your local astro club. They will
share their expertise and equipment, and will help you to make good
decisions. A 6" f/8 dob can provide great views of the planets, but you
need to learn how to achieve them.

Dennis

Thanks everyone, I will checkout a 2x barlow. I am in the north-west
area and light pollution is just too much, but we get so few clear
nights here that I run out to nearest possible park whenever any any
stars are visible.

I make sure that the telescope is left outside for about 30min to get
it acclimated to temperature.
what does 2) well-collimated optics, mean ?

tulika wrote:
Thanks everyone, I will checkout a 2x barlow. I am in the north-west
area and light pollution is just too much, but we get so few clear
nights here that I run out to nearest possible park whenever any any
stars are visible.

I make sure that the telescope is left outside for about 30min to get
it acclimated to temperature.
what does 2) well-collimated optics, mean ?



Collimation relates to the alignment of the primary mirror and secondary
mirror. Your manual should tell you about it and how to do it. This
site likely has more on the subject than you will ever want to know

http://www.catseyecollimation.com/mccluney.html

This might be easier to read:

http://web.telia.com/~u41105032/kolli/kolli.html

Anyway, do look for info in manual because the details will depend on
your scope's design details.

Phil

tulika wrote:

I have a Orion XT6. It came with a 25mm and 10mm lense, I can see
Saturn's rings with this, but I want to see it more clearly, hopefully
some colours in the rings. Is that at all possible with a 6inch
telescope?

It's possible that you have unrealistic expectations. Saturn's rings
are
exceedingly beautiful, but I would *not* describe them as colored.
NASA has published some false-color photos of the rings that have
given people very false impressions of what they ought to look like.
I would describe them as white -- in contrast to the slightly yellow
tint of the planet itself. But *all* colors on the planets are very
subtle,
basically shadings of white or very faint pastels.

- Tony Flanders

On Mon, 13 Feb 2006 10:12:46 -0600, tulika
wrote:

I have a Orion XT6. It came with a 25mm and 10mm lense, I can see
Saturn's rings with this, but I want to see it more clearly, hopefully
some colours in the rings. Is that at all possible with a 6inch
telescope? I guess I need a more powerful lense. Are there any reliable
websites where I can buy say 5mm lense?


For high power planetary viewing, you may wish to invest in an
Orthoscopic eyepiece of 6mm - 7.5mm focal length.

To get the best views with your scope, especially for high
powers, the telescope optics must be properly collimated.

You may wish to do web searches on both items.

Cheers,
larry g.

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Saturn's rings
are
exceedingly beautiful, but I would *not* describe them as colored.
NASA has published some false-color photos of the rings that have
given people very false impressions of what they ought to look like.
I would describe them as white -- in contrast to the slightly yellow
tint of the planet itself. But *all* colors on the planets are very
subtle,
basically shadings of white or very faint pastels.


They show a slight cool grey shade in both my 6 and 9.6 inch reflectors
which gives the illusion of a touch of violet next to the colors of the
planet.
And the SEB appears distinctly light bown-ochre at the eyepiece for me.

Most ccd Saturn images taken by amateurs also show these colors, albeit

more pronounced.

The brown seen in Jupiter's NEB is sometimes anything but subtle.
Yes, most colors seen on planets are subtle, sometimes enhanced
by opposites, but NOT all.

Dan C.

decaf wrote:

The brown seen in Jupiter's NEB is sometimes anything but subtle.
Yes, most colors seen on planets are subtle, sometimes enhanced
by opposites, but NOT all.

Well, I certainly won't argue the point. I've seen some very striking
browns -- and blues -- on Jupiter. But they're not brown like tree bark
nor blue like the daytime sky. Not even close.

Let's put it this way. If you expect the planets to be monochrome,
then you'll be pleasantly surprised when you see colors on them.
But if you expect them to have vivid, saturated colors, then you're
setting yourself up for disappointment.

- Tony Flanders