Re: double cluster

On 22 Mar 2007 10:42:08 -0700, "olli" <olivier.vdf@xxxxxxxxxx> wrote:

I have the 35 mm panoptic 2" eyepiece and i want to buy second hand
the Meade
LX200 gps 10" scope!!
From my opinion with the 35mm panoptic 2" i can't have the
doublecluster in one field of view or am i wrong.?

If the Panoptic makes use of the full inside diameter of the 2-inch
O.D. barrel for its field stop (I don't have that eyepiece, so I don't
know) and if the 10-inch scope has a 2500mm focal length, then you
should be able to get a true field of view approximately equal to 1.0
degrees.

The double cluster is about 1.0 degrees long along its longest axis.
So it looks like you *might* be able to just squeeze both clusters
into a single field; but it will be *close*. The double cluster would
look better with a telescope that has a significantly shorter focal
length (significantly shorter than 2500mm).

Perhaps someone with first-hand experience with that telescope and
eyepiece could clarify. My numbers are based on a bit of math along
with my experience with a different 2-inch eyepiece and a different
telescope (I can get a true field of 1.73 degrees using a telescope
that has a focal length of 1500mm.)

What could be the best combination of eyepieces to see the double
cluster in one field of view ?
Maybe the 55mm plossl 2" from televue? or the new TMB Paragon 40 mm
(69°)

The eyepiece with the largest field stop would provide the widest true
field. I suspect that none of the other eyepieces would be noticeably
better than your 35mm Panoptic; but I'm not 100% certain!
--
Bill
Celestial Journeys
http://cejour.blogspot.com
.

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