ep advice

All, I'm looking for a short focal length ep, probably in the 3mm
rangerange for planetary stuff (I currently have the 10mm and 25mm that
shipped with my XT10). My budget won't allow for a Tele Vue -- I'm
trying to keep it around $100.

Does anyone have experience with the Lanthanums, Stratus 68° or
Ultrascopics? They're all in the same price range, and I'm not seeing
much of a difference between them other than the Stratus' 68° FOV.

Lanthanum ep, 3.9mm $99
http://www.telescope.com/shopping/pr...emID=276&itemT
ype=PRODUCT&iMainCat=6&iSubCat=36&iProductID=276

Stratus 68° ep, 3.5mm $119
http://www.telescope.com/shopping/pr...emID=73598&ite
mType=PRODUCT&iMainCat=6&iSubCat=36&iProductID=735 98

Ultrascopic ep, 3.8mm $99
http://www.telescope.com/shopping/pr...emID=242&itemT
ype=PRODUCT&iMainCat=6&iSubCat=36&iProductID=242

tia...

--
Jay Swartzfeger
Scottsdale, AZ

Jay Swartzfeger wrote:
All, I'm looking for a short focal length ep, probably in the 3mm
rangerange for planetary stuff (I currently have the 10mm and 25mm that
shipped with my XT10). My budget won't allow for a Tele Vue -- I'm
trying to keep it around $100.

Have you looked through UO Orthos? They are true Ortho design,
which means they have a slightly smaller FOV, but really excel
for planetary observations. You can find them at
universityoptics.com

Clear Skies

Chuck Taylor
Do you observe the moon? If so, try
http://groups.yahoo.com/group/lunar-observing/

If you enjoy optics, try
http://groups.yahoo.com/group/ATM_Optics_Software/
*********************************************

The Stratus is the best wide field eyepiece in that price range. And,
with a dob, you want wide field. What you don't want is 3.5mm. 342x
is way more magnification than conditions usually permit. I'd get the
5mm or 8mm and add a barlow when conditions permit. The ultrascopics
and Lanthanums are real nice, but it's a lot harder to track with the
narrow field of view. I have an XT8 and use a Meade 6.7mm UWA for
planets. Very nice.

If you don't wear glasses, the Meade Series 5000 Super Plossl's might
be an option. They have 60 degree AFOV, but short eye relief like most
other short FL Plossl's.

Greg

In article .com,
wrote:

The Stratus is the best wide field eyepiece in that price range. And,
with a dob, you want wide field. What you don't want is 3.5mm. 342x
is way more magnification than conditions usually permit. I'd get the
5mm or 8mm and add a barlow when conditions permit. The ultrascopics
and Lanthanums are real nice, but it's a lot harder to track with the
narrow field of view. I have an XT8 and use a Meade 6.7mm UWA for
planets. Very nice.

Greg, thanks for the reply. Pardon my ignorance, but I'm new to the
hobby and not sure about some of the terms/concepts you're using:

1) Why are widefields preferable with a dob? Is it because of the drift
and the constant manual readjustment of the scope? (is this 'tracking'?)

2) I have dark skies and generally excellent seeing/conditions where I
live. Is that 342x out of line considering my typical session?

Chuck had mentioned a University Optics ep, and they have a 4mm for $59
which is mighty tempting, but I know nothing of their
reputation/quality, and a 47° fov.

--
Jay Swartzfeger
Scottsdale, AZ

Go with 7mm UO Ortho---You can always use a 2x if you can ever get up to
that much Power...

Doink
"Jay Swartzfeger" wrote in message
...
In article .com,
wrote:

The Stratus is the best wide field eyepiece in that price range. And,
with a dob, you want wide field. What you don't want is 3.5mm. 342x
is way more magnification than conditions usually permit. I'd get the
5mm or 8mm and add a barlow when conditions permit. The ultrascopics
and Lanthanums are real nice, but it's a lot harder to track with the
narrow field of view. I have an XT8 and use a Meade 6.7mm UWA for
planets. Very nice.

Greg, thanks for the reply. Pardon my ignorance, but I'm new to the
hobby and not sure about some of the terms/concepts you're using:

1) Why are widefields preferable with a dob? Is it because of the drift
and the constant manual readjustment of the scope? (is this 'tracking'?)

2) I have dark skies and generally excellent seeing/conditions where I
live. Is that 342x out of line considering my typical session?

Chuck had mentioned a University Optics ep, and they have a 4mm for $59
which is mighty tempting, but I know nothing of their
reputation/quality, and a 47° fov.

--
Jay Swartzfeger
Scottsdale, AZ

1) Why are widefields preferable with a dob? Is it because of the drift
and the constant manual readjustment of the scope? (is this 'tracking'?)

Yes.

2) I have dark skies and generally excellent seeing/conditions where I
live. Is that 342x out of line considering my typical session?

Magnification depends on how stable the air and is little
affected by how dark the sky is. You can see predictions for
both at http://cleardarksky.com/csk/

Chuck had mentioned a University Optics ep, and they have a 4mm for $59
which is mighty tempting, but I know nothing of their
reputation/quality, and a 47° fov.

Orthos have a smaller FOV, but provide the best view per
dollar for planetary and lunar viewing. The drawbacks are
small eye relief and smaller FOV.

What I'd really recommend is going to
http://skyandtelescope.com/resources/organizations/ and
finding your local astro club. Take your scope to a public
night and set up in the middle. Talk to those around you and
ask their advise. They will quickly pull out a number of
eyepieces (astronomers love to show off) and you can view
through them with your scope and see for yourself.

I suspect you will end up buying something longer than 4- mm.

Clear Skies

Chuck Taylor
Do you observe the moon? If so, try
http://groups.yahoo.com/group/lunar-observing/

If you enjoy optics, try
http://groups.yahoo.com/group/ATM_Optics_Software/
*********************************************

Jay Swartzfeger wrote in news:swartzfeger-
:

In article .com,
wrote:

The Stratus is the best wide field eyepiece in that price range. And,
with a dob, you want wide field. What you don't want is 3.5mm. 342x
is way more magnification than conditions usually permit. I'd get the
5mm or 8mm and add a barlow when conditions permit. The ultrascopics
and Lanthanums are real nice, but it's a lot harder to track with the
narrow field of view. I have an XT8 and use a Meade 6.7mm UWA for
planets. Very nice.

Greg, thanks for the reply. Pardon my ignorance, but I'm new to the
hobby and not sure about some of the terms/concepts you're using:

1) Why are widefields preferable with a dob? Is it because of the drift
and the constant manual readjustment of the scope? (is this 'tracking'?)

Yes. If your scope moves smoothly it may not be a real problem though.


2) I have dark skies and generally excellent seeing/conditions where I
live. Is that 342x out of line considering my typical session?

The only way to know is to try it out. Some folks claim they occaisionly
get conditions where they use mags up to 1000X. For an eight inch scope
anything over 400X is most likely just going to dim the view. If the seeing
is good enough for 400X then count yourself lucky. Remember to make sure
the scope itself is thermally stable and well collimated otherwise the
seeing conditions will not help you.

Klazmon.





Chuck had mentioned a University Optics ep, and they have a 4mm for $59
which is mighty tempting, but I know nothing of their
reputation/quality, and a 47° fov.

Hi Jay, yes, what the others are saying, is that with something like a
UO Ortho, the apparent field of view is quite narrow. You'd have to
nudge the scope every few seconds to keep up with the object.

And I also agree too, 3mm is an eyepiece that will only see use on the
best of nights. On mostly all others, you will find this eyepiece
utterly useless. It's not dark skies that are needed to use these
insane high powers, it is steady seeing conditions.

Something in the 6mm-7mm would be a better choice for a high power
"usable" eyepiece.
Perhaps also in time, a decent 1-1/4" Barlow would be a good thing to
have. Mark

I totally agree with Mark anf Gregg.

Jim M.


"Mark D" wrote in message
...
Hi Jay, yes, what the others are saying, is that with something like a
UO Ortho, the apparent field of view is quite narrow. You'd have to
nudge the scope every few seconds to keep up with the object.

And I also agree too, 3mm is an eyepiece that will only see use on the
best of nights. On mostly all others, you will find this eyepiece
utterly useless. It's not dark skies that are needed to use these
insane high powers, it is steady seeing conditions.

Something in the 6mm-7mm would be a better choice for a high power
"usable" eyepiece.
Perhaps also in time, a decent 1-1/4" Barlow would be a good thing to
have. Mark

Jay Swartzfeger wrote:
All, I'm looking for a short focal length ep, probably in the 3mm
rangerange for planetary stuff (I currently have the 10mm and 25mm that
shipped with my XT10). My budget won't allow for a Tele Vue -- I'm
trying to keep it around $100.

Does anyone have experience with the Lanthanums, Stratus 68° or
Ultrascopics? They're all in the same price range, and I'm not seeing
much of a difference between them other than the Stratus' 68° FOV.

Lanthanum ep, 3.9mm $99
http://www.telescope.com/shopping/pr...emID=276&itemT
ype=PRODUCT&iMainCat=6&iSubCat=36&iProductID=276

Stratus 68° ep, 3.5mm $119
http://www.telescope.com/shopping/pr...emID=73598&ite
mType=PRODUCT&iMainCat=6&iSubCat=36&iProductID=735 98

Ultrascopic ep, 3.8mm $99
http://www.telescope.com/shopping/pr...emID=242&itemT
ype=PRODUCT&iMainCat=6&iSubCat=36&iProductID=242

tia...

--
Jay Swartzfeger
Scottsdale, AZ

I would probably buy a good 3x Barlow first along with perhaps one
other Plossl and learn which magnifications work best for different
objects under a variety of conditions. Only then would I start
upgrading to more expensive and specialized eyepieces.

When tracking a planet, you still want to keep it at or very near the
center of the field, so wide-field eyepieces aren't necessarily
helpful. Wide-field eyepieces are good for finding and viewing deep
sky objects, however.