TELESCOPE on a cruise?

bioeve wrote:
I want to take my telescope on my Alaskan in Aug 2010. I know the boat
travels in protected water(calm waters) and the sun doesn't set until
10:30pm. The boat will only be docked one day after sunset. Do you think
I will see anything fun and interesting with those conditions?

IMO, probably not, if for no other particular reason than that at high
lattitudes, the duration of summertime twilight is extremely long and
it may not get as dark as you want. As such, you probably will want
to look up the times for the end of astronomical dusk ... not merely
"sunset" ... for the dates of your trip.

For example, as per www.timeanddate.com and using Anchorage, AK:

For 1-18 August 2010, there is no astronomical dusk (sunset/sunrise)
at all: the darkest it gets is to astronomical twilight.
Furthermore, for 1-5 Aug, it doesn't even make it to as dark as
astronomical twilight: only nautical twilight.

Picking 10 Aug 10 as an example,
sunset is at 10:12pm,
then you have ~1 hour of civil twilight (until 11:10pm),
then you have ~1.75 hours nautical twilight (until 12:55am),
then you have ~2.5 hours of astronomical twilight (until 3:23am)

...but this isn't "darker" to astronomical dusk because dawn is
approaching and its now getting brighter, so you're back "up" to
nautical twilight. Nautical twilight passes to civil twilight at
5:01am, and civil twilight passes to sunrise at 5:58am.

Looking forward to the first day in August 2010 in which there is a
full astronomical dusk, this would be the night of 25 August, and it
is similarly drawn out: while sunset is at 9:27pm, you don't hit the
end of astronomical twilight until over 5 hours later, at 2:41am.


I have not found much information on this topic, so I am thinking
it doesn't happen much....

Consider doing some research on what is generally recommended as the
maximum focal length for still photography while onboard a ship.

FWIW, the last time that I did this, the general recommendations were
to consider no more than a 300mm lens. Since a telescope is typically
a greater magnification than this, you're likely to have some degree
of issues with the non-stable "floating" platform, particularly when
not docked.


-hh

The sole advantage of a telescope is magnification, but a ship imposes
practical limits. My home telescope (a 6" refractor) is on a massive
tripod and is satisfactory only on concrete. I took a 30x spotting scope
(erect image) on a cruise once, but the slightest ship motion made it
unusable.

Binoculars are more portable, provide 3D (both eyes), are easier to use,
and work better in low light than a typical telescope. For the last 100
years, the best all-around glasses have been between 7 and 10 power. In
binocular specification such as 7X50, the bigger the first number the
higher the magnification - and the shakier the image. 10 is the limit
without a tripod. The second number in 7x50 tells you the diameter of
the objective lens, which determines light-gathering ability - the
bigger the number, the better in low light. At noon, even 8X30 is
usually fine.

It's fun and interesting to have glasses on a cruise that spends time
near shore - Alaska is a perfect example, and there's a lot to see. And
when you're in port, get a high vantage point and look at the city -
it's often fascinating. Of course, many ships have observation resources
including mounted telescopes.

Ike


bioeve wrote:
I want to take my telescope on my Alaskan in Aug 2010. I know the boat
travels in protected water(calm waters) and the sun doesn't set until
10:30pm. The boat will only be docked one day after sunset. Do you think
I will see anything fun and interesting with those conditions?

I have not found much information on this topic, so I am thinking it
doesn't happen much....

"Ike" wrote in message
...
The sole advantage of a telescope is magnification, but a ship imposes
practical limits. ... Binoculars are more portable, provide 3D (both
eyes), are easier to use, and work better in low light than a typical
telescope. ...
It's fun and interesting to have glasses on a cruise that spends time near
shore - Alaska is a perfect example, and there's a lot to see. And when
you're in port, get a high vantage point and look at the city - it's often
fascinating. Of course, many ships have observation resources including
mounted telescopes.

bioeve wrote:
I want to take my telescope on my Alaskan in Aug 2010. I know the boat
travels in protected water(calm waters) and the sun doesn't set until
10:30pm. The boat will only be docked one day after sunset. Do you think
I will see anything fun and interesting with those conditions?
The boat??
We are absolutely taking binoculars next time. Last November as we cruised
by Gibraltar, maybe two miles away, we could barely make it out due to haze.
Even the telescopes on the ship (Oceania Insignia) didn't make it clear.
However, a couple also looking at the rock handed us their binoculars.
Looking through them made the rock almost crystal clear. I'm not sure how,
but I'm a believer.
Paul Johnson

One more point...

I'm working on a (personal) project that will transfer a telescope's
image (or one side of a binocular's image) onto my computer screen in
high resolution, in real time. It's pretty simple, and uses the CMOS
imaging device from a scrapped digital camera. It will be easier to look
at, and I can also add digital magnification. Should be ready for our
next cruise, in February.

Ike

Paul Johnson wrote:
"Ike" wrote in message
...
The sole advantage of a telescope is magnification, but a ship imposes
practical limits. ... Binoculars are more portable, provide 3D (both
eyes), are easier to use, and work better in low light than a typical
telescope. ...
It's fun and interesting to have glasses on a cruise that spends time near
shore - Alaska is a perfect example, and there's a lot to see. And when
you're in port, get a high vantage point and look at the city - it's often
fascinating. Of course, many ships have observation resources including
mounted telescopes.

bioeve wrote:
I want to take my telescope on my Alaskan in Aug 2010. I know the boat
travels in protected water(calm waters) and the sun doesn't set until
10:30pm. The boat will only be docked one day after sunset. Do you think
I will see anything fun and interesting with those conditions?
The boat??
We are absolutely taking binoculars next time. Last November as we cruised
by Gibraltar, maybe two miles away, we could barely make it out due to haze.
Even the telescopes on the ship (Oceania Insignia) didn't make it clear.
However, a couple also looking at the rock handed us their binoculars.
Looking through them made the rock almost crystal clear. I'm not sure how,
but I'm a believer.
Paul Johnson


If your budget will allow it, there are some superb stabilized
binoculars available that take all the jumping out of the views.
Definitely not inexpensive but very, very nice. Look up some ratings and
try out before you purchase - this is definitely an item you need to try
before you buy.
Cheers,
John in LALALand (On the Left Coast)

On Wed, 21 Oct 2009 05:46:28 -0500, bioeve
wrote:


I want to take my telescope on my Alaskan in Aug 2010. I know the boat
travels in protected water(calm waters) and the sun doesn't set until
10:30pm. The boat will only be docked one day after sunset. Do you think
I will see anything fun and interesting with those conditions?

I have not found much information on this topic, so I am thinking it
doesn't happen much....

If you're planning on stargazing, it's hard to find dark outdoor
places on modern ships. There are lights, or the reflection of
lights, everywhere.

Jack Hamilton wrote:
On Wed, 21 Oct 2009 05:46:28 -0500, bioeve
wrote:

I want to take my telescope on my Alaskan in Aug 2010. I know the boat
travels in protected water(calm waters) and the sun doesn't set until
10:30pm. The boat will only be docked one day after sunset. Do you think
I will see anything fun and interesting with those conditions?

I have not found much information on this topic, so I am thinking it
doesn't happen much....

If you're planning on stargazing, it's hard to find dark outdoor
places on modern ships. There are lights, or the reflection of
lights, everywhere.



Stargazing on a cruise ship? I don't think so, due to the light and also
due to the motion.

On the other hand, looking into passing cruise ships might be interesting...

"bioeve" wrote in message
...

I want to take my telescope on my Alaskan in Aug 2010. I know the boat
travels in protected water(calm waters) and the sun doesn't set until
10:30pm. The boat will only be docked one day after sunset. Do you think
I will see anything fun and interesting with those conditions?

I have not found much information on this topic, so I am thinking it
doesn't happen much....



Are you thinking of using it for night sky viewing? Or long distance
viewing of things like distant mountains in the daytime? For night viewing
I wouldn't bother. The ship won't be nearly stable enough. The deck will
roll left to right and back almost constantly. Even if it's imperceptible,
it still happens, and it will be magnified by the telescope. You will lose
your image in less than a second or two.

For distant mountain viewing, you would have a shot while the ship is
docked. And if you use low power, you probably could while the ship is in
motion, by hand adjusting as necessary (probably almost constantly).

To be honest though... what I've come to realize is that wide angle is more
important than telephoto when I take digital photos. Especially with things
like mountains, street scenes, waterfalls, beaches, etc. Translation... you
may thing you'll view a lot with a telescope, but in the end it might not be
as useful as you think. On our recent trip to Norway, the mountains were
hundreds of times the size of the ship, and we were very close to the
mountains (few hundred feet). So the only way to capture something
interesting was with wide angle.

--Tom

On Wed, 21 Oct 2009 05:46:28 -0500, bioeve
wrote:


I want to take my telescope on my Alaskan in Aug 2010. I know the boat
travels in protected water(calm waters) and the sun doesn't set until
10:30pm. The boat will only be docked one day after sunset. Do you think
I will see anything fun and interesting with those conditions?

I have not found much information on this topic, so I am thinking it
doesn't happen much....

I agree with other posters that the field of view of a telescope is
much too small to be useful on a cruise ship because of the problem of
the rocking motion of the ship. However, a decent pair of binoculars
will be very useful on an Alaskan cruise! The captain, the naturalist,
and the park rangers that came aboard for our cruise of Glacier Bay
pointed out eagles, bears, mountain goats, sea lions, etc that were
often hard to see with the naked eye but were clearly visible with
binoculars. I found that a modern digital camera with a wide zoom
range (12x, 18x or even 20x) was very useful. The wide angle was good
for the scenery and the telephoto was great for wildlife closeups. The
only real drawback was the shutter delay. You had to try to anticipate
the action when a whale would breach or a glacier would calve. If you
are interested, you can check out our 2007 Alaskan cruise photos at:
http://www.neufie.com/Alaska-2007/Al...K-07-3310.html

Jack Hamilton wrote:
If you're planning on stargazing, it's hard to find dark outdoor
places on modern ships. There are lights, or the reflection of
lights, everywhere.

If something unique is happening up in the cosmos, the captain of the
ship will turn out all the outside lights and they will ask everyone to
turn off the lights on their balconies. About 13-14 yrs ago I went on a
cruise and this happened.


Becca