eclipse trip query

Hi guys
I'm off to china in a couple of weeks, to see the total eclipse of
1/8/08, weather permitting! I was thinking of making a solar filter
for my 10x50 binos from Baader reflective filter material that's
available very cheaply. The binos are a very old pair that have always
served me well for astronomy, but I had wondered about trying to pick
up a short focus refractor as an alternative. Anybody know anything
about Nipon telecopes? There seem to be regular versions of a 70mm
"rich field" 70x300 refractor available on eBay for around £35. The
advantage of this scope is it will fit on a camera tripod, which I
will be taking anyway, and it only weighs 650g. It's a terrestrial/
astro scope naturally at that price, but I guess that isnt a problem.

Any thoughts? There are loads of nice starter scopes of 60 or 70mm of
course, but they are usually about 700mm or more focal length, and so
too long for packing in a normal suitcase!

Should I stick to my binos, or go with eBay?

Paul
Lancs

doc_paul wrote:

Should I stick to my binos, or go with eBay?

Stick to your binos IMHO

--
Abo

Have a great trip, let us know how you get on.

I am leading a tour to China for the 2009 eclipse so would value your
comments on the 2008 trip

Thanks

Andy
--
Mr Andrew R Green BSc(Hons) FBIS, FRAS
Director & Lecturer, StarDome - Astronomy & Astronautics
Director Anglo-Australian Astro Education Partnership



"doc_paul" wrote in message
...
Hi guys
I'm off to china in a couple of weeks, to see the total eclipse of
1/8/08, weather permitting! I was thinking of making a solar filter
for my 10x50 binos from Baader reflective filter material that's
available very cheaply. The binos are a very old pair that have always
served me well for astronomy, but I had wondered about trying to pick
up a short focus refractor as an alternative. Anybody know anything
about Nipon telecopes? There seem to be regular versions of a 70mm
"rich field" 70x300 refractor available on eBay for around £35. The
advantage of this scope is it will fit on a camera tripod, which I
will be taking anyway, and it only weighs 650g. It's a terrestrial/
astro scope naturally at that price, but I guess that isnt a problem.

Any thoughts? There are loads of nice starter scopes of 60 or 70mm of
course, but they are usually about 700mm or more focal length, and so
too long for packing in a normal suitcase!

Should I stick to my binos, or go with eBay?

Paul
Lancs

An astronomical thread? Good grief!

If you get involved in telescopes you need a steady tripod as well.
Which usually means heavy! I used my little 90mm Vixen refractor and
heavy Bogen video tripod for the last solar eclipse. I took pictures
with a handheld digital camera held up to the low power eyepiece.
(26mm and 15mm) Getting the kit to the top of the nearest grassy hill
to catch the event rather low in the very early morning sky was hard
work.

I hadn't bought my even smaller Bresser Skylux 70mm back then but it
is far too reflective internally (before modification) for Solar work
and the equatorial mounting is far too heavy for air travel and has no
electric drive anyway. A simple home-made cannon-style Dobsonion altaz
fork mounting made of thin plywood and balsa might work resting on a
wall with a borrowed Chinese brick, boulder or sandbag for a
counterweight. But the Bresser Skylux will need very careful internal
blackening to make it worth taking. Otherwise it's not a bad little
scope with the addition of some better (more expensive) eyepieces. You
could carefully remove the massive dewshield to save a lot of wasted
space in your luggage then it would go in almost any suitcase.

If you just take your binoculars make sure you have some spare Baader
solar filters and store them so they can't be damaged by other things
in your luggage. I'd suggest you put them into a cardboard tube with
easily removable ends something like poster packing. Put something
soft between each filter to stop them rubbing together under
vibration. One of my home made telescope filters has worn through the
reflective coating of the foil where it meets the dewshield and needed
local repair with black tape. I should have used a simple cardboard
ring spacer inside the filter to avoid this happening. I now store my
solar filters in clear plastic, screw top, kitchen storage containers
to keep them safe when not in use.

If you are taking a digital camera have spare *fully charged*
batteries and a large enough memory card to be able to take lots of
highest res snaps without changing cards. Make absolutely sure that
your batteries work well before leaving. Recharge and discharge them a
number of times to check for total reliability. There are some garbage
(even big name) batteries out there. I bought some spare Sony
batteries for the Mercury transit and the damn things wouldn't hold a
charge from new! £18 for two AAs! So I was limited to a pair of dying
batteries for a once in a lifetime event! Use a standard slow
charger to avoid frying your batteries. My Cannon paving-slab-style
battery seems to last for months. I bought a spare and have only ever
done one battery swap (from memory) in six months despite taking
pictures every single day.

Set your camera to highest resolution and switch digital zoom off in
the menu so you are not tempted to use it. Steady the camera on
something to take sharp, useful shots which can be enlarged later at
the computer. Zooming digitally to take large fuzzy images is a total
waste of effort. Use only optical zoom. You can set your camera to
hold the lens out without auto retraction it will avoid wasting time
waiting for it to "wake up" between shots. You could even make a
little push-on Baader filter for the camera if you can safely fix the
lens in the extended position in the menu. See how it copes being
pointed straight at the Sun without a filter but don't leave it for
too long.

Remember that you only get one chance at an eclipse. There are no
action replays. Practice a lot before before you go and have your
backup kit ready to hand and practice with the stuff you are actually
taking. Practice with the sun at the same height it will be on the big
day. Discovering that you need a shade or baseball hat for your head
in the middle of the eclipse is far too late. Have a lanyard for your
glasses or sunglasses so you can drop them onto your chest without
having to think about putting them down to use the binos or camera.
Discover how long the cord needs to be before you leave. If you wear
glasses think about how you are going to handle that problem before
you go. Most people don't need their glasses when using binos. Do you?
You may be like me and need glasses to see the camera viewfinder
screen clearly. If you are swapping between camera and binos you need
to practice that too.

Know *exactly* how high the sun will be during the eclipse before you
go. So you will be prepared for continuous viewing at that viewing
altitude. Find something to rest your elbows on while seated if
possible so you have a nice steady view without tiring your arms. A
tree, pole, chair, gate or fence can be used to support the arms or
camera if necessary. A hotel sun lounger or garden chair (with arms)
might be all you need depending entirely on the height of the sun
during the eclipse. If all else fails sit on the ground with your
elbows on your knees to support the binos or camera.

An eclipse is magical! Enjoy your trip. But do practice before you go
to avoid disappointment.

Hey!!! Thanks guys for really useful responses. I feel a bit
embarrassed even to have asked about some of the very likely rubbish
scopes they have on eBAY!!
Chris, that was a fantastically useful reply - thanks a million for
taking the trouble to put it all down for me. I'm still not fully
decided about the scope idea.
I think finally the only option I would consider would be the
Skywatcher Mercury 705 short focus f7.14 70mm, but as you say, the
tripod steadiness is going to be
the major problem.
My main camera will be a Nikon D80, so I think the priority is
probably to take a half decent tripod for that, and use Baader film
with practice beforehand if we ever see the
sun here in Manchester!! Thanks for the tip about spare batteries. I
may well also take a Canon G5, which is a great little auto/manual
compact. We do have to survive
a minibus tour round some very hot Silk Road destinations with
Explore, so obviously we don't want to be encumbered by too much
stuff. Also, totality is barely 2 minutes,
and I certainly don't want to be messing about with technology for the
entire time. I think the priority should be to experience the thing
rather than to record the experience.
I was in Penzance in the rain in 1999, and have been longing to see
totality ever since. At least this chinese semi-desert area has pretty
good weather prospects, which is why
we decided to go there rather than somewhat (!) more accessible
Novosibirsk.

Thanks again

Paul

Explore is the company that I am escorting the tour for in 2009.

Looking forward to it greatly

Cheers

Andy

Mr Andrew R Green BSc(Hons) FBIS, FRAS



"doc_paul" wrote in message
...
Hey!!! Thanks guys for really useful responses. I feel a bit
embarrassed even to have asked about some of the very likely rubbish
scopes they have on eBAY!!
Chris, that was a fantastically useful reply - thanks a million for
taking the trouble to put it all down for me. I'm still not fully
decided about the scope idea.
I think finally the only option I would consider would be the
Skywatcher Mercury 705 short focus f7.14 70mm, but as you say, the
tripod steadiness is going to be
the major problem.
My main camera will be a Nikon D80, so I think the priority is
probably to take a half decent tripod for that, and use Baader film
with practice beforehand if we ever see the
sun here in Manchester!! Thanks for the tip about spare batteries. I
may well also take a Canon G5, which is a great little auto/manual
compact. We do have to survive
a minibus tour round some very hot Silk Road destinations with
Explore, so obviously we don't want to be encumbered by too much
stuff. Also, totality is barely 2 minutes,
and I certainly don't want to be messing about with technology for the
entire time. I think the priority should be to experience the thing
rather than to record the experience.
I was in Penzance in the rain in 1999, and have been longing to see
totality ever since. At least this chinese semi-desert area has pretty
good weather prospects, which is why
we decided to go there rather than somewhat (!) more accessible
Novosibirsk.

Thanks again

Paul

Good stuff! AND a 6 minute eclipse ..... but the weather prospects
perhaps better in 08? So do you have to be really clever to escort a
group? Do they want an expedition doctor??? :-)

Paul

Hi Chris

I wasn't trying to correct you. Merely disguisuing the fact that I had
no useful answer to your question.

Well disguised.

In astronomical terms I punching way above my weight here which may be
confusing you and DEFIANTLY is confusing me.

Good point (I stand corrected as usual) but it isn't visible to us (yet)
which is why it's dark isn't it?

Following your logic the radiation from dark matter (if any) would
need to have a very low velocity not to have got here by now from the
nearest object containing dark matter.This assumes you had a detector
which could sense its presence once it got here if it was not in the
form of light.

I meant we can't detect it yet not it hasn't reached us yet. I mean, at the
speed of light, we've been receiving light from below naked eye visible
stars for a long time but it's only till the relatively recently that we
made
scopes to see them. The energy from dark matter (I agree, if any) could be
here already but we don't have the detectors ready for it yet.

Q: Images of distant galaxies contain both light and dark matter that
is
only visible to us...

To continue to show my lack of ability in this field one of my thoughts was
that it's infinitely fast. The dark areas on the film/CCD are dark the
instant you open the shutter/???, indeed, even before you open the shutter.
And yes, I really should join the 21st century and go digital. The energy
from dark matter doesn't turn these areas dark or some bright spark would've
spotted this and we could detect it and it would no longer be dark.

Thanks for the reply and making me think (though I could do without the
headache it's given me) ;-(

Neil

Thank fu.. err I mean, thank goodness that's finally uploaded.

Hi Chris

Sorry for the delay in responding but I've been fighting a loosing battle my
my PC. Seem to have got it now though.

Neil