First scope arrived, help needed before tonight!

Chums

Ordered a Skywatcher Skymax90 from Sherwoods on Tuesday, arrived today
(Thu) via OpticalVision!

http://www.sherwoods-photo.com/sky_w...atcher_fs.html

Planetary observation tonight then, my first ever astronomy! And you
can guess where I'll be pointing my scope.

But being a total novice I have a couple of questions (the scope
didn't come with any instructions!)

I've slotted the right angled mirror into the scope. Correct? The
metal tube on the mirror slides into the rear end socket of the scope
and is held in place by nuts which are tightened. But how far do I
push to metal tube on the mirror in? All the way? A bit of the way? Is
how far it is pushed in relevant to anything?

The eyepieces supplied are (1.25"): 10mm & 25mm - which of these best
for looking at Mars tonight? And as above, how far to slide them in
before tightening nuts.

The 2x Barlow lens I've worked out goes between the right angle mirror
and the eyepiece. When do I use the Barlow and what for?

Very silly question #1 - but its bothering me : I've pointed the scope
at the house opposite, but can't get it into focus. Is this to be
expected?

Very silly question #2 - whatis the F8 knurled knob on the scope.

Very silly questio #3 - the eyepieces have threads running around the
eye-end of the eyepiece. What are these for?

Final call for advice - for looking at Mars tonight : any tips?

Yours in eager anticipation....



Mark Watson
Best SF - www.bestsf.net
Best SF reviews: classic and current short SF
Best SF Gateway: online short SF

Mark Watson wrote:
[...]
I've slotted the right angled mirror into the scope. Correct?

Correct.

The
metal tube on the mirror slides into the rear end socket of the scope
and is held in place by nuts which are tightened. But how far do I
push to metal tube on the mirror in? All the way?

Yes, all the way.

The eyepieces supplied are (1.25"): 10mm & 25mm - which of these best
for looking at Mars tonight?

Start with the 25, centre the image, then try the 10.

And as above, how far to slide them in
before tightening nuts.

All the way. Don't over-tighten the nuts -- you may strip the threads.


The 2x Barlow lens I've worked out goes between the right angle mirror
and the eyepiece.

Or between the diagonal (mirror) and the scope for x3.

When do I use the Barlow and what for?

See: http://astunit.com/tutorials/barlow.htm


Very silly question #1 - but its bothering me : I've pointed the scope
at the house opposite, but can't get it into focus. Is this to be
expected?

Depends how far it is away. I don't recall how close the Starmax 90 can
focus.


Very silly question #2 - whatis the F8 knurled knob on the scope.

I'm don't know what you mean by "F8". Where about on the scope is it? Is
it the focus knob (back of tube next to where the diagonal goes in)? Is
this the answer to your previous question?


Very silly questio #3 - the eyepieces have threads running around the
eye-end of the eyepiece. What are these for?

Eyecups?


Final call for advice - for looking at Mars tonight : any tips?

Align your finder with the scope on a distant fixed object (e.g.
Polaris, or a streetlight or TV antenna a mile or so away). Let the
scope cool down for an hour or so. Start at low mag. At high mag, be
patient if the image seems to wobble -- it could be the seeing. Wait for
it to get high before expecting to see a lot of detail. Remember that
learning to see takes time.

Good luck!

Best,
Stephen

--
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ Stephen Tonkin | ATM Resources; Astro-Tutorials; Astro Books +
+ (N51.162 E0.995) | http://www.astunit.com +
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

On Thu, 04 Sep 2003 13:31:25 +0100, Mark Watson
wrote:


But being a total novice I have a couple of questions (the scope
didn't come with any instructions!)

umm OK

The eyepieces supplied are (1.25"): 10mm & 25mm - which of these best
for looking at Mars tonight? And as above, how far to slide them in
before tightening nuts.

Probably the 10mm one with the Barlow lens see below

The 2x Barlow lens I've worked out goes between the right angle mirror
and the eyepiece. When do I use the Barlow and what for?

A Barlow Lens in your case 2x effectively doubles the magnification of
the eyepiece you are using, making your 10mm into a 5mm equivelant.
However with a doubling of power you also get a Loss in light entering
(reduced contrast) and a doubling of any optical faults already
present.
it goes into the drawtube (focuser) first, then the eyepiece slots
into it, and is held in place by (I think) the Knurled knob you are
refering to

Very silly question #1 - but its bothering me : I've pointed the scope
at the house opposite, but can't get it into focus. Is this to be
expected?

Yes, more so with the 10mm eyepiece, than the 25mm eyepiece, when I am
playing about with aligment, the nearest object I can focus on is a TV
ariel of the roof of a house some 700 yds away
Very silly question #2 - whatis the F8 knurled knob on the scope.


See above...

Very silly questio #3 - the eyepieces have threads running around the
eye-end of the eyepiece. What are these for?

Filters, thats where they screw into

Final call for advice - for looking at Mars tonight : any tips?

Yes, and some bad news as well.

Dont expect any miracles, like Mars to suddebnly be 1000x times
bigger, expect nothing more than at frist a fuzzy blob, and maybe not
even that.

Almost everyones first attempt at using a telescope is a disater for
them, and leaves them feeling that the money wasnt well spent.

But with a Little patience and understanding things will become
clearer.

The biggest problem (at least i have found) with people getting a
fairly powerful scope for the first time is targetting and tracking.
Mars will be a doddle to find in your finderscope, but then expecting
to see it in the main eyepiece will be a lot harder.

At about 20:00 the moon will be somewhere around the horizon, about 10
degrees above, start practising on that first, getting it in the
finderscope then viewing it in your largest eyepiece (25mm) and
gradullay reducing the eyepiece size .
try it like this
25mm
25mm + 2x barlow (12.5mm)
10mm
10mm + 2x barlow (5mm)
As you decrease the focal length (size) of the eyepiece, focusing
Becomes a very narrow band, that can be as little as 1mm of movement.
this is what i do, I find the moon, in particular the "sea of crisis"
and i use that feature to align the finderscope with my smallest
eyepiece, then I will go find mars.
i get it in the finderscope first, then I use my LARGEST eyepiece
which is a 40mm one, it gives me a very wide field, I center Mars in
the middle, then gradually reduce the eyepiece size keeping Mars in
the Middle.

At your highest mag, the earths rotation will make Mars zip across
your eyepiece in about 2 seconds.

So targetting and tracking practice are the things to get right first,
then focusing, and then after all thats done, after a while your eyes
will adjust to the scope and what at first looked like a fuzzy blob,
will slowly reveal more details to you.

Your 2 worst enemies are light and temp, its only 16:00 now, but
already my scope is set up and aligned for where Mars should be around
01:00 tommorow, this gives it time to aclimatise(sp?) and the temp
will drop very gradually throught the evening, although i will no
doubt have a play with it later.

For me it takes about 45 mins from the time I switch the lights off,
until my eyes have fully adjusted to things

Patience and practice are the two most important things

--
---
The two most abundant elements in the universe are Hydrogen and stupidity.
Why is the ratio of Hydrogen to Stupidity less in usenet than anywhere else in the universe?

wrote:
Very silly questio #3 - the eyepieces have threads running around the
eye-end of the eyepiece. What are these for?

Filters, thats where they screw into

Filters usually screw into the other end.

Best,
Stephen

--
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ Stephen Tonkin | ATM Resources; Astro-Tutorials; Astro Books +
+ (N51.162 E0.995) | http://www.astunit.com +
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

wrote:

Your 2 worst enemies are light and temp, its only 16:00 now, but
already my scope is set up and aligned for where Mars should be around
01:00 tommorow, this gives it time to aclimatise(sp?) and the temp
will drop very gradually throught the evening, although i will no
doubt have a play with it later.

Is this wise?

I had a look at the Sun at about 2pm (ever so quiet at the moment).
I've just brought the scope in and it is very hot. It will cool much
quicker indoors than out and will reach a useable temperature quicker
if I take it out somtime when it is a tad cooler outside than indoors.

Cheers

Martin

--------------
Martin Frey
N 51 02 E 0 47
--------------

wrote:
A Barlow Lens in your case 2x effectively doubles the magnification of
the eyepiece you are using, making your 10mm into a 5mm equivelant.
However with a doubling of power you also get a Loss in light entering
(reduced contrast) and a doubling of any optical faults already
present. it goes into the drawtube (focuser) first,

You are likely to be misleading Mark with this statement. The Skymax
range are MCTs. They do not have drawtubes, and focusing is achieved by
moving the primary by turning a small knob on the rear cell.

Best,
Stephen

--
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ Stephen Tonkin | ATM Resources; Astro-Tutorials; Astro Books +
+ (N51.162 E0.995) | http://www.astunit.com +
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

Mark,

I have been trying a few good sources in order to get more info on the
focus range of your scope. I've still not found it, but this review may
be of interest, especially the bit about collimation:
http://www.cloudynights.com/reviews2/starmax90mm.htm

FWIW, David Knisely is an experienced and very discrimintating observer.


Best,
Stephen

--
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ Stephen Tonkin | ATM Resources; Astro-Tutorials; Astro Books +
+ (N51.162 E0.995) | http://www.astunit.com +
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

On Thu, 04 Sep 2003 16:30:27 +0100, Martin Frey
wrote:

wrote:

Your 2 worst enemies are light and temp, its only 16:00 now, but
already my scope is set up and aligned for where Mars should be around
01:00 tommorow, this gives it time to aclimatise(sp?) and the temp
will drop very gradually throught the evening, although i will no
doubt have a play with it later.

Is this wise?

Works for me see below

I had a look at the Sun at about 2pm (ever so quiet at the moment).
I've just brought the scope in and it is very hot. It will cool much
quicker indoors than out and will reach a useable temperature quicker
if I take it out somtime when it is a tad cooler outside than indoors.

Oddly enough thats just what I have been doing.set it up around 2pm..
(nice grouping near the bottom of the Solar disk then), and had a look
at the sun, and I will wander in and out throughtout the evening, the
moon is just coming into my sight, and I might have a peep later.

The threory behind this is quite simple, the least amount of times I
have to move the thing, the least amount of times I have to check the
collimation, also by leaving out for the rest of the evening, the temp
falls gradually, and I dont get thermal shock, or heaven forbid
condensation problems.
If the temp drops too low (less than 10c) the fans and heaters will
kick in automatically.

Also by checking and aligning it now i dont have to ****ball about in
the dark, and risk loosing my night vision.
--
---
The two most abundant elements in the universe are Hydrogen and stupidity.
Why is the ratio of Hydrogen to Stupidity less in usenet than anywhere else in the universe?

wrote:

Oddly enough thats just what I have been doing.set it up around 2pm..
(nice grouping near the bottom of the Solar disk then),

Not from where I was looking - very sparse from Romney Marsh (ah the
poetry of that)

See:

http://www.solar.ifa.hawaii.edu/MWLT/Today/latest.jpg

Still yesterday's image as I post this, but only the rotational change
since then visible.

Cheers

Martin

--------------
Martin Frey
N 51 02 E 0 47
--------------

On Thu, 4 Sep 2003 16:41:31 +0100, Stephen Tonkin
wrote:

Mark,

I have been trying a few good sources in order to get more info on the
focus range of your scope. I've still not found it, but this review may
be of interest, especially the bit about collimation:
http://www.cloudynights.com/reviews2/starmax90mm.htm


Thanks Stephen, and all the others who've replied. I've had a quick
shufty at the article above and will read this weekend - I'm only
understood about 1 word in 4 at a quick glance!

I've sorted out the focussing - it was just a question of getting the
right angle mirror and the lenses in the right position, and figuring
out that the f8 knob -was- the focus knob and that i had to twiddle it
a long way round to get a focus.

A quick trip into town to buy a sturdier tripod proved necessary, but
at least so far we've had an impressive closeup up of a sunflower leaf
at the far end of our garden. And the sky in Colchester is pretty
clear at present (tempting fate.....)

I think I'll leave collimation to the weekend!

Once again, thanks to everybody. From weenie binoculars to the right
starter telescope in about 10 days, thanks to uk.sci.astronomy
members!

Mark Watson
Best SF - www.bestsf.net
Best SF reviews: classic and current short SF
Best SF Gateway: online short SF