For the Beginner
The. novice. should. begin. by. spending. some. time.
practicing.viewing.land.objects.during.the.daytime.with.
the.Astroscan..Even.though.the.image.appears.inverted.
(see.the.section.on.“Terrestrial.Use”.on.page.24),.you.
will.gain.valuable.experience.in.handling.the.telescope,.
focusing.the.eyepiece,.using.the.finder.and.other.basic.
operations..
Getting Used to the Dark
When. you. first. begin. observing. at. night. you. probably.
won’t. be. able. to. see. very. much. except. for. brighter.
objects..That’s.because.your.eyes.aren’t.yet.used.to.the.
dark..The.full.process.of.“dark.adaptation,”.as.it’s.called,.
takes.about.an.hour,.although.you’ll.be.able.to.see.a.lot.
more.than.you.could.at.first.within.5.minutes.or.so..Give.
your.eyes.10.or.15.minutes.in.the.dark,.and.preferably.
longer.before.you.go.seeking.faint.targets.like.nebulae.or.
galaxies..You.can.pass.this.time.quite.enjoyably.looking.
at.some.of.the.brighter.sights.first,.such.as.the.planets.
and.double.stars.and.then.viewing.fainter.objects..This.
allows.the.eyes.to.dark-adapt.naturally.as.you.observe..
(If.the.weather.outdoors.is.cold,.you.can.get.your.“night.
eyes”. more. comfortably. by. staying. indoors. with. your.
eyes.closed.or.sitting.in.a.dark.room.).If.you.use.a.normal.
flashlight.or.penlight.to.look.at.star.charts.or.make.notes.
at. the. telescope,. its. excessive. brightness. will. destroy.
your.dark.adaptation..Always.use.a.red.LED.flashlight.or.
a.light.covered.with.a.red.filter.
Cooling Down the Astroscan
When. you. take. your. telescope. from. wherever. it. has.
been.stored.and.set.it.up.outdoors.for.use,.you’ll.have.
to.wait.for.it.to.become.thermally.stabilized.or.“cooled.
down”. –. that. is,. for. the. mirrors,. lenses,. and. air. within.
the.tube.and.ball.to.reach.the.outside.air.temperature..
Until.normalization.is.achieved,.there.may.be.noticeable.
image. distortion.. How. much. time. this. takes. depends.
upon.the.season.(i.e.,.longer.in.the.winter.because.of.the.
greater.indoor/outdoor.temperature.difference),.and.the.
size.and.type.of.telescope..Some.large.backyard.scopes.
may.need.an.hour.or.more.to.come.to.equilibrium.on.a.
cold.night!.But.for.a.relatively.small-aperture.instrument.
like.the.Astroscan,.this.typically.requires.only.10.or.15.
minutes. (again. depending. on. conditions).. And. in. any.
case,. image. distortion. is. not. as. obvious. at. such. low.
powers.as.the.Astroscan.uses..When.you.set.up.your.
Basic Operation and Viewing Hints
Look through the eyepiece with both eyes open.
telescope,.be.sure.to.remove.the.cap.from.the.end.of.
the.tube.(actually.from.the.dew/light.shield.–.see.page.
10). to. allow. the. night. air. to. reach. the. optical. window..
Conversely,.be.sure.to.cap.the.telescope.before.bringing.
it. back. indoors. to. prevent. condensation. from. forming.
on. the. window. due. to. the. temperature. difference..
(Should.you.forget.to.do.this,.before.capping.it,.simply.
let.the.telescope.be.exposed.to.the.inside.air.until.the.
condensation.evaporates.as.the.scope.warms.up.)
Looking Through the Astroscan
Looking.into.the.eyepiece.is.easy.and.doesn’t.tire.your.
eyes.when.done.properly..Try.to.keep.both.eyes.open,.
look. straight. ahead,. and. position. your. observing. eye.
so. that. the. entire. field. of. the. eyepiece. lights. up. with.
an.image..“Not.too.close.and.not.too.far”.is.the.rule..If.
you.wear.glasses,.they.will.sit.just.above.the.eyepiece.
when.your.eye.is.at.the.best.distance..If.you.don’t.wear.
glasses,.you’ll.find.the.optimum.distance.is.about.one-half.
inch.away..(In.both.cases,.this.really.depends.upon.the.
eyepiece.in.use.).Your.eye.should.not.actually.touch.the.
eyepiece.lens,.but.at.the.same.time.it.must.be.centered.
on.the.emergent.light.beam..This.is.difficult.to.do.when.
your.eyes.are.not.dark.adapted..But.once.they.are,.you’ll.
notice.that.the.sky.typically.seen.in.the.telescope.is.not.
really.black.but.a.rather.luminous.gray.due.to.sources.
like.light.pollution.and.moonlight..Using.this.illuminated.
area.as.its.target,.your.eye.will.automatically.center.on.
the.eyepiece..If.desired,.you.can.cup.your.hand.around.
the.eyepiece.to.serve.as.a.guide.until.you.get.your.eye.
centered. on. the. light. beam.. (See. also. the. section. on.
“Using.the.Rubber.Eyeguard”.on.page.10.).
