Puzzled...

[Hawkian]

Forgive the newbie question but...

So I've taken out my newtonian reflector twice now and I've had no luck being able to see anything. All i see is a dark bluish circle (which i assume is the mirror) and some faint lines crossing through it but no stars. I will admit to being very green with telescopes and I thought I would see stars pretty much by pointing and shooting. So far, not so...

I am going to give it another go this week since the clouds are supposed to clear out. I was wondering... what are those metal bars that criss-cross the tube called and am I supposed to see them through the eyepiece when I look at an object?

[Schorhr]

Hello,

did you try observing something during the day? Just make sure it's away from the sun or reflecting surfaces, to avoid damaging your eye!

Usually you should place a eyepiece into the focuser, look through the finder to roughly point the telescope tube at the target, and then look through the focuser and turn until the mirror/disk disappears and you see a sharp image.

[John]

Hi,

No problem about the question - it's one I've seen a few times.

I reckon the lines you are seeing are the shadow of the vanes that support the secondary (smaller) mirror. You are not supposed to see them as they are normally out of focus when you are looking at an astro object so this suggests to me that your scope is well out of focus.

Could you say what scope you have and what eyepiece you are using with it as this will help diagnose the issue further.

[nmoushon]

It sounds like your scope might be out of collimation and focus. Try looking at the moon first since it big and easy to find.

The metal bars hold the secondary mirror in place. You will not see them directly when looking through your eyepiece. You will however see the effects they leave which will be the star pikes around stars...once you get the problem fixed.

[Schorhr]

I forgot: ObJects that are real close may not get into focus, so a near tree or building may be too close.

The cross would be the rods/wires holding the secondary mirror.

if you are out of focus too much they will be visible.

[Scott]

A picture of your scope set up might be helpful in working out the problem . One common fault is putting the 2" AND the 1.25" adapters in at the same time. Also make sure the locking screw on the focuser isn't locked. It may "feel" like the foccuser is moving while  staying put. Sorry if these are too obvious but I'm assuming a minimum knowledge. good luck and don't give up. it's probably something really simple

[John]

A picture of your scope set up might be helpful in working out the problem . One common fault is putting the 2" AND the 1.25" adapters in at the same time. Also make sure the locking screw on the focuser isn't locked. It may "feel" like the foccuser is moving while  staying put. Sorry if these are too obvious but I'm assuming a minimum knowledge. good luck and don't give up. it's probably something really simple

Yes, thats my hunch as well. It's a common issue with the Skywatcher newtonians and the instruction manual is not any help at all on how to use these adapters 

[Hawkian]

Thanks all... and don't apologize for anything that may sound too obvious to you... chances are it will help me.

My scope is a Sky Watcher 130mm on an equatorial mount. I bought it used from a specialized store for $200. I actually set it up in the basement the first night and was able to point it to the far side of the basement wall (about 50 feet away) and focus on an object that. I used the object to align the scope and the finderscope (a telrad finderscope). All seemed ok and i could see tha object quite clearly and in the expected upside-down and inverted position. Sorry I don't have pictures of it since I am currently at work (and probably should be working...  ).

I was going to start with looking at the moon when I first purchased it. I figured I'd start with a bigger object and work my way to smaller the ones later. But it was a new moon so I picked Polaris as a target. No luck seeing anything... even after I realized there was a focusing knob I wans't using after about an hour... hehe

Anyway the moon will be out tonight so I should be able to give it another go. I should add that I am trying this from my back deck which is in an area that is relatively polluted by light. I understand that this can limit what you can see with the scope but I should still be able to see a star through my Telescope if I can see it with the naked eye i would think no?

[Schorhr]

Yes, if you can see it with your eyes, you will see it with the telescope. What is your lowest magnification (focal length devided by eyepiece (millimetres)).

If the light polution is strong, there won't be many stars inbetween the visible ones. You may just have a hard time with lets say 50x magnification finding the star if the telrad/finder alignment is a bit off (due to aligning it on something closer to "infinity").

Also if you have not focused, the stars will get larger and eventually not be visible. If you reach focus the stars will become visible;

Don't give up! :-)

The moon should be easy to find, and is great practice.

[brantuk]

The first thing to do is pop the 25mm eyepiece in. This is a low power eyepiece so you will definitely see something. However you will need to find the focus point for your telescope. Start with the focuser full in and wind it back very slowly. You'll start by seeing the view you have already described.

Point it at the moon using the finder scope, as you wind the focuser back you'll see a round circle of light - wind back a bit more and the circle will get smaller until the moon starts to appear. Finally you'll wind back until it is very sharp in the eyepiece.

As you do the focusing, periodically check the finder to make sure the moon is still in the center - adjust the scope using the slo mo controls to keep it central. Everything depends on your object being central in both finder and scope eyepiece.

The 130 is a very capable scope, so good luck and let us know how you get on.

[Scott]

Hawkain,

Until you are sure you're achieving focus at infinity (the distance of the stars) and not at 50 feet (way too close) it'll be hard to find stars. you can either focus the scope during the day on a distant object (preferably around 500 yards) or if it must be done at night, on the moon will be a lot easier. aligning telrad should be done at a fair distance as well. Do you understand what we are saying when we say that only one adapter should be used at a time?

[Hawkian]

Lowest magnification is 26x (650 / 25)... does that sound right?

[ScottS]

Is your OTA really aligned with the finderscope? 50ft may not be far away enough. Try aligning on something much farther away.

[Hawkian]

Do you understand what we are saying when we say that only one adapter should be used at a time?

Do you mean only one eyepiece without the barlow inserted? If so then yes. If not then no.

[Scott]

Do you mean only one eyepiece without the barlow inserted? If so then yes. If not then no.

No, the adapter is the piece that the eyepiece or barlow is placed in. they come in 2" and 1.25"  so you can use different size Eyepieces. These adapters go directly into the focuser and the eyepiece goes into the adapter. (Hard to explain without pics sorry

[John]

Now I see the scope involved I realise that the adapter issue might be a red herring as the scope only uses 1.25" eyepieces I think.

50 feet is probably far too close for the scope to focus on anything - the minimum for newtonians is often hundreds of feet away.

You need to use the focus knobs you have now found to move the tube with the eyepiece in it in and out to achieve sharp focus. Use the 25mm eyepiece to start with and wait for some stars to test it on.

The finder scope needs to be accurately aligned with the main scope to be useful. Do this in the daytime (NOT towards the Sun) but use an object a mile or so away to align the finder and the scope on.

When a star is in focus it will look like a tiny point of light - if you are seeing a disk of any size when looking at a star then the scope is not in focus. 

[Moonshane]

focus on the wall 50 feet away and then leave it until night time in the same position. then wind the focuser in the opposite direction (presumably inwards) until you see sharp stars. it will be maybe half way through the travel. you'll need to leave the scope for maybe 30 minutes to get the best out of it.

[Scott]

Now I see the scope involved I realise that the adapter issue might be a red herring as the scope only uses 1.25" eyepieces I think.

Ahh, I see....very sorry for adding to the confusion

[Hawkian]

And then there were stars!

Thank you all for all the attempts at helping. The very night of when I started this post I took the scope out again. Instead of trying to fight with the EQ mount and using the finderscope to point at things, i decided to simply loosen up the mount and move the scope around until I could find something. I was seeing large faint blue dots but nothing else... until I played with the focusing knob and saw (you'll never believe what)... Stars!

The bottom line here is that there's nothing wrong with the scope, but there appears to have been something wrong with the scope operator not being able to use a simple focusing knobby... (and yes... this is embarrasing).

Oh and by the way, the moon looks absolutely awesome in my scope but man does that thing look beaten up or what?

Thank again folks!

[tdmodels]

Excellent news Hawkian.
Some great objects to view at this time of year, like our nearest neighbour galaxy M31, Orion Nebula, M27 dumbbell, M45 Pleiades, just for starters.  I can recommend the free software Stellarium which will help you find these objects and loads more.

 

[brantuk]

Congrats Hawk - glad you're sorted now - have fun with your new toy!

[Hawkian]

Thanks for the suggestion Tim. I actually downloaded Stellarium about 2 months ago to get myself acquainted with the night sky before buying the telescope. It is an awesome piece of software indeed!

[bingevader]

Excellent news!

No need for embarrassment, you've got to start somewhere and you're not the first and won't be the last.

My dob lived in the conservatory for a few months before giving up and making its way to the shed.

Things used to get twiddled all the time by the children and I'd often take it out of an evening and think it was broken again before working out what they'd upset this time.

He's happy now, in the shed!

Cheers

[Schorhr]

Great! I hope you'll have many nice observations with your telescope!

[Schorhr]

Great! I hope you'll have many nice observations with your telescope!