<p>The number you read on the “lens” (called an eyepiece) is its own focal length. It will give you a magnification that is equal to that of the telescope divided by this amount. I can’t seem to find a definitive list of specifications for the telescope, but it seems to have 800 mm of focal length. So if you use an 20 mm eyepiece, you magnify 800 ÷ 20 = 40×, and with a 10 mm eyepiece, it’s 800 ÷ 10 = 80×, and so on.</p>
<p>What you want is to use the SMALLEST magnification. Because the view finder is not necessarily aligned with the main telescope, maybe it doesn’t point in exactly the same direction. Using the smallest magnification increases your chances of finding the object in the main telescope, as the field of view is then wider.</p>
<p>I would suggest moving in small circles, gradually increasing in size (spiral) around the position. You should be able to see the object in the main telescope at some point.</p>
<p>Also, start with an easy, large target like the Moon.</p>
<p>There may be other reasons, but it’s difficult to know without being there with you when you use your telescope.</p>
<p>Good luck!</p>

CC BY-SA 4.0
2024-08-18T23:00:04.063Z
Often it is easiest to get familiar with a new telescope by just looking at distant objects on the horizon during the day-- looking at the moon is the closest analog to that at night.  If you can't see *anything*, it usually means your scope is badly out of focus.  During the day looking at distant objects that will be more obvious.  If you get the focus right on those, it should be a small (or no) adjustment to focus on astronomical objects.
antlersoft
CC BY-SA 4.0
2024-08-13T18:05:47.173Z
2024-08-13T18:05:47.173Z
Pierre Paquette
<p>Chances are it's that you are too far out of focus, and at night there's not much to look at (unless there's a Moon).</p>
<p>Just take your telescope out during the daytime, or look through an open window (or one with nice, flat glass if necessary, no window screen!) That way you have plenty of light.</p>
<p>Look at a distant object, say a kilometer away or more if possible. If you look at something too close, the focus position you find will be many millimeters further out (away from the telescope) than it would be looking at the stars.</p>
<p>Now you can start to move the focus in and out, you may have to move quite a lot before you start detecting contrast. Once you see something, keep going until you've found focus. Then use a ruler or piece of tape or something else to note the position.</p>
<p>Then at night, start at that focus and look at something bright like the Moon or a planet first.</p>
<p>And as <a href="https://astronomy.stackexchange.com/users/34758/pierre-paquette">PierrePaquette's answer notes</a> use the lowest magnification which will be the longest focal length eyepiece (the biggest number of millimeters).</p>
<h3>If you can not see anything during the daytime...</h3>
<p>even though you're pointed at a distant object and have run your focus in and out, then you may have a more severe alignment problem, either the primary mirror or the diagonal secondary mirror.</p>
<p><strong>And make sure the Barlow lens is not in the telescope!</strong> It comes with one. If you can't find it anywhere else, it might already be in there. Take out the eyepiece, you should easily see the diagonal mirror and the reflected image of the primary through the diagonal. If it looks demagnified - the barlow lens is still in the tube.</p>
<hr />
<p>And always remember, when viewing during the daytime, <em><strong>DO NOT POINT ANYWHERE NEAR THE SUN!</strong></em> Not even a nice sunset/sunrise. Your retina will thank you for being careful!</p>

CC BY-SA 4.0
2024-08-19T09:43:10.663Z
2024-08-19T09:51:43.573Z
2024-08-19T09:51:43.573Z
uhoh
<p>Starting to use a NG76AZ 75 mm x 700 mm Newtonian reflecting telescope I've put all the pieces together and find that when I start observing the sky with 2⁰mm lens nothing shows up. And any higher lens all seem to make the viewings darker. The view finder is all that seems to show objects in the sky. But when viewing from the image erector  nothing is visible. Can there be a problem with the alignment of the two viewings lenses?</p>

CC BY-SA 4.0
2024-08-19T09:54:50.580Z
edited the title; "[NG telescope](https://ell.stackexchange.com/q/147040/120483) sounds too judgmental. :-)
uhoh
<telescope><amateur-observing>
I've set up my NatGeo telescope but can't see anything from the main telescope lens after using the view finder to focus on an object
Bill Oregan
# I've set up my NatGeo telescope but can't see anything from the main telescope lens after using the view finder to focus on an object

(Asked by: username_0 on 2024-08-13)

Starting to use a NG76AZ 75 mm x 700 mm Newtonian reflecting telescope I've put all the pieces together and find that when I start observing the sky with 2⁰mm lens nothing shows up. And any higher lens all seem to make the viewings darker. The view finder is all that seems to show objects in the sky. But when viewing from the image erector nothing is visible. Can there be a problem with the alignment of the two viewings lenses?

**Tags:** telescope, amateur-observing
> **Comments:**
> **username_1**: edited the title; "[NG telescope](https://ell.stackexchange.com/q/147040/120483) sounds too judgmental. :-)  

---

## 2 answers

### Answer by username_2 on 2024-08-13. Score: 4

The number you read on the “lens” (called an eyepiece) is its own focal length. It will give you a magnification that is equal to that of the telescope divided by this amount. I can’t seem to find a definitive list of specifications for the telescope, but it seems to have 800 mm of focal length. So if you use an 20 mm eyepiece, you magnify 800 ÷ 20 = 40×, and with a 10 mm eyepiece, it’s 800 ÷ 10 = 80×, and so on.

What you want is to use the SMALLEST magnification. Because the view finder is not necessarily aligned with the main telescope, maybe it doesn’t point in exactly the same direction. Using the smallest magnification increases your chances of finding the object in the main telescope, as the field of view is then wider.

I would suggest moving in small circles, gradually increasing in size (spiral) around the position. You should be able to see the object in the main telescope at some point.

Also, start with an easy, large target like the Moon.

There may be other reasons, but it’s difficult to know without being there with you when you use your telescope.

Good luck!

> **Comments:**
> **username_3**: Often it is easiest to get familiar with a new telescope by just looking at distant objects on the horizon during the day-- looking at the moon is the closest analog to that at night.  If you can't see *anything*, it usually means your scope is badly out of focus.  During the day looking at distant objects that will be more obvious.  If you get the focus right on those, it should be a small (or no) adjustment to focus on astronomical objects.  

---

### Answer by username_1 on 2024-08-19. Score: 1

Chances are it's that you are too far out of focus, and at night there's not much to look at (unless there's a Moon).

Just take your telescope out during the daytime, or look through an open window (or one with nice, flat glass if necessary, no window screen!) That way you have plenty of light.

Look at a distant object, say a kilometer away or more if possible. If you look at something too close, the focus position you find will be many millimeters further out (away from the telescope) than it would be looking at the stars.

Now you can start to move the focus in and out, you may have to move quite a lot before you start detecting contrast. Once you see something, keep going until you've found focus. Then use a ruler or piece of tape or something else to note the position.

Then at night, start at that focus and look at something bright like the Moon or a planet first.

And as [PierrePaquette's answer notes](https://astronomy.stackexchange.com/users/34758/pierre-paquette) use the lowest magnification which will be the longest focal length eyepiece (the biggest number of millimeters).

### If you can not see anything during the daytime...

even though you're pointed at a distant object and have run your focus in and out, then you may have a more severe alignment problem, either the primary mirror or the diagonal secondary mirror.

**And make sure the Barlow lens is not in the telescope!** It comes with one. If you can't find it anywhere else, it might already be in there. Take out the eyepiece, you should easily see the diagonal mirror and the reflected image of the primary through the diagonal. If it looks demagnified - the barlow lens is still in the tube.

---

And always remember, when viewing during the daytime, ***DO NOT POINT ANYWHERE NEAR THE SUN!*** Not even a nice sunset/sunrise. Your retina will thank you for being careful!


---

