Help new Dobsonian owner

Question

I need a bit of advice. I purchased a Orion xt8 and a lens kit with a 2x Barlow 6mm 20 mm eyepieces and every time I try pulling things into focus / magnification or focus goes out the window recently purchased a 5x Barlow to try to get the images bigger. But I’m starting to get a bit discouraged as the only thing I can see in the sky is the moon. All others. Clusters. Andromeda. Mars I can not pull into focus to save my life.

I don’t know what I’m doing wrong. I see all these pictures of Andromeda from the same telescope and on mine I see dots. (Above picture is the most dots I could see near a cluster. But it’s not the cluster. I guess my question would be. How can I see objects in higher mag / detail. Andromeda is a dot like a star. So are all the planets.

And yes I know what to expect. I know things will look very blurry or out of focus. But only seeing star dots (when they are planets) concerns me.

Answer 1

I have experience using this telescope. It looks like you can focus correctly if you get a good view of the moon. You probably don't want more magnification (the Andromeda galaxy is comparable in size to the moon). It is easier to get and keep targets in the field of view with a low power eyepiece, and I suspect that is your problem.

Start with planets. Use your low-power eyepiece, 20 mm. Jupiter is the easiest to see as a disk, but it is unfortunately close to the sun right now so it is low in the west in the evenings. With your 20mm eyepiece, it should be quite obvious as a disk with satellites and you may be able to see bands.

Mars is quite prominent right now in the evening sky but it is smaller than Jupiter. Still, with your 20mm eyepiece, you should be able to at least tell it is a disk (and a bright orange one) if you have it in the view of the eyepiece. Once you have it centered in view of your 20 mm eyepiece, you can try switching to your high-power (6mm) and see if that reveals any more detail. Markings on Mars or quite subtle; often it looks like a featureless orange ball.

If your night sky isn't that dark because you are close to a city with its outdoor lights, it can be a challenge to get a good view of even spectacular "deep sky" objects like the Andromeda galaxy. Again, use your low power eyepiece and no Barlow lens. The core of the galaxy is much brighter than the extended glow around it, so it can appear star-like. Try looking at with "averted vision" (don't look directly at it, to use the more sensitive light-detectors towards the edge of your field of vision) to pick out the faint glow that surrounds the core. If you go to a dark sky location (one where you can really see the Milky Way) the XT8 can give a pretty impressive view of the galaxy where the elliptical outer glow will fill the FOV of your low-power eyepiece.

If it is hard for you to travel to a dark-sky location, you can try buying a deep-sky filter. This filter tries to block the specific wavelengths thrown into the sky by outdoor lighting. It makes everything you see through the scope dimmer and kind of green, but it can improve contrast on galaxies and nebula by making the background sky darker.

Answer 2

What is your location? If you're in a high-humidity or high-wind area, atmospheric turbulence will affect image quality as well.

How are you attaching the camera to the 'scope, and have you set up a remote shutter release? Any small vibrations will, again, affect image quality, and these effects are much more noticeable on small objects vs. the Moon.

Start, if you have them available, by sighting the planets with 8x or 10x binoculars. If you get clear images with them, then it's time to look at your 'scope's alignment -- it could be in focus but the elements not on-axis, leading to aberrations as well.