u/Entire_Foundation960

If you have a Dobsonian that has a compression ring only on one side of the focuser, then the collimation you do with a collimation cap is not going to be accurate.

If you have a barlow lens that can be unscrewed, it can get much easier. Put the collimation cap on top of the barlow and remove the lens. Put this barlow+collimation cap combination in the focuser and tighten the screw.

Now, do the collimation again. I have found that it is more accurate when done this way.

It's because when you use a collimation cap alone, you don't tighten the screw for the eyepieces. When you tighten the screw, the eyepiece moves towards the right a little bit, thus changing the configuration of the collimation.

I usually carry my 8" Dob by separating it into two parts. When I set the optical tube down, I squat, and when I stood up, my shoulder banged into the focuser.

After that, I couldn’t get the stars to reach sharp focus. I checked the collimation, and that wasn’t the problem.

So now I’m thinking maybe the bang caused it, although it wasn’t a very hard hit.

I checked the white guide lines on the focuser that are used for measuring, and I noticed the line was showing more on the right side than on the left. I applied a little pressure to the left side of the focuser, and now the line appears and disappears smoothly again.

Is this something to be concerned about? Have you ever banged your focuser before? If so, what problems did you face, and how did you solve them?

Through my 8" dob, Jupiter looked yellowish in colour. The bands were light brown.

Something different that I've noticed is that the great red spot (GRS) looked "saffron" in colour tonight.

Can the changes in atmosphere cause this colour difference? Because up until now, I've always seen the great red spot in "red" colour.

My dob took atleast 45 minutes to cool down. Because of the heat waves from my neighbour's house, I saw Jupiter as if I was looking at the reflection of it in water. The ripples were horrible. But later when my dob cooled down, I could see it clearly.

M3 appears as a fuzzy patch of light and nothing else. I used averted vision and it improved the view a little bit. I've also observed that the angle at which you see the object affects the amount of detail you see. For me, it's the 1 o clock position or the 2 o clock position. I couldn't resolve it into individual stars. My area is considered a suburb. But it might have something to do with the full moon tonight.

Finally, the 8" dob is actually very heavy when you are observing very seriously and get tired. It's a chore to even move the damn thing. If you don't exercise, don't go to the gym, please reconsider your decision of buying the 10" dob or higher lol.

You are not even ready for the 8". Sure, it's easy to move it out, but when you are tired, it can be very exhausting.

Why does this happen? When I defocus a star with a 25mm eyepiece, the donut doesn't look circular. It looks oval.

But when I'm doing a star test, as everyone recommends a high power eyepiece, I used high power. It looks circular this way.

So, what's wrong? My Explore scientific 8 inch Dobsonian came with the secondary slightly offset in a way that when I look through the collimation cap, the secondary and the focuser tube are not concentric. But the secondary looks circular.

If I try to center the secondary, it starts to look oval instead of circular from the hole of collimation cap.

Do you people with Dobs get the circular donut with all eyepieces or not? Help me.

I am seeing that there are two very minor dot scratches on my secondary mirror.

When I am looking through the eyepiece at night nothing seems wrong though.

Will this affect the performance of my scope?

I've recently bought an 8 inch f/5.9 Dob, and I have been beating myself up for two days for not buying a 10 inch. Then I found these websites. He sketched many DSOs with an Orion XT8 f/5.9 (same model as my Explore scientific 8" dob). I am indeed blown away by the sketches.

1. https://www.perezmedia.net/beltofvenus/archives/sg-messier.html

2. and also, another guy documented his DSO viewing experience with an 8" dob here
   https://xt8dob.wordpress.com/about/

3. This review by Zane Landers also helps: https://telescopicwatch.com/orion-8945-skyquest-xt8-review/

He says,

"The quality of many deep-sky objects I can view with the SkyQuest XT8 or any telescope, is heavily dependent on the light pollution I’m under.

Galaxies under dark skies look fabulous with the XT8; I have no trouble spotting the spiral arms of M51 and M33, the H-II regions of M82 and M101, and all sorts of dust lanes and details in several hundred of the brightest galaxies. But under light-polluted skies, the faint details and sometimes whole galaxies themselves completely vanish from view.

Many large, bright nebulae are similarly affected.

Open star clusters and globular star clusters, as well as smaller planetary nebulae, aren’t as affected by light pollution. Even from the suburbs, I’ve no trouble resolving many of the globular clusters like M13 and M15 into individual stars, and open star clusters are still majestic and colorful."

4. About the majestic books by Stephen James O' Meara (Deep sky companion series). I highly recommend checking them out. For all of his work, he used a 4 inch Genesis refractor with "NO FILTERS" for DSO observing. His sketches are more detailed than anything I've ever seen before.

5. From what I've learned here on the sub, many people claim that dark skies are more important for DSO observing. Dark skies are the reason why Stephen James was able to observe DSOs so well with his 4 inch refractor.

I recently bought an 8 inch Dobsonian. I have seen the moon and Jupiter with it and they look pretty amazing. Will I be satisfied with it for Deep sky observing? I don't have any high expectations because I know they won't show any colour or look anything like the High Resolution pictures.

I am willing to spend my time at the eyepiece, to identify details and roughly sketch them. I am willing to use every technique known like averted vision etc.

The question is, will I ever feel like, "Shit. I should have bought a bigger scope" ?