Aston

I did some more alligning today, the secondary was a slight bit off. Now the crosses align nicely

Seeing wasnt the best today, but i got out and took a look at Jupiter and was pleasently surprised, i could clearly see the color bands, and getting into focus was easy and distinct in comparison to earlier! I dont know if it was the collimation or the fact that let the telescope cool down for two hours, but im very happy with the results! Thanx for the help everyone

I got a Cheshire tube, and i think i got it right, the cross is fixed at the spot on the main mirror, and everything is centered in the scope. Does it look OK?

Waiting for the optics in the telescope to cool down is probably a good idea, i used the scope without any cooling down time. I did notice that when i used the "out of focus star" trick to look at the colimation, there was a boiling motion in the out of focus star, that looked like hot air turbulence.

After some tweeking with the secondary mirror i managed to get the dot on the main mirror to become more centered. The secondary mirror looks to be a bit off center(you can see the mounting screw) but i dont know if it affects viewing.

I used my 3d-printer to print a collimation cap, that was a good fit. I took an image through it, and its a bit off. The white center circle on the main mirror is ofset a bit, and one of the screws can be seen at 5 o'clock on the secondary mirror. But since i havent got any experience, i have no idea if this is too much, or if it is not noticeble.

Here is the image i took.

Thanx for the help, i will have a look at the links and try to change my viewing spot to somewhere with less housing. I took a picture down the eyepiece holder, is it possible to say from that weather the scope is collimated correctly or not?

I have a 10" dobsonian from Skywatcher, but im not happy with the image quality. I am able to focus "passed" max-focus(so its not that the truss tubes arent extended all the way), but im not getting crisp focus. Yesterday i was looking at Jupiter again, it was a clear night but i just saw jupiter as a bright blob, whit no bands or colors what so ever. I have tried this several different nights, with different eye-pieces, but cant get any detail out of the planets. I compared to my spotting scope(Vortex Razor HD 20-60x85), and got a much better image. Stars arent so easy to focus on, i cant get them to become just a spot without blurring out a bit. I have collimated with a cheap laser collmiator, and its spot on(it depends a bit on how you fasten the thing, its a bit wobbly), and when i do the out of focus star, i think im seeing the mirror in the middle of the blurr. Is my scope poorly collimated, or is there something wrong with it?

I was out observing through my new 10" dob in a Bortle class 4 area with almost no clowds and a temperatur of -10c. I collimated the scope and watched Orion nebula, Andromeda galaxy and even the M110 galaxy next to Andromeda, all looking good to me(stars well focused). When i got to mars(at approx 40 degrees inclination) the image was horrible, i tried both 9 and 4,5mm eyepieces, checked the collimation with an unfocused star and with my laser collimator, but everything was ok. Mars was smearing, unfocusable and the image had a lot of mirage. I could tell it was something big and round, but it had no other signs of being a planet. Is this simply a bad seeing? Or could the collimation requirements be so high that im not able to use my "out of focus star"-test and laser collimator to get it right?

I finally got a bunch of new Eyepieces, Meade HD-60 25/9/4.5mm. They have a twisting function, but are not "zoom" so i suspect this is focus. The manual doesn't say anything about it though. Should i use the focusing on the eye piece or on the focuser on the scope?

I am collimating my 10" dobsonian flextube with a laser collimator, but in not really sure how exact i need to bee. I can easily center the laser on the middle dot on the main mirror, and then center it on the "bulls-eye" on the collimator. But there is enough "slopp" in the mechanism/telescope/collimator that the collimation changes slightly every time i put the collimator in the eyepiece holder. It also changes slightly when i change elivation, probably due to too much play in the eyepiece holder. Slightest push on the collimato changes the laser spot. It also changes slightly if i rotate it. The laser is still within the smalles circle, but is it enough? How much off can the laser be on the bulle-eye, before the view is not longer usefull?

I found this advice helpful, "dont buy a premium eye piece for a fast dobsonian(<f5)" in regards to the coma problem, and also field curvature. https://youtu.be/GM76JAzhKgU Also, i found this document, recomending owners of fast dobsonians to upgrade to 60 degree eye piece, like the Celestron X-Cel LX or the Meade HD60. People is generally happy with them from what i have understod. They are also in good supply in the Nordic countries. https://www.acaoh.org/_meetings/2016/2016-02-26_Eyepiece Handout.pdf

That zoom eyepiece looks nice, but due to the Corona situation they are all out of stock at the dealers here. I really wanted to change the stock ones as some people said i would probably be disappointed with the scope otherwise, but i will give it a try.

Mine is a f/4.8 so i probably should avoid the Hyperions, quite a few reviewers had the same issue that you mentioned. Celestron Luminos seams to have the same or very similary issues, is finding good eyepieces for f/5 dobs simply a bit difficult? https://lovethenightsky.com/celestron-luminos-review/ Is it perhaps so that, the problems that both Hyperions and Luminos has, is simply something i half to live with if im not to buy even more expensive eyepieces? And is the quality better in these ones, than the ones that the scope came with? Reading and evaluating eyepiece reviews online as a beginner isn't the easiest thing, its hard to tell what the reviewers consider a good epyepiece, what they compare it too and what expectations they had.

Thanx for the input! I will try to replace at them both with higher quality ones. The dealers in my area are pretty much out of stock, but i they have a few that is within my price range, about 150-200$/piece(prices are often higher in Scandinavian countries). I found Celestron Luminos and Baader-Plantetarium Hyperion, are they any good?

My new 10" f/5 dobsonian came with two eyepieces, 10mm and 26mm. I read on a few different places that these eyepieces arent the best, so i thought i would swap them out directly and buy better ones. My guess is that the ones that came with the scope are 50degree, and that i would benefit from eyepieces with wider field of view. Should i get new ones that are 2" or 1.25"? Are there any designs or brands that i should go for? Sky watcher sells eyepieces that are Plössle Ultra Wide, with 66degrees fov, could that be something to go for, or are there better brands?

The trolley sounds like a good idea! I am really excited to get my new scope, it will probably be a lot better than my diy 130mm "dob". The new one has a real spotting scope, instead of the red-dot one i have now(never had much luck with that).

I finally found one! A dealer i found had a 10" Skywatcher Flextube 250px, basicly the last telescope they had left Now i just halfto wait for it to arrive some time next week. If i could have picked any one of the Dobsinan scopes i would probably have gone for the 8" rigid-tube, will the 10" flex-tube be a big hassle for a beginner?(collimation perhaps is a skilled you need to learn quickly).

Hello! I have had a warehouse type telescope for a couple of years, and used it a lot. This year i saved up some money and had planned to buy a 8" Sky watcher Dobsonian, but to my big disapointment, none of the scandinavian dealers has got any telescopes at all, they are all out! The ones i spoke to said i might get a 8 or 10" dobsonian by the month of june. Its a long wait... Is there situation as bad everywhere?