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As some of you know, I postponed the purchase of a Dobson for a few good years. Now that things in life are a bit more stable, I am in the market for this Dobson.
It will take a bit before I press the button, as I still need to understand a few things about dobsonians.
I've been contemplating a classic truss 12"-12.5" f5.5-6 for a while, as this would offer me a trade-off among portability, focal length, power, DSO, planetary, no coma corrector, and standup observing.
Mirror and mount are equally important to me. I haven't yet decided, but I'm leaning towards an Astrosystems or Teeter 12.5" f5.5-6.
Yes, customs and shipping won't be cheap. It's a telescope to last though.
Any thought is welcome of course.
Hello guys,my 8" dob is arriving soon.
I have trouble setting my expectations
Since i have looked through my 3 " dob its hard picturing what i could see with an 8" one.i live in a light polluted city.
Can i look at any dsos directly?
How will they look like using adverted vision?
What can i expect to see?
Also which all around filter should i buy (2") to look at dsos and maybe some planets?
By David Smith
I've been considering a short focal length frac to get solar full disk images for a while now and when one came up on ABS the other week I took the plunge and picked up a Bresser AR102xs. It's focal length meant that I could potentially get a solar full disk with my ASI178 in one frame, great for grabbing a disk quick when the weather's not so great (when isn't it). I've also got half an eye on an upgrade to my H Alpha setup which might include a Quark bolted to a short focus frac, so this fits the bill again.
I managed a quick and dirty first light the day after I collected it but didn't really draw any conclusions due to the rushed nature of the session. Today I had a longer session and managed to explore both white light and Ca-K with this scope. After that initial look with the scope I did not think I could get focus with the Herschel wedge but I managed fine today! It is kind of tough to judge the results with no detail to be seen though.
The Ca-k is more worrying to be honest, the concern with Ca-K is spherical aberration which limits sharpness in the final image and results here don't look great to me. The advantage of doing a full disk in one shot is that I can combine surface and prom layers like this.
Not sure if I am just expecting too much from the little scope after being spoilt by my Evostar 120 for so long, or whether there is actually an issue. Jury's out until I get a session in with a nice AR to look at and in the meatime I wil try some night-time wide field viewing.
After adding several large two-inch eyepieces and an Explore Scientific illuminated finder scope, my dob was quite top heavy. To remedy this, I added two 18” bar magnets to the bottom portion of the scope. Balance now seems nearly perfect! Got this idea from another post I read a while back on SGL!
I have a GSO 6" f/4 Astrograph, and there's always been this issue with elongated stars on one edge. I've checked collimation and it is perfect, but for the elongation on one corner. Could someone please throw some light on what's happening