Posts Made By: Lou Roque

Hi, Can anyone tell me what would be the faintest star magnitude that I could see with a 6", 8", 10" or 12" dob telescope under lets say perfect conditions? I just want to get an idea of what to expect. I am new to astronomy and will be purchasing a serious telescope for the first time this year.
Thanks.

I'm deciding on a 32mm or 26mm eyepiece. One gives me an exit pupil of 5.5mm, the bigger one an exit pupil of 6.8. Do you think I'd be wasting light with the 6.8mm exit pupil, since I'm 63 years old?

I collimated my Orion XT10 with the collimation cap that comes with it and then checked the collimation with a laser collimator that I purchased with the scope (both items used). There seems be over an inch difference between them. I'm just wondering if this is due to the slop in the 2" focuser and 1.25" adapter, when I put in the laser collimator or eyepieces in? I tried turning the laser in the focuser and the dot did not vary to much. How critical is collimation? I haven't had a chance to look at the sky with the scope yet, because of the weather.

Thanks, for the information. I'll keep it all until I can understand it all better. Right now it seems to look to me as if, I were to purchase a 10" dob instead of a 5" dob and all other things being the same, the max magnitude would go up about one, increasing power from maybe 100x to 200x will on the same telescope, give me a jump of about 2 mag. I thought that there would be a larger increase in max magnitude if I went from a 5 incher to a 10. I'll keep studing it closer in the next week.
Thanks again, Lou.

I also forgot to mention that the 32mm is a 2" eyepiece and the 26mm is 1 1/4". I don't know if it matters.

I looked up at Mars today about 10pm and it looked whiter than usual. I looked at it through my XT10 and it just looked like a bright star, no detail. White. Is this due to our atmosphere or is it those Martian dust storms? A week or so ago it looked more orange.