I got up at 0400 this morning to spend some more time with the gas giants, Jupiter and Saturn. Ok, maybe a little peak at Orion as well. I normally don't post observing reports, but this might be useful info for all the new owners out there that may be disappointed with their first look at these wonders.
Here are some images of what I have seen with my XT10:
http://tinyurl.com/rywb
This morning, seeing was as poor as I have seen it. The jet stream has made its trek down into my area where it will spend most of the next 5 months or so. This really effects my seeing conditions the most in the colder months. So I spent most of the morning looking at the poor images on that page. But there were moments when the
seeing would improve to a 4 or so and I got to see the GRS and more bands. By moments, I mean out of the hour that I dedicated solely to Jupiter, I had less than 1 minute of better seeing. Most of the time I could just make out the 2 equatorial bands, but there were moments when I couldn't even see those. Oh my, that's bad!
So why is this all important? Well, for those going out for the first time with their brand spankin' new telescopes, I wanted to make sure you had realistic expectations. I hope you see my 8 of 10 images. But if you don't, realize that it may not be the telescope. Perfect collimation, mag 7 skies and a $750 eyepiece
cannot overcome the effects of the atmosphere on the image you see.
If you see my poor images, defocus on the image and see if you can see the turbulence. You can use a star or planet for this, just defocus a lot until there is a very large white disc in the eyepiece. If the turbulence is relatively fast, that's atmospheric turbulence. If it is very slow and disorganized, then that's probably in your tube.
I will add that collimation is critical as well on faster dobs (f/5 or f/4.7). My session started with a very poor image that I attributed to poor seeing, but something didn't seem right. Even during moments of better seeing, the image was soft. Also, focus was more difficult than usual to locate. So I checked my collimation. The return shadow of the barlowed laser was off by about 1.5mm (not a lot, but enough). I turned 2 collimation knobs about 1/50th of a turn each and all was good. The image, during
moments of better seeing, had more detail and focus was more snappy. Not to scare anyone, but it matters. Luckily, it's also very easy.
So, I hope this helps the new scope owners and maybe others as well. As always, I would expect a lively exchange on this forum.
Clear skies,
Tom
Here are some images of what I have seen with my XT10:
http://tinyurl.com/rywb
This morning, seeing was as poor as I have seen it. The jet stream has made its trek down into my area where it will spend most of the next 5 months or so. This really effects my seeing conditions the most in the colder months. So I spent most of the morning looking at the poor images on that page. But there were moments when the
seeing would improve to a 4 or so and I got to see the GRS and more bands. By moments, I mean out of the hour that I dedicated solely to Jupiter, I had less than 1 minute of better seeing. Most of the time I could just make out the 2 equatorial bands, but there were moments when I couldn't even see those. Oh my, that's bad!
So why is this all important? Well, for those going out for the first time with their brand spankin' new telescopes, I wanted to make sure you had realistic expectations. I hope you see my 8 of 10 images. But if you don't, realize that it may not be the telescope. Perfect collimation, mag 7 skies and a $750 eyepiece
cannot overcome the effects of the atmosphere on the image you see.
If you see my poor images, defocus on the image and see if you can see the turbulence. You can use a star or planet for this, just defocus a lot until there is a very large white disc in the eyepiece. If the turbulence is relatively fast, that's atmospheric turbulence. If it is very slow and disorganized, then that's probably in your tube.
I will add that collimation is critical as well on faster dobs (f/5 or f/4.7). My session started with a very poor image that I attributed to poor seeing, but something didn't seem right. Even during moments of better seeing, the image was soft. Also, focus was more difficult than usual to locate. So I checked my collimation. The return shadow of the barlowed laser was off by about 1.5mm (not a lot, but enough). I turned 2 collimation knobs about 1/50th of a turn each and all was good. The image, during
moments of better seeing, had more detail and focus was more snappy. Not to scare anyone, but it matters. Luckily, it's also very easy.
So, I hope this helps the new scope owners and maybe others as well. As always, I would expect a lively exchange on this forum.
Clear skies,
Tom
