OneOfOne
22-08-2006, 08:15 AM
I didn't get a lot of time to view last night, we were clouded over by just after 9:00 and I didn't finally get set up until nearly 8:00. Anyway, I swung the scope around to Eta Car first (I was actually testing my new UHC filter) and put in the 10. The whole area basically filled the view, the neighbours spotlight made viewing pretty hard though. I noted the sharpness, what detail I could see etc. and then swapped over to the 30. The first impression was how bright the background sky became compared to the 10, to be expected though as the sky was quite bright anyway (I could only see three stars in Crux). The whole of Eta Car was contained to a small area in the centre of view. Another thing I found is the amount I had to move the focusser out, pretty much to the limit. I may have to look at a spacer of some sort to try to make it a little more parfocal with the 1 1/4's. The second biggest surprise was the sharpness of the image. I was expecting, with a magnification of 33x and FOV of about 2 degrees, to get some noticable dropping off in sharpness toward the edge...but it was as sharp near the edge as the 10! Now that is impressive.
Next I tried the Butterfly Cluster, this is big enough to completely fill the FOV of the 10. Put in the 30, the cluster was tack sharp in the middle. Unfortunately, there weren't enough stars to fill the whole view. I moved the cluster to one edge of the view and then over to the next one, watching the focus as it traversed from side to side. Even with the cluster touching the edge of the field, I could not discern any appreciable falloff in quality. If I was to focus on the cluster when it was on the edge, I don't know if I would bother to change it compared to the centre....if I didn't know it was the 30, I could convince myself I was looking through the 10 with the quality I could see.
In summary:
Such a low magnification will brighten the sky a LOT. Investing in a 2" UHC filter maybe a worthwhile investment.
The out travel may require a spacer to allow you to swap to a 1 1/4" without having to wind it in and out so much.
Although, I didn't get a chance to view much, my first impression of the sharpness and focus across the field is "impressive".
The eyepiece is heavy, so if you have a dob, you may need a counterweight of some sort when you put it in.
I need to find a cluster that spans up to 100 or so arc minutes so I can fill the view with stars all at once to be able to better judge the overall "quality" of the field.
Unfotunately, Melbourne is supposed to be clouded over until Saturday...fingers crossed!
Next I tried the Butterfly Cluster, this is big enough to completely fill the FOV of the 10. Put in the 30, the cluster was tack sharp in the middle. Unfortunately, there weren't enough stars to fill the whole view. I moved the cluster to one edge of the view and then over to the next one, watching the focus as it traversed from side to side. Even with the cluster touching the edge of the field, I could not discern any appreciable falloff in quality. If I was to focus on the cluster when it was on the edge, I don't know if I would bother to change it compared to the centre....if I didn't know it was the 30, I could convince myself I was looking through the 10 with the quality I could see.
In summary:
Such a low magnification will brighten the sky a LOT. Investing in a 2" UHC filter maybe a worthwhile investment.
The out travel may require a spacer to allow you to swap to a 1 1/4" without having to wind it in and out so much.
Although, I didn't get a chance to view much, my first impression of the sharpness and focus across the field is "impressive".
The eyepiece is heavy, so if you have a dob, you may need a counterweight of some sort when you put it in.
I need to find a cluster that spans up to 100 or so arc minutes so I can fill the view with stars all at once to be able to better judge the overall "quality" of the field.
Unfotunately, Melbourne is supposed to be clouded over until Saturday...fingers crossed!