erick
14-08-2007, 02:59 PM
...getting the scope out??
After what has seemed to be ages of overcast and rainy weather in Melbourne, last Sunday held promise.
That's it, I told my wife, I'm going out tonight! (Well actually it was a "pretty please" request, but she approved).
Of course, by the time I packed up and started driving to an observing spot, the clouds came over and some rain fell!
Still I set up and collimated before sunset, enduring a few spots of rain. Cloud never reduced to less than 50% of the sky. By about 9:30 it became fully clouded and fog descended. I got about 40-50 minutes observing through clear (clearish?) sky, all up.
However I was able to:-
* before sunset, try out my webcam for infinity focus. I previously couldn't get enough infocus, so I had chopped some length off the adapter (and the webcam threaded tube) allowing the adapter to screw further into the webcam. OK, I could focus on trees on the hilltop some 4-5 km away and still had a mm or two to go. I think that will be OK. I'll try again from my backyard when I have power for the lappy and some stars and Jupiter to point at.
* finally had a look at alpha Crucis and split the double for the first time (yes it's been 5 months I've had the scope and haven't done this before now! Slack?)
* tried my new 2" DGM Optics NPB filter on Carina. I'd been testing out this brand of filter, using a borrowed 1.25", so was restricted to 15mm EP. Now I was able to use a 30mm and a 26mm. I thought: WOW! That's superb. The nebula really jumped out against the darkened sky. I'm going to enjoy this filter.
* spent a bit more time with my new (secondhand) Vixen LVs - 10mm and 6mm. I'm liking these more and more. 2x barlowed up on Jupiter was nice. What I really notice is the eye relief. With my eye off the rubber cup (my preferred way of viewing), the edge of field was easily seen. Going back to
my 9mm plossl, I realised that I've always been struggling to see the edge of field (the field stop, I should say?) unless I push my eye very close to the lens. Later I dived deep into the guts of omega Centauri with the 6mm and felt I was swimming in all those stars which were completely filling the FOV - lovely!
* spent more time with my Chinese 2" 30mm 80 deg AFOV ultrawide (ex Bintel). Getting to feel comfortable with this EP as well. When I compared with my 26mm and 40mm Kellners (from Bintel), I preferred the 30mm. Yes, only the centre 50% (approx. linear measurement) of the view was sharp (8" f6 reflector), but I didn't pay many dollars, did I. If I focus on the Jewel Box, then place it at the edge of field, I could still recognise it. I think I can live with that. Eye placement was very sensitive. Again, the best spot for me was holding my head with eye not touching the rubber cup, as I preferred. I could find a location where I could see the entire FOV, but it took some eye movement to see all round the 80 deg! Moved my head out, I lost the full field, but centre remained sharp. Moved my head in and parts of the field started blacking out (don't know the right terminology, sorry). I did try the suggested addition of a Barlow (whole barlow, or just screwing the barlow lens into the EP. In both cases, the edges of the field were substantially more out of focus, so that option doesn't work for me and this EP.
So, all in all, it was not a waste of time at all. I studied several other familiar objects briefly, sat back during times when the cloud rolled in and listened to the radio. Peaceful and feelin' just fine!
Thanks for reading
Eric. :)
After what has seemed to be ages of overcast and rainy weather in Melbourne, last Sunday held promise.
That's it, I told my wife, I'm going out tonight! (Well actually it was a "pretty please" request, but she approved).
Of course, by the time I packed up and started driving to an observing spot, the clouds came over and some rain fell!
Still I set up and collimated before sunset, enduring a few spots of rain. Cloud never reduced to less than 50% of the sky. By about 9:30 it became fully clouded and fog descended. I got about 40-50 minutes observing through clear (clearish?) sky, all up.
However I was able to:-
* before sunset, try out my webcam for infinity focus. I previously couldn't get enough infocus, so I had chopped some length off the adapter (and the webcam threaded tube) allowing the adapter to screw further into the webcam. OK, I could focus on trees on the hilltop some 4-5 km away and still had a mm or two to go. I think that will be OK. I'll try again from my backyard when I have power for the lappy and some stars and Jupiter to point at.
* finally had a look at alpha Crucis and split the double for the first time (yes it's been 5 months I've had the scope and haven't done this before now! Slack?)
* tried my new 2" DGM Optics NPB filter on Carina. I'd been testing out this brand of filter, using a borrowed 1.25", so was restricted to 15mm EP. Now I was able to use a 30mm and a 26mm. I thought: WOW! That's superb. The nebula really jumped out against the darkened sky. I'm going to enjoy this filter.
* spent a bit more time with my new (secondhand) Vixen LVs - 10mm and 6mm. I'm liking these more and more. 2x barlowed up on Jupiter was nice. What I really notice is the eye relief. With my eye off the rubber cup (my preferred way of viewing), the edge of field was easily seen. Going back to
my 9mm plossl, I realised that I've always been struggling to see the edge of field (the field stop, I should say?) unless I push my eye very close to the lens. Later I dived deep into the guts of omega Centauri with the 6mm and felt I was swimming in all those stars which were completely filling the FOV - lovely!
* spent more time with my Chinese 2" 30mm 80 deg AFOV ultrawide (ex Bintel). Getting to feel comfortable with this EP as well. When I compared with my 26mm and 40mm Kellners (from Bintel), I preferred the 30mm. Yes, only the centre 50% (approx. linear measurement) of the view was sharp (8" f6 reflector), but I didn't pay many dollars, did I. If I focus on the Jewel Box, then place it at the edge of field, I could still recognise it. I think I can live with that. Eye placement was very sensitive. Again, the best spot for me was holding my head with eye not touching the rubber cup, as I preferred. I could find a location where I could see the entire FOV, but it took some eye movement to see all round the 80 deg! Moved my head out, I lost the full field, but centre remained sharp. Moved my head in and parts of the field started blacking out (don't know the right terminology, sorry). I did try the suggested addition of a Barlow (whole barlow, or just screwing the barlow lens into the EP. In both cases, the edges of the field were substantially more out of focus, so that option doesn't work for me and this EP.
So, all in all, it was not a waste of time at all. I studied several other familiar objects briefly, sat back during times when the cloud rolled in and listened to the radio. Peaceful and feelin' just fine!
Thanks for reading
Eric. :)