M57 last night
Jun 17, 2020 19:49:31 #
Ballard
Loc: Grass Valley, California
Last night I took a bunch of 3 minute subs of the ring nebula and here is the result. This was taken at 4000mm and cropped to enlarge the nebula. The seeing wasn't all that good last night and about 80% of the 50 subs where useable, the rest had the stars too bloated as the atmosphere became very turbulent after midnight. These where taken at ISO 800 on my DSLR at F10 through the meade 16 inch. The spiral galaxy IC 1296 is visible above the nebula at magnitude 14.3. When I stretched the image a lot I could see a faint halo around the nebula somewhat thicker than the ring itself, when stretched that far the noise looked pretty bad and the ring was completely blow out (see second image below) a lot more stars are also visible but they tend to blot more also.All comments, suggestions and questions are welcome.
Jun 17, 2020 20:24:36 #
Pretty!
The Ring Nebula is another of my favorites.
When I was starting out, I imaged it with my DSLR. But through my pea-shooter 480 mm telescope it looked like a speck.
If I hadn't have known what to look for I would never have spotted it. LOL!
I get better shots with my current camera, but I can only dream what a trial it would be to get out there at 4000 mm!
The Ring Nebula is another of my favorites.
When I was starting out, I imaged it with my DSLR. But through my pea-shooter 480 mm telescope it looked like a speck.
If I hadn't have known what to look for I would never have spotted it. LOL!
I get better shots with my current camera, but I can only dream what a trial it would be to get out there at 4000 mm!
Jun 17, 2020 20:34:44 #
Ballard
Loc: Grass Valley, California
SonnyE wrote:
Pretty!
The Ring Nebula is another of my favorites.
When I was starting out, I imaged it with my DSLR. But through my pea-shooter 480 mm telescope it looked like a speck.
If I hadn't have known what to look for I would never have spotted it. LOL!
I get better shots with my current camera, but I can only dream what a trial it would be to get out there at 4000 mm!
The Ring Nebula is another of my favorites.
When I was starting out, I imaged it with my DSLR. But through my pea-shooter 480 mm telescope it looked like a speck.
If I hadn't have known what to look for I would never have spotted it. LOL!
I get better shots with my current camera, but I can only dream what a trial it would be to get out there at 4000 mm!
Hi Sonny
The guiding has to be bang on at 4000mm and the sky turbulence becomes a bigger factor also. The sky last night was starting to get a bit choppy and I didn't get as many usable subs as normal but still enough to get a decent shot of M57. The DSLR works, but it is pretty much blind to the HA lines and one of these days I'll switch to a real astro camera to hopefully improve the images I'm able to get.
Jun 18, 2020 12:18:13 #
Ballard wrote:
Last night I took a bunch of 3 minute subs of the ... (show quote)
Nice, anytime I can see the central star and some of the outer ring I consider it well done. The stretching really brought out the galaxy.
You definitely need focal length to get a proper image scale, which I found out using the Hyperstar on a C11. It makes it about 588mm and the Ring is waaaay to small.
Jun 18, 2020 12:38:34 #
Ballard
Loc: Grass Valley, California
Hi Alberio
The image scale at 4000mm is good for planetary nebula and a lot of galaxies. I find that for planets it is better to use a 2X to 3X barlow to increase the focal length further. It is too long for large objects and the APO and telephoto lens are much better for those objects. As I get better at this I might try to stitch multiple images together of some of these larger objects to make a really high resolution image taken at 4000mm.
The stretch brought out IC 1296 but the noise really came out and the stars tended to blot a lot (pushing the DSLR a bit much). The dim outer layer of the nebula came out but it is mainly bright in the HA lines that the DSLR tends to filter out. It is interesting that the HA comes out with a green to aqua tint on what HA does get recorded but this is probably an artifact of the bayer pattern that has 2 green pixels for each red and blue pixel. One of these days I will get a monochrome camera and a filter wheel.
The image scale at 4000mm is good for planetary nebula and a lot of galaxies. I find that for planets it is better to use a 2X to 3X barlow to increase the focal length further. It is too long for large objects and the APO and telephoto lens are much better for those objects. As I get better at this I might try to stitch multiple images together of some of these larger objects to make a really high resolution image taken at 4000mm.
The stretch brought out IC 1296 but the noise really came out and the stars tended to blot a lot (pushing the DSLR a bit much). The dim outer layer of the nebula came out but it is mainly bright in the HA lines that the DSLR tends to filter out. It is interesting that the HA comes out with a green to aqua tint on what HA does get recorded but this is probably an artifact of the bayer pattern that has 2 green pixels for each red and blue pixel. One of these days I will get a monochrome camera and a filter wheel.
Jun 18, 2020 13:39:22 #
One of these days I will get a monochrome camera and a filter wheel.
Don't do it, I like the skies cloud free. 🙂🙂🙂
Don't do it, I like the skies cloud free. 🙂🙂🙂
Jun 18, 2020 18:04:21 #
alberio wrote:
One of these days I will get a monochrome camera and a filter wheel.
Don't do it, I like the skies cloud free. 🙂🙂🙂
Don't do it, I like the skies cloud free. 🙂🙂🙂
When I bought my mount in February, I snuck it home in the back seat of my truck, snuck it in the house under the cover of clear skies/daylight, and only took it out in the dark.
Then one night about 2 weeks later this itty-bitty cloud appeared. That little blabber-mouth told the rest, and it was crappy weather for over a month! Clouds, rain, and crap!
Finally, they gave up. But man, what punishment!
All I want is a 5" refractor, and a ASI1600 MM Pro with filter wheel, and to double stack.
But the people in hell have a better chance of getting ice water, than I do of more toys.
Jun 18, 2020 18:14:41 #
Jun 20, 2020 12:30:46 #
Ballard
Loc: Grass Valley, California
alberio wrote:
One of these days I will get a monochrome camera and a filter wheel.
Don't do it, I like the skies cloud free. 🙂🙂🙂
Don't do it, I like the skies cloud free. 🙂🙂🙂
For the past few days it has been clear in the morning and then a high layer of clouds fill the sky by early evening. Perhaps just contemplating the idea has changed the weather.
Jun 20, 2020 14:26:39 #
That’s a difficult target, and wow at 4000, great guiding. Do you do any planets, that would be nice.
Jun 20, 2020 15:06:32 #
Ballard
Loc: Grass Valley, California
I did some planets at the end of May with barlow in place (~8000mm). They came out OK considering how low in the sky they were (~30 degrees above the horizon). The seeing was mediocre at the time.
https://www.uglyhedgehog.com/t-648341-1.html
https://www.uglyhedgehog.com/t-648341-1.html
Jun 20, 2020 15:34:29 #
Those turned out well. I’m going tp give them a try later this summer. But I don’t have your focal length. I did get an ADC that I haven’t tried out yet.
Jun 20, 2020 17:14:39 #
SonnyE wrote:
I can only dream what a trial it would be to get out there at 4000 mm!
Just imagine aiming Hubble. The focal length is 57,600mm!
Jun 20, 2020 18:30:02 #
Ballard
Loc: Grass Valley, California
Europa wrote:
Those turned out well. I’m going tp give them a try later this summer. But I don’t have your focal length. I did get an ADC that I haven’t tried out yet.
I've never tried an Atmospheric Dispersion Corrector, but it should help on the planets particularly when they are so low in the sky. For the images of planets, I did have to shift to blue and red channels a bit to get them to line up due to the atmospheric dispersion. Mars should be much bigger and higher in the sky for us folks in the northern hemisphere by late September. Jupiter and Saturn will take a few more years before they get in prime position again.
Jun 20, 2020 18:32:54 #
Ballard
Loc: Grass Valley, California
JimH123 wrote:
Just imagine aiming Hubble. The focal length is 57,600mm!
You need a really large sensor to see much sky with that focal length. Those stabilizing Gyro's must be really accurate to hold the image steady for long image sessions.
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