Saturn series, Feb 15th, and dark spot

Paul Delligatti · #1 23-02-2011, 05:47 AM

Hi Folks,

Seeing was decent for a change. f25, 8" SCT

1) 1035UT was shot near meridian, 1/30, 30fps
My capture duration was 90 seconds. But, freezes, dropped frames caused a loss of 75% of my potential frames. About 700 frames. The rest were shot at 1/19, 15fps, 90 seconds with only about 10% dropped frames. Approx 3000 frames.
2) 1100UT
3) 1120UT
4) 1138UT
5) 1144UT

Sorry my resolution is not that great. But, storm trails are visible and the dark spot can be made out a little bit among those trails.
Hopefully, I can get things in my setup fined tuned in my image train and go to f30. Thanks for looking.

iceman (Mike) · #2 23-02-2011, 06:05 AM

Nice work Paul, well done.

renormalised (Carl) · #3 23-02-2011, 12:24 PM

Nice shots, Paul

The extra FL will help once you've got things running smoothly.

Need a x5 Powermate

John Hothersall · #4 23-02-2011, 05:50 PM

Great work Paul, glad you put these up. The 4th and 5th are the best with the storm showing quite well at this FL. If seeing allow you may go to a longer FL.

John.

Matt Wastell (Matt) · #5 23-02-2011, 07:52 PM

Great storm captures Paul - a very nice record of the event!

Paul Delligatti · #6 24-02-2011, 03:39 AM

Thanks for looking. Maybe you all could give me some tips to increase FL?

I have been trying to increase FL and go to f30. But, I don't have a 3x barlow. I put the 2x Big Barlow into telescope back, followed by a Televue Everbright Dialectric diagonal, which gets me to about f30.
I realize many imagers don't use a diagonal. Astronomer and owner of Starizona (maker of Hyperion Astrograph), Dean says with this quality diagonal, there should be no perceptable degradation or other aberrations. Scott, who is a planetary imager and works there, agreed.

BUT, no matter how I try, the image is too dim. The histograms in all channels fail to reach desirable curves that I associate with good images at f25, even under good seeing. (IC Capture) If I max out gain, it is still too dim. If I increase gamma above 100, the stacked images have a bad diagonal lines in a pattern across the image.

This is what I have considered so far:

1. Try another capture program.
2. Dump diagonal for high quality 3x barlow (if it exists.)
3. Dump diagonal for an extension tube attached to 2x barlow.
4. Consider that for this scope (Ultima 2000 SCT, good optics,
poor coatings) will only be useful for DSO imaging at f2 with
Hyperstar and save for a 11 to 14 inch SCT. (Edge HD?)
5. Be content with f25.

The other thing, my jpeg's for posting don't look as good as my tif's.
But, this is common from what others have said. But, I am still developing a solid processing routine, using tools like deconvolution,
unmasking, sharpening, for example.

Thanks again.

Paul

Clayton · #7 24-02-2011, 07:30 AM

Quote:

Originally Posted by Paul Delligatti

Thanks for looking. Maybe you all could give me some tips to increase FL?

I have been trying to increase FL and go to f30. But, I don't have a 3x barlow. I put the 2x Big Barlow into telescope back, followed by a Televue Everbright Dialectric diagonal, which gets me to about f30.
I realize many imagers don't use a diagonal. Astronomer and owner of Starizona (maker of Hyperion Astrograph), Dean says with this quality diagonal, there should be no perceptable degradation or other aberrations. Scott, who is a planetary imager and works there, agreed.

BUT, no matter how I try, the image is too dim. The histograms in all channels fail to reach desirable curves that I associate with good images at f25, even under good seeing. (IC Capture) If I max out gain, it is still too dim. If I increase gamma above 100, the stacked images have a bad diagonal lines in a pattern across the image.

This is what I have considered so far:

1. Try another capture program.
2. Dump diagonal for high quality 3x barlow (if it exists.)
3. Dump diagonal for an extension tube attached to 2x barlow.
4. Consider that for this scope (Ultima 2000 SCT, good optics,
poor coatings) will only be useful for DSO imaging at f2 with
Hyperstar and save for a 11 to 14 inch SCT. (Edge HD?)
5. Be content with f25.

Thanks again.

Paul

I would stick with f25 unless the seeing is exceptional. If you wish to go to f30 you can compromise a fair bit on a full histogram with Saturn (thanks for the tip Asimov) You might also push the gain a bit harder and capture for a bit longer (90sec is a bit short IMHO) to combat the noise.
I am a bit confused about 15fps X 90sec = 3000 frames

Nice shots BTW

samilag (Giuseppe) · #8 24-02-2011, 08:17 AM

Nice images Paul, nice images with this seeing, I think you can get more with better seeing

Giuseppe

Paul Delligatti · #9 24-02-2011, 09:47 AM

Thanks Clayton.

I sure hope I have f30 worked out and good seeing in April!

Sorry for the confusion.

3 channels RGB, 1350 frames per channel, pared down to 1000 frames per channel, for the final 3000 frames. Registax is like weeding a garden...to a degree. I'm using Orion filters. But lookin' at something better for April.

Paul

Quark (Trevor) · #10 24-02-2011, 12:13 PM

Hi Paul,

For the equipment that your using I think these are creditable results.

Have you ever considered a ToUcam, they are still around and have a very good track record. Many of todays top planetary imagers cut their teeth on ToUcams.

Cheers
Trevor

Paul Delligatti · #11 24-02-2011, 03:45 PM

Thanks Trevor.

When I got the Ultima 2000, my intention was something portable for observing, and easy to use. Never really considered imaging. Started playing with a NexImage solar system camera for fun a couple years ago. Decided to plunge deeper. It is nice for a novice to have some realistic assessment from the experienced imagers who know which equipment works well for a specific application, and importantly its limitations. I had no previous benchmarks and don't want to be unrealistic.