clear sky chart

Job 9:9

Job 9:9-10
9 He is the Maker of the Bear and Orion,
the Pleiades and the constellations of the south.
10 He performs wonders that cannot be fathomed,
miracles that cannot be counted.

Wednesday, August 29, 2012

This morning's Jupiter

Seeing was EXCELLENT this morning.  Got some fine detail, and I had time to experiment with the camera settings.

My best image of the evening, in my opinion:
This one was resized in Registax 150%.  I was using the 6: f/5 C6NGT and a Logitech Quickcam 4000.  Consists of 1200 frames at 10 fps stacked in Registax 6.

This next frame was taken at 320X240 using the same equipment, except the frame rate was set to 30 fps.  This one has about 3000 frames.

One more 10 fps 640X480

One thing I was experimenting with was the brightness of the images in the camera.  Being most webcams are 8 bit, I found that if the brightness is set so the histogram is set to 250 - 255 (as bright as you can get without over exposing), the better the image will be.  The last image, the histogram only was around 200, and you can see the eggshell effect.

The black spot is the shadow of the moon Io, which is the closest moon on the left.  The other moon is Europa.  I actually just missed a double shadow transit that began about 10 minutes after I finished imaging.  It was starting to get light out, and the seeing started to deteriorate, so I packed it in.

Sunday, August 26, 2012

Marathon Imaging Session 8/25 -8/26

Nice clear nights with slightly more than a first quarter moon, and its a Saturday night and I was feeling pretty good, so I thought I'd image a few things that I havent yet.

The evening started out with the moon.  Using the webcam and a 3X barlow on the 6", I managed to capture these:

Not a bad night, seeing wise.  Very little turbulence and the moon, this time of year is not very high in the sky.

After capturing these, I went over to the Iris Nebula inCepheus.  Although I was able to capture enough subs, the finished product is not great, partly because the moon was still above the horizon.  This is what I ended up with

From there, I recharged the laptop and went to the Bubble Nebula in Casseopia.  This one came out pretty good actually, especially for my light polluted sky.  By now, the moon had set.

I let this run for 50 2 min frames and went to bed.  Set the alarm for 2 hours, got up and imaged Jupiter.  It came out so bad, that I'd be embarassed to post it.  From there, I took in a couple big galaxies.  The first being M33.  Trouble is, the battery in my mount was dying, so it didnt track well.  I shot 30 subs, but only 5 were useable.  This is what it looked like
Then I thought I'd shoot the granddaddy of them all - Andromeda.  Of course, its so big I cant fit it in the field of view of the telescope.  I got the central part.

>Total imaging time for everything you see here? About 9 hours.

Saturday, August 25, 2012

The Cocoon Nebula

This image was actually taken on 8/18/12.  I have been working on this image a few times, and although previous attempts were not bad, I have been struggling with amp glow with the Canon 300D.

Today, I took 25 bias frames.  These are similar to dark frames - the lens cover is on, and the shutter speed set to 1/4000 second.  The idea is to measure the pixel bias and subtract that bias from the flats, darks and lights.  When I used the bias frames, the amplifier glow vanished!  This made the image much easier to process and got rid of some nasty gradients on the right side of the image.  I will have to try this out on the 1100D also, as I have some really bad gradients on it that I havent been able to process out.  This might be the missing link.  Although it did not remove ALL of the amp glow, it did remove most of it.

Here is the final image of the Cocoon Nebula (IC 5146, Caldwell 19).

The Cocoon Nebula lies at the end of Barnard 168, a dark nebula, which is visible in this image as the area above the red Cocoon that is mostly absent of stars.  If you also look closely, there is some dim blueish nebulocity on the edge of the red, on the bottom right part of the Cocoon in this image.  Although not as prominent in the Cocoon as in the Trifid, all 3 types of nebulocity exist in this object.

Thursday, August 9, 2012

The Witches Broom NGC6960

After several attempts of having mediocre luck capturing the Witches Broom, I decided to attempt it once again from a darker location.  Not a  REAL dark spot, but better than it is from home, I took the telescope to my place of work, which has 2 high pressure sodium lights in the front parking lot.  I have photographed successfully from the grass behind the building, so the buildings block the light from the parking lot lights.  It was well worth the trouble, as I was also able to get a fair image of the Milky Way near Cygnus.  I imaged this Monday night (8/6/12).

I used my version of the LLRGB technique that has been described in various email groups.  This is basically how I did it.

I cropped the image as I brought it into photoshop.  Copied the image to a new image, set the 2nd one to black and white.  Did levels and curves to bring up the brightness and contrast.  Did 2 iterations of "Local Contrast Enhancement.  Did an unsharp mask.  From there, reduced the star size several times.  Did some fine curves adjustment to reduce any background gradient that existed without dimming the DSO.  Did a "Less Crunchy, More Fuzzy" filter.

Went to the color copy, did levels and curves.  Went to exposure and increased the offset by about 100.  This brings the dark point well above 0.  From there, I enhanced the color using lab color curves.  Once the color was the way I liked it, I changed it back to RGB.  From there, I used levels to bring the black point to about 30 - 40 at the darkest section of sky.  I do this so any changes in color or star reduction or contrast enhancement does not clip the black level.  I did 1 contrast enhance, reduced star size a couple times, then I did 2 iterations of "Less Crunchy, More Fuzzy".  Then I did some curves, adjusting each RGB channel to line up the histogram colors.  Adjusted the master curves to take out background noise.  Blurred the image a couple pixels.

Then I went back to the monochrome version, I copied the entire image, pasted it on top of the color image, and set the new layer it created as a luminance layer.  Did another slight curves adjustment after flattening the image.  Did a "less Crunchy, More Fuzzy".  Then reduced stars, and another "Less Crunchy, More Fuzzy".

That was the basic workflow.  When I use the synthetic luminance method, I do not try to get every wee little bit of nebulosity out of the image, but instead, I strive to increase the detail, and bring out as much of the nebulosity but try to keep the "clean" look, with lots of color and such.

This is the same image, using the same subs, but uncropped, without the synthetic luminance.

Can you tell a difference?  I can, and with careful processing and noise control of the false luminance layer, one can get a nice clean image with enhanced detail, less noise and deeper color and more of the faint nebulosity.