NOPE!

I’ve been socked in for the past 2 months. I’m looking out the window as I write this and it is completely clouded over. The few days that had clear skies where during the weekdays. So that’s not helpful. It was pouring rain during the normal monthly star parties so I didn’t even go.

On the bright side, I took some pretty non astronomy related pictures with my new camera.

Of course it didn’t end there, getting the camera is only the start.  I had to get a good, fast lens to match.  So after yet even more hair pulling, I decided to get the Sigma 30mm f/1.4 lens.  When I took the picture of the Milky way a couple of months ago, I was using a 17mm F/4 lens.  This means that my new lens is 3 full stops faster than the one I used for the previous photo.  That should make a really big difference in the amount of light I could gather.  I could lower the ISO setting to 400 in order to reduce some of the noise in the old picture.

Next outing for the Hawaii Astronomical Society is in 2 weeks.  Until then, I guess I’m going to use to the camera and just take some pictures.m

 I’ve darken the picture a bit because it seems to show more detail.  The picture is definitely kind of crappy.  There are hardly any details visible other than 2 brown bands.  What I need to figure out is whether the poor quality is due to something I did wrong or that I’ve reached the limits of my 6″ scope.  It could be that I didn’t focus the scope as well as I could have.  It is not easy to focus a dobsonian scope with the webcam.  If you play the video, you would notice that Jupiter goes out of frame in about 20 seconds.  So that’s the amount of time I have to adjust my focus before I have to move the telescope.

Other reasons could be the light pollution.  Maybe I could get a better picture if I’m at a dark site.  Also I’m not too sure about the seeing of the night.  The video didn’t show too much bluring so I think the seeing was pretty good that night.

I guess for astrophotography, the ultimate goal is to capture the sky as sharp as possible and with as much detail as possible.  So when I processed the pictures I took from the last star party, I simply tried as hard as I could to bring out as much detail as possible.  However, the more I look at the picture, the more “busy” it looks and everything just looks messy.  When I looked back as some of the constellations pictures at astropix I realized that Jerry had used a diffusion filter on his pictures.  Actually, he said in his tutorial that a fog filter will soften the picture and bring out the bright stars of the constellation better.

I couldn’t really just take another picture with a fog filter so I decided to see if I could simulate the effect in photoshop.  After a lot of trial and error (there are a lot of filters in photoshop, and none of them is labeled diffusion), I found that the effect I was looking for is call the soft focus.  Soft focus is used mostly in portraits to give the subject a softer look.  A softer look reduces the effects of harsh lines and intensifies colors.  To simulate the effect in photoshop (no, there isn’t a soft focus filter like they should have), you have to use the Gaussian blur.  Here is a great tutorial on how to properly use the Gaussian blur in photoshop to simulate a soft filter.

I applied a very strong soft filter to the image I took last star party and here is the result:

Scorpius and Sagittarius with heavy soft focus applied

As you can see, a lot of the background stars have been wiped away.  But this is different than simply turning down the brightness because the bright stars kept their brilliance and is much more pronounce than before.  You can now very easily pick out the major constellations in the picture.  The star’s color shows up much better now that it is not fighting with the background as much.  Overall, I think it looks pretty good.

Usually, about 15-20 club members and about 30 or so general public will show up at the star party.  Most of the telescopes there during a public star party are dobsonians ranging anywhere from 6″ (mines) to 18″ (someone else).  Most of the telescopes last Saturday was on Jupiter as it is very high in the sky at this time of the year and a good target for any size telescope.  However, last Saturday I was on a mission, I was there to take my first, good, picture of the sky.

Most of the club’s members are old school amateur astronomers and do their work visually.  There were only 2 other members doing astrophotography besides myself so I setup my equipment, which amounts to a the canon XTi on a tripod, near them.  One member, Steven, was set up with a 8″ f/4 newtoian on a Vixen sphinx mount.  Some of the pictures he took was pretty amazing.  The other was doing the same thing I was, wide angle fixed tripod astrophotography.  Turns out he was just starting out too.

But enough of that, I was there to take pictures.  So after some camera fiddling I manage to take this picture:

Canon XTi, 17mm focal length, f/4, ISO 1600, 30 seconds exposure

I couldn’t stop smiling when I saw the picture on the camera’s screen.  It was hard for me to believe that I was able to capture so much of the Milky way core in a single 30 seconds exposure with a fairly slow lens.  The picture was pointing South towards Sagittarius; the same view as the picture I took from my balcony.  The difference, of course, is that this is from a pretty dark site.  I was so excited about the success that I completely forgot to take any dark frames or bias frames for later.  I did remember to take several pictures from the same angle for stacking.  Unfortunately a cloud moved in and ruined all but that 1 picture.  I guess I should be happy that at least 1 picture turned out good.

contrast and color adjust of the Milky way core

The picture looks pretty good, the Milky way core has lots of detail.  You can easily pick out M6, M7 and the Lagoon nebular in the picture.  There are also a lot of colors that you could see.  Star trails doesn’t seem to be a problem at this focal length and exposure time.  In case you’re curious, the mountains at the bottom is the Waianae mountain range, 1 of 2 mountain ranges on Oahu.

The person who loaned me the camera had some dark and bias frames from an earlier shoot and he wanted to see what the picture would look like when both are subtracted from the light frame.  He also adjusted color, contrast and ran the image through noise ninja to tone down the noise.

dark frame and bias frame subtracted, color and contrast adjusted, noise ninja'ed

The picture has much better contrast especially at the center of the Milky way.  The red shows up very clear.

I wanted to see at which focal length star trails becomes apparent.  That was harder than I though because I could not see the setting on the lens in the dark and I don’t have a red flash light.  So I guessed at it and took a picture.

Canon XTi, 53mm focal length, f/5.6, ISO 1600, 30 seconds exposure

The stars are trailing very badly at 53mm focal length.  So that limits the types of pictures I could take on a tripod.  Especially when facing away from the celestrial poles.  As a test, I took a picture of the North celestrial pole to see the star trails.

Canon XTi, 53mm focal length, f/5.6, ISO 1600, 30 seconds exposure

I was off the mark a little bit.  The little dipper is off camera to the left but I did manage to capture all of Cassiopeia.  However, there isn’t very much else in the picture so it is pretty boring.

I would call Saturday a complete success.  I was able to recreate some of the picture I’ve seen on the Internet using their suggested settings.  I was able to prove to myself that the camera I plan to get, and the dark site available to me are both adequate for astrophotography.  This gives me some confident now to spend money on a DSLR carmera and mount.

I was really lucky, the sky cleared out soon after I had set up the camera.  Here is the picture, straight out of the camera.

Canon XTi DSLR, 17mm focal length, f/4, ISO 1600, 30 seconds exposure

So the first thing I notice is that ISO 1600 really captures a lot of light.  The picture from my Lumix TZ5 was not this bright even when I set the camera to 60 seconds exposure.  I import the picture into Adobe Lightroom 2 (great software) and played with the color temperature.  The picture is very red, likely from the street lights that’s all over the place.  So I changed the white balance and was able to get this picture.

Color corrected image

One thing I should point out is that I record all the images in RAW mode.  Lightroom has the ability to read Canon RAW formats directly so changing white balance doesn’t affect the picture quality like it would if the image was in JPEG.  The next thing I wanted to do is to bring out the sky as much as possible.  To do that, I increase the contrast as much as I could and reduced a lot of the colors in the foreground (ie, green).  Here is what the picture looks like.

Picture with high contrast

This is a pretty cool picture, and upon closer inspection you could see a lot of interesting stuff.  You could see most of Scorpius’ body.  His tail is right in the middle of the picture.  If you follow Scorpius’ stinger up and a little to the left, you can see M7.  To the right of M7 is M6, the butterfly cluster.  The Milky way is barely visible but you can see it in the constellation Sagittarius that is near the top of the picture.  If you look closely, you could see the Lagoon nebula by the bow of Sagittarius.  The line of dots on the left is an airplane flying into frame.

So this is very good news for me.  The test shows that even in such a light polluted area I was able to capture some very interested objects.  I can’t wait to head out to darker skies later.

The highest magnification I was able to use is 200x (15mm with 2.5x barlow).  I tried to use 300x magnification but the seeing last night could not handle something that high.  Jupiter at 300x was just too blurry and I couldn’t even see the brown bands anymore.

I’ll tried to get some images on Jupiter in a few weeks, after it moved a bit more so that I could get my telescope on it earlier.  Hopefully I could get some stable air for that.

Obviously Jerry is a professional photographer and I’m not, so I’ll need to improve my skills.  However, I think also my Lumix camera simply can’t compare to a real DSLR camera.  For example, I notice his big dipper picture he has the ISO setting to 1600 and exposure time to 60 seconds.  I can’t do that with the Lumix because I don’t have access to the ISO settings when I’m in starry night mode.  If I set the camera to manual mode (where I do have access to the ISO settings), I don’t have access to the exposure time.  The longest exposure time I have in manual mode is 1/8 seconds.

After I looked at the pictures in manual mode (ISO 1600, 1/8 seconds exposure), I notice that there are a lot of noise.  I think they’re trying to hide the fact that the Lumix is very noisy in high ISO mode so they made it not selectable when you’re using long exposures.

So I guess I’ll get myself a new camera first.  I’ve narrowed the choices down to the Canon XSi.  It had good reviews as a “regular” camera and it is also good for astrophotography.  So now I need to read all about camera, lens and how to take good pictures.

Scenic moonshot from West Yellowstone, ISO 250, f/4.9, 1/124 second

The next thing I wanted to do is to take a picture of a constellation closest to the North celestrial pole to see if it would minimize star trails.  The obvious target is the little dipper seeing that the North star (Polaris) is the last star of the handle.  So I set up the camera and took this:

Little dipper from West Yellowstone, ISO 100, f/3.3, 60 seconds exposure

The little dipper is not a very bright constellation, so it is a little hard to see in the picture.  The little dipper is very near the center of frame, slightly above and to the right of the tree.  Here is a zoomed in picture of the little dipper.

Little dipper from West Yellowstone, ISO 100, f/4.5, 60 seconds exposure.

The picture is zoomed in optically in the camera and not a crop and zoom from the first picture.  There are hardly any star trails in this picture even though it is zoomed and the exposure is set to 60 seconds.  The problem seems to be that the little dipper is just a bit too faint and needs more exposure time.  I would have liked to try 120 seconds but my Lumix camera has a maximum exposure time of 60 seconds.  It is still a pretty good picture.

Big and little dipper from West Yellowstone, ISO 100, F/3.3, 60 seconds exposure.

I decided to take a picture of both the big and little dipper in the same frame.  So I moved to another angle and took the picture above.  The big dipper is obviously on the lower left of the frame.  The little dipper is harder to spot because it is so much more faint.  You can locate the little dipper by drawing a line through the right most 2 stars of the big dipper’s pan.  The line will intersect the little dipper’s handle.  Don’t forget that the little dipper is upside down where as the big dipper is right side up.

My personal viewing site in West Yellowstone

There wasn’t much I could do until the sun goes down (at 9:30pm), so I took a few scenic shots of the moon.

Scenic moon shot from West Yellowstone, ISO100, f/4.6, 1/49sec.

And a closer shot from the same angle.

Scenic moon shot from West Yellowstone, ISO125, F/4.8, 1/60sec.

After the sun had set, I wanted to see if I could get better fixed tripod astrophotography here.  So I pointed my camera towards the Big Dipper and took a series of pictures.  Here’s the best one out of all of them.

Big Dipper at West Yellowstone, DMC-TZ5, ISO 100, f/3.3, 60 second exposure.

The picture turned out great.  I was able to use a longer exposure because I was pointing near the North celestrial pole.  This picture was taken with a 60 seconds exposure, the maximum allowed on the Lumix.

There are more pictures on the way, but they must be cropped and touched up first.