Saturday, December 6, 2014

Cloud Iridescence

A fairly uncommon phenomenon is "Cloud Iridescence". I noticed this while watching my son-in-law, Brad, put up some Christmas lights on the roof of his house the day after Thanksgiving. The colors you see are a diffraction of the Sun's light passing through small water or ice droplets. Usually near the Sun, so I had to block the Sun with the roof top, otherwise the Sun's glare would overwhelm the effect. Brad was so intent on his chore that I don't think he was ever aware of the colorful site behind him.

Click on image for a larger view
Adjusting the image by reducing the highlights and increasing the detail in the shadows and reducing the exposure in software such as LightRoom brings out detail and color a bit better:


Monday, November 10, 2014

Heart Of America Star Party 2014

Another great Heart Of America Star Party has come and gone. Check out the website at HOASP.com. This yearly star party has been a great success for the Astronomical Society of Kansas City ever since it started in 2007. This year I did something I've been wanting to do for a while. I created a time lapse video of the event. On Thursday the night was too cloudy to shoot, but we got some great nights on Friday, Saturday and Sunday. Here is the video, which is best seen on a big monitor, full screen, speakers on and at the high resolution of 1080p (click on the little gear icon at the lower right of the video to change the resolution):



https://www.youtube.com/watch?v=zoeHr0GhVjo

My good friend, and astrophotographer, John Reed, also shot a time lapse and I have included it into the video. John is a member of the Central Arkansas Astronomical Society and has some really nice images taken with fairly simple equipment.  You can see his work here: Photography In The Dark.

On Saturday night, the clearest night of all three, I ran into a humidity problem. Anyone who gets into this hobby runs into this right away, especially if they live in the Mid West. Practically every night, the dew gets everything soaking wet. To keep the moisture off the lens of my camera, I use a heating strap that I made from a few resistors, wrapped in velcro. The dew heater gets its power from a 12 volt, 28 amp battery, which also gives power to my camera and time lapse rail by Dynamic Perception. As you can see in the video for the night of Oct 25, humidity crept in and started fogging the images. Unknown to me, the dew heater around my lens was not working (broken wire). Even so, what would normally be a bunch of deleted pictures, I decided to keep them and create the video anyway. I was pleasantly surprised with the soft quality it gives to the show. I replaced the broken dew heater with another one for the the next night.

On Sunday night, most everyone had gone home, since the star party was officially over. I decided to stay since it was supposed to be clear. I set up my time lapse equipment next to Master Observer Scott Kranz with his scope in the foreground, hoping to get him in action. But Scott was no where to be seen and you can see his telescope covered up in the video. Never the less, a nice crescent moon was a treat during the very windy twilight hours. The Milky Way set in the West just before clouds came in and ruined the rest of the night.

Our hobby is somewhat like fishing. We set up our telescopes in hopes of a good catch of starlight on a clear night, but sometimes we catch nothing because of clouds.

Monday, October 20, 2014

Thursday, October 16, 2014

Lunar Eclipse - Oct 8, 2014

Click on the image for a larger view
October 8, 2014, about 2 a.m., Gloria and I drove to Hillsdale Lake, KS, about a 20 minute drive from my home in Cleveland, MO. I set up my time lapse equipment and two tripods with my cameras to take pictures of the second Lunar Eclipse of the year. Clouds were lying low in the southwest, but clear over the rest of the sky and the Full Moon was shining brightly. At 4:17 a.m., the first bite from the shadow of the earth was taking place. Slowly, as the sky got darker, and more and more of the moon was being eclipsed by earth's shadow, we watched the stars appear above us.

Around 5:25, the moon turned to a beautiful, red ocher, brighter on one side, this being due to the fact that the moon did not go through the exact center of the earth's shadow. The picture above was taken with my 300mm f/4 Canon lens and Canon Xti. It is actually two images combined to show what it looked like in my binoculars. The planet Uranus was easily visible in binoculars. The picture of the moon was 4 seconds at ISO 400 and the stars were shot for 15 seconds. It is impossible to show this with one shot, so combining them is the only way.



Above, is the view across the lake, take with my 18mm f/3.5 Canon lens and the same Xti Canon camera. The exposure was 10 seconds at ISO 1600. This is also a double exposure, with the moon exposed for 10 seconds, but with the ISO at 200, essentially 3 stops slower.


This image is one taken from the set of time lapse pictures. The exposure for this shot was 25 seconds with a 10mm f/3.5 lens and my Canon T4i at ISO 3200. The longer exposure and higher ISO setting bring out many more stars, including the Andromeda galaxy at upper right.

A truly wonderful night. The only thing I could hear was an occasional fish jumping in the lake. At one point I watched a raccoon walk along the edge of the lake not noticing me, until I moved slightly, then it scooted into the bushes.

The next Lunar Eclipse will occur September 28, 2015.

Friday, April 25, 2014

Blood Moon and Great Blue Heron

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The first of four consecutive Lunar Eclipses has come and gone (see the end of this article to learn about the other three). Above is an excellent image by my good friend Jim Zanardi. I have created a time lapse video from my images and put it on YouTube here.



My wife, Gloria, and I spent the whole night watching and photographing it, April 14-15, 2014. It was an awesome sight, but wow it was cold! Temperatures were around 25 degrees and there was frost over everything, including my photo equipment. But I'm used to that and prepared for it. I have a dew heater, connected to a 12-volt battery, wrapped around the lens to keep the optics slightly warmer than the air around it.


Click on image for a larger view
We arrived at the site, Middle Creek Lake, just south of Louisburg, KS, around 6 p.m. I wanted to set up my time lapse rig in the daylight so that I wouldn't make any mistakes. Yeah, sure! I made plenty of mistakes, but I didn't find out about them until the next day. We had scouted out the lake a week before and found a nice place I could shoot the eclipse from. I had to park my car about 150 feet from the shore line, so I made a few trips carrying my gear. A cold wind was blowing from the north, but it was totally clear. I hoped the wind would die down as it usually does at night in the Mid-West.


I set up my new toy, a Dynamic Perception Stage Zero controller and rail that I purchased from my good friend and photographer, Wayne Thompson. I attached my iOptron Sky Tracker on the rail and my Canon 4Ti on top of it. My plan was to shoot the time lapse with my 10-22 mm lens at 10mm and have the Sky Tracker pan from left to right following the Moon and the rail move from West to East. After taking a few pictures of my set up in front of the lake I waited for the Moon to rise above the tree line.

Once I saw the Moon I started shooting a series of images with my 300mm f/4 lens on a tripod. I took a total of 166 images about every 5 seconds (counted in my head) hoping that was about right. It turned out okay, but maybe a shot every 2 to 3 seconds would have been smoother.

 I also took several wide angle pictures of the Moon rising with the lake as the foreground. Several ducks swam by and a reflection of moonlight on the lake created a peacefully serene scene.


Before the eclipse started and the moon was glaringly bright there was a surprise visit by a Great Blue Heron. I did not know about this until a few days later. Here are two of the best pics where he held still for the 30 seconds it took to get the image. He is right behind the piece of driftwood.

Right around totality I was looking at the eclipse with a pair of binoculars. I took them away from my eyes and moments later I saw a bright meteor flashing downward. This image shows the meteor and Mars to the upper right of the eclipsed moon. The streak at lower right is that of an airplane. The moon is pasted into the picture from one I took with telephoto lens to make it look more like what we actually saw that night.

In the above photo the Great Blue Heron and his shadow once again makes its appearance (lower left next to the driftwood). Here I have left the moon's image alone to show that a 30 second exposure wipes any detail out completely. Of course, a much shorter exposure would show detail on the moon and everything else would be way too dark.

The color changes between all of the images during the eclipse has not been modified. The color temperature setting on my camera was set to daylight through out and the color changes are actual changes from the light of the eclipsed moon.

Mistakes Not To Do The Next Time
Mistake #1. I started the time lapse sequence around 9 p.m. after the Moon had already risen. My plan was to shoot 30 second exposures with an interval of 2 seconds all night long. A few days before the event, I had taken some test shots of the almost full moon from my backyard to see what my exposures should be. Those tests told me that I could get away with shooting 30 seconds at f/3.5 and ISO 3200 all night. The Moon before eclipse would be really over exposed, but I could fix that afterward in Lightroom by lowering the exposure setting to bring out detail in the sky and clouds. But my test exposures on the evening of the event showed much more overexposure, so I kept the 30 second exposure but lowered the ISO to 1600, essentially, decreasing the exposure by 1 stop. As it turned out, even this was too much overexposure.

Mistake #2. I had never used the Dynamic Perception system until that night, but had done some test with it indoors to learn how to use it. Unfortunately I accidently put the drive belt on a little weird and it did not track like it should have.

Mistake #3. There are two ways to make the camera shoot a time lapse sequence with the rail. Option #1: Set up the controller to move camera the intended distance along the rail and have the camera settings set to shoot a 30 second exposure at the end of the move, then the controller delays 2 seconds to allow the image to download to the card before making another rail move. Option #2: Set up the controller to do all of the above and just set the camera to Bulb. The second option seemed the simplest. At home it seemed to work, but on the field it did not. What happened was the camera took a 30 second exposure, the rail moved and waited 2 seconds then sent a signal to the camera to take another exposure, but instead, the camera skipped the next shot. The camera did not have enough time to download the last image so it waited another 30 seconds until the controller released the last signal to shoot. So my intervals between shots were 34 seconds instead of 2 seconds. This made a rather quick and jittery time lapse, which is what you see in the final video. I am using a very fast card in my camera (Sandisk Extreme 63 G) which, on tests without the Dynamic Perception controller, allows me to shoot images with 2 second intervals easily. Apparently with the controller controlling the shots, the interval needs to be longer.

Mistake #4. I've been wanting to use some software that I've been reading about, but haven't had the time to try it out. I purchased and downloaded and ebook on using the software after the eclipse. My mistake was in not doing this before the eclipse. It would have corrected mistake #1. The software is LRTimelpase, by Gunther Wegner. In concert with Lightroom, it is an excellent piece of software for editing, grading and rendering a time lapse sequence. One very good part of the software is for what is known as "Holy Grail Day to Night" shooting. With this software, you can adjust exposure time or ISO settings during shooting to compensate for changing light conditions (which can be as much as 22 stops), then smooth out the transitions during the processing of the sequence.

Luckily, I was able to use the images I got to produce a video, although it could have been a lot better. I consider this a learning experience, so that for the next eclipse coming on October 8, 2014, I will be a little bit better prepared.

As I mentioned at the beginning, this was the first of four lunar eclipses within the span of 2 years. This is known as a tetrad. The last time we had a tetrad was in 2003-2004. The next tetrad will not happen for another 20 years, 2032-2033. There are several religious groups making a big to do about this current tetrad, but in fact there is nothing special about it. In the far distant future there will be no tetrads at all. To read more about this see article this by Fred Espenak.