Something to think about

I get the biggest kick out of all the UFO theory/conspiracy types out there. According to most of them
we've been visited by aliens numerous times who have done just about everything from building the pyramids to changing our history, and probably inventing ice cream. Just for arguments sake, lets assume there really is some form of other human-like beings out there. What is the possiblity that our tiny little dot of a planet lost in the vastness of this incredibly massive universe could ever be visited, much less found.

The operative words here are incredibly massive. Distances from point A to point B are so astronomical as to boggle even the most ardent of thinkers. Let's explore this idea for a moment.

So far, the fastest spacecraft we have ever sent into space is one of the Voyager probes launched decades ago. One of those probes has, by being sling shot around several planets, accelerated to something in the neighborhood of 70,000 mph. Now that's pretty fast. It only takes about 25,000 mph to escape the earths gravitational pull.

Okay, now think about this. In those decades since it was launched, it has just now...just now, reached the outer edges of our Solar System...a few billion or so miles out there. The next nearest star to us, not our sun, sits about 4.3 light years away. How far is a light year? Well light travels at 186,000 miles per second and a light year is how far a beam of light will travel in one year. At 186,000 miles per second, that is somewhere in the neighborhood of 586,569,000,000 miles. Multiply that times 4.3 and you get 25,633,091,520,000 miles just to the next nearest star to us...Astronomically speaking, that is like driving to the corner mom and pop store for a gallon of milk.

Now think about this. If we could accelerate a man-carrying spacecraft to 100,000 miles per hour...faster than even the Voyager probe, how long do you think it would take to get to that nearest star? That's about 28 miles per second...a lot slower than the speed of light. Give up? Well it would take about 32.7 billion years to get there. I don't know, but I think the warranty on that spacecraft would run out way before then. Factor in that most everything out there is thousands and millions of light years away, well, that's a far piece to travel. The Milky Way Galaxy...our neighborhood is 100,000 light years across.

So...for all you UFO Alien visitation types out there, the likelihood that an alien civilization could ever find us and swing by on their summer vacation, much less to stir up trouble during their visit doesn't sound so practical. And, forget about the idea that they could be way more advanced than we are and could possibly have figured out how to travel at the speed of light. It can't be done. There is this little annoying law of physics that says the faster you go, the heavier you become, so it requires more and more energy to continue to accelerate. So much extra, that by the time you accelerated to light speed, it would require an infinate amount of energy...and that is a show stopper.

There may be UFO's out there...more than likely though they are made right here by us.

Something to think about.

Keith

Photographing the Moon

Of all the night sky objects, the moon is by far the easiest to photograph. It is so bright and filled with
a changing array of shadows and objects that you can photograph on almost any clear night. Do so does require a little understanding of the technique, so lets talk about how to go about capturing the rugged beauty of our closest celestial neighbor.

What you will need is a tripod, a long lens...the longer the better, but something in the neighborhood of 300mm will do a good job, and a remote/cable release, and of course a camera, digital is prefered.
The camera settings are important but we'll talk about that later.

First of all, contrary to popular belief, the best time to photograph the moon is not during a full moon. The best time is during one of the partial phases of the moon. This is because during a full moon the light is almost face on to the surface and so there are no shadows being cast and so the moon shows no texture. During one of the phases of the moon, the light is at an angle and so the craters and mountain ranges will cast shadows and thus create textures that add interest and compositional values to your photograph.

You can photograph the full moon, but the best time to capture it is just after it rises above the
horizon. During those first few moments after moonrise, it will often have blood red or deep yellow color. This is because the light is travling through the thickest part of the atmosphere and shifts the spectrum to the red.

Let's talk about camera settings. What I do is to set the camera on Aperture Priority, but I also set the exposure metering mode to Spot Metering. This is where the camera will meter only the light seen in that small center square of your view finder. I also will shoot at 100 ISO in most cases. I will place the camera on a tripod for stability because I will be using a long lens...in my case a 500mm lens sometimes attached to a 1.4 teleconverter which will expand the focal length to 700mm. When combined with the 1.5 sensor conversion factor, the effective focal length will be in the neighborhood of 1000mm. sometimes I will use auto focus, sometimes I will use manual. My Sony A65 will highlite what is in focus when set on manual and I can often obtain a sharper image of certain subjects using it in that mode.

 

I use live view and point the camera/lens at the moon until it apears on the viewer screen and center it so the spot metering square is positioned on the bright part of the moons illuminated surface. The reason to use Spot metering is to avoid having the dark background surrounding the moon influence the exposure and probably causing the image to be washed out. I will use a cable release to avoid any unnecessary jiggling of the camera...and fire off a shot or two and view the results. I will use the zoom mode so as to get a good idea of how well the image is focused and to determine of the exposure if correct. I will also using the exposure +/- compensation to adjust the exposure up or down until I get the desired exposure.

After capturing the image, I will download to Photoshop and in most cases tightly crop the image to give it a closer look...and adjust the exposure and focus.

It's really that simple...and a lot of fun to try.

Keith

Escape

The last couple of months on the job have been rather strenuous. I'm an old school mainframe COBOL DB2 EDI programmer. Not many of us left. Oracle is the wave toward the future...so they say, but when a company has virtually all of their old legacy systems written in COBOL, well they gotta keep some of us old school guys around to maintain it until it can all be converted over to Oracle. It's big job for those involved and there are times when it becomes almost overwhelming, like recently. Our staff has been depleted to the point where in our EDI group two programmers are now supporting the work that six, actually seven, programmers at one time supported, but the work load has not let up, in fact it has increased. The stress levels have been sky high, and for old timers like myself, it takes a toll. I just don't handle it as well as I did when I was younger and as a consequence, I need an escape from time to time.


My neighbor, who also works where I do, has been dropping by once a week for some porch sitting time to chill out and allow some of the stress of the week to simmer down. This evening we continued in that endeavor spending time well into the evening chatting about past experiences. As he was about to leave we spent some time looking up at the clear evening sky. The Milky Way haze stretched like a silver ribbon straight overhead, and stars shined like diamonds. After a few minutes of discussing some of the natural night sky sights, he went on his way but I stood there a few more moments gazing up at the heavens and realized it had been a while since I last tried to photograph the night sky. I gathered my camera and tripod and headed over to Sledge Road, about a quarter mile away and spent about thirty minutes capturing an old house against the royal ribbon of the Milky Way. Just what the doctor ordered...my stress level went way down...at least for now.

Sometimes we need an escape, and the night sky offers a unique way to leave behind all the stuff of life that gets us down...simply by looking up.

Keith

Orions Belt

One of the more distinctive groups of stars in the winter night sky is Orions Belt. It is made up of three rather bright stars; Alnitak, a super giant star about 10,000 time brighter and 20 times the mass of our sun, Alnilam, another super giant blue white star about 18,000 brighter than our sun and 20 times the mass, and Mintaka, yet another giant about 7,000 times brighterand 20 times the mass of our sun. All three probably formed from the molecular clouds found in the constellation. All three are about 800 to 1000 light years from earth. Angling below them is Orions nebula, a star factory where new young stars are being formed.

Photographing Orion is rather easy as the stars stand out brightly on a clear winter night. As the summer approaches its end and fall filters into place, anticipation for the arrival of Orion grow quickly for those who find its form a fascinating image across the night sky.

Heres one from last April a few weeks before Orion disappeared for the summer. 50mm - f/6.3 - ISO 3200 - tracked for 40 seconds.

Night Portraits

 

A few months ago I ran across an article by Mark Gee, an astrophotographer from New Zealand, about how he made a series of night portraits using the Milky Way as a background (http://theartofnight.com/2014/03/under-the-milky-way-girls-by-starlight). The images he shared were stunning examples of the creative use of light. I decided to give it a try myself just to see if I could pull off something reasonably close to what he accomplished.

The hard part was finding a model who was willing to be up late in the evening. The most logical model was my wife Kris, but she tends to be a bit reluctant to do such things, so instead I was able to talk my son into helping.

Our original destination was the old barn located about three miles down the road. The location offers a good view of the southern and eastern sky and even with a sliver of the moon being visible at our appointed hour, it presence hovering above the horizon in the west had little impact on what I was trying to accomplish, but, we settled on the backyard out of convenience.

I set the camera on a small tripod I had built from spare parts that allowed the camera to sit about ten or twelve inches off the ground. Using an 18mm lens, I angled the camera just enough to gather in the sky and still capture him as he stood a few yards away. I manually focused on him using a light from his cell phone.

The technique was simple; he had to stand perfectly still for about 20 seconds while the camera made its exposure, then at the very end of the exposure process, I fired off my speedlight to illuminate him with a quick blast of light against the Milky Way backdrop. I purposely underexposed the image knowing that I would eventually boost it in Photoshop to bring out the dynamic light of the Milky Way, and I did not want to overcook the exposure on him.

The results were encouraging but the technique still requires some practice and a darker, brighter night to enhance the milky way. Regardless, it was a fun attempt at doing something different against the incredible diverse light of the night sky.

Keith

Light is Still the Key

 

In any kind of photography, light is the key ingredient. It’s not so much the quantity of light that is important, it is the quality of that light. When you view one of those amazing nature photographs taken by one of the amazing nature photographers what stands out the most is how they were able to use light to great effect. Light is the most important element when it comes to defining and creating a great photograph and this holds true even for astrophotography. The difference between a great astrophotography image and a generic landscape is the quality of light is almost always inherent in the night sky, it’s just really, really faint. That factor alone is what makes night sky photography a challenge, but one worth attempting.  

Photographing the night sky comes with all kinds of technical challenges, but even novice photographers possess most of the basic skills required to capture a fantastic shot of the Milky Way on a clear dark night. If they do lack anything, it is a lack of understanding about the night sky itself. Even though light is the key, composition plays off that key and without a clear and organized composition, even a wonderful night sky event will often fall short. 

I find myself expressing jealous feeling toward those who have the opportunity to photograph the night sky from a vantage point out west with its wonderful dark sky opportunities. It is there one can find amazing foreground objects to enhance the composition which is embellished by the brightness of the night sky. In Kentucky we have to contend with a lot of hazy and often overcast skies not to mention the abundance of light pollution. Even so, with a little research one can find a suitable location. Then it becomes a matter of being willing to be there and a little luck with the timing of a dark sky with a clear night. 

For night sky photography, the absence of light is what shapes the image. It is those dark areas that add character and drama. Break up those dark areas with glowing nebulas and star light and your image begins to glow with a resonance that is out of  this world, literally.

 

Capturing a Deep Sky Object

As I thumbed through the pages of the Backyard Astronomers handbook each image exploded off the pages with a brilliant flavor. I read about how the Hubble Space Telescope changed our view of the universe and I gazed at images that were clear and crisp and bright. I have also watched various video programs about visually exploring the wonders of the universe and how magical and exotic those parts of creation can be. These views were taken with expensive instruments so sensitive that the most distant reaches and faintest measures of light can be imaged. They are incredible and inspiring.

Orion Nebula - Where stars are born

Amateur astronomers have available today a myriad of small but powerful telescopes that removes much of the mystery behind navigating the night sky. Many of these are affordable, some maybe not so affordable except to the most die hard. They are capable of revealing and tracking a tremendous array of night sky objects using their computerized tracking software and drives. For those of us who must live on a tighter budget, well about all we can do is to sigh with envy and appreciate the contribution these amateur level instruments provide. But all is not lost.

The past year or so I began photographing the night sky and following the work of others who produce amazing images. I’ve also read about and followed several amateur astronomers who photograph deep sky object using their sophisticated computer tracking telescopes. Some of the results they obtain are truly amazing. This season, I began to explore how to capture some of the more easily found deep sky objects. What I discovered is that even without an high dollar computerized astronomical instrument, you can capture some incredible images using simple homebuilt tracking equipment and basic photographic cameras and lenses.

In a previous blog entry, I wrote about building a manually operated barndoor tracker. For wider area photographs, this manually operated device worked very well, but in order to photograph deep sky objects, you need to have a motorized version that tracks the sky more smoothly. The previous image shown above and the one below illustrate the results that can be obtained by adding a simple 1 RPM motor to the tracker. Using this setup and with some careful identification, I’ve been able to track and photograph a few deep sky objects. The easiest of these is Orion’s Nebula in the constellation Orion.

 

 

In the northern hemisphere Orion is primarily a winter constellation and the nebula located in Sword of the Orion’s belt is easily seen even with the naked eye or with a pair of binoculars. Last winter I attached my 500mm lens to the tracker and pointed it toward the nebula to see what would happen. Once I had the tracker properly aligned as discussed in that previous blog post, I experimented with the exposures and the tracking. What resulted far exceeded what I expected.

One of the techniques more serious photographers use to capture deep sky objects is what is called stacking. This technique involves taking a series of images (several hundred in some cases) using relatively short exposure times and then building the image one layer/stack at a time using software written for such techniques. If you know how to do it and are a whiz kid in Photoshop, you can indeed create some amazing images. The images I took were the result of a single image that was slightly tweaked in Photoshop. The result obtained were pretty good and much easier to do.

First I setup the camera at 3200 ISO and opened the aperture all the way, in this instance f/6.3 at 500mm. I took a short test shot to verify I had the nebula located in the view finder then I turned on the motor drive and allowed it to run for a few seconds to dampen any startup vibrations. Using a cable release I fired off a series of exposures ranging from a few seconds upwards to 30 seconds and over a minute. What I discovered was that the 20 second shot provided the best combination of detail, color, and depth. With a bit of cropping, a little tweak in Photoshop to boost the saturation, dampen the star glare hovering inside the nebula, and making sure the sky was black, the image materialized into one where the lacy wisps of glowing gases and starlight became visible with good definition and clarity.

The clarity of the image proved just how accurately the motorized barn door tracker worked. Total out of pocket cost to build it was less than $40.00 using materials already on hand, the largest expense being the 1rpm motor that cost about $25.00. Not everyone has a 500mm lens laying around to use, but many people do have 70 – 200 or 75 – 300 lenses. These will work almost as well, but may not crop as tightly.

Another deep sky object that is relatively easy to find is the nearby galaxy Andromeda, also known as M31. Andromeda is the closest next galaxy to our own Milky Way Galaxy, but it is considerably larger, at least twice the size, but is shaped similar to our own as a magnificent spiral. Andromeda is actually moving rapidly toward us and in a few billion or so years it will collide with the Milky Way and forever change the shape of both of them. Andromeda is visible by mid-summer above the northeastern horizon and continues to rise higher into the night sky as the summer progresses and if you are willing to stay out until the wee-hours of the morning you will be able to find it hovering high enough in the sky to get above the horizon light polution glare. It is located oddly enough in the constellation Andromeda and by using a star chart and some experimenting, you should be able to find it by late June or early July around midnight about 30 degrees or so above the horizon in the middle latitudes of North America. It is surprisingly quite a large object in the night sky and is just visible as a dim smudge to the naked eye on a clear dark evening. The light gathering ability of the camera will capture the dim light rather nicely.

Andromeda hovers in the summer sky

 

The photographing techniques are the same as mentioned above and it can become one of the most exciting objects to photograph. I'm still working on obtaining a really clear image, but I have managed to capture a few decent images. It is much dimmer than the Orion Nebula and this requires a little longer exposure, and the dictates a much tighter tolerance on the alignment of the tracker.

Capturing deep sky objects are well within the capabilities of the average photographer and certainly is worth the effort. Give it a try, and along the way you might discover something exciting about the night sky.

 

Keith

 

A Night Under the Stars

Have you ever stood under the night canopy unobstructed by trees or buildings with nothing around you, no city lights, nothing but open space as if sitting inside a giant bubble with the night sky arched overhead?

If you live east of the Mississippi River, chances are you have not experienced such a moment. Except for a few isolated locations, the eastern half of the United States is more densely populated and the idea of a dark sky is nullified by the ambient glow dome of city lights at night. Even if you live out in the country like I do, the horizon in almost all directions is influenced by that dome of light as it encroaches upwards and spreads above the horizon. It may look dark to your eyes, but the light is there subtly filtering what hovers above us. Further west there are large areas where one can still visit the night sky almost unencumbered by this man made light pollution dome.

 

 

Many years ago I spent a year in Denver Colorado and would commute home to Oklahoma two or three times a month. Most of the time I would drive taking route 70 across eastern Colorado and western Kansas. During the winter months it would get dark rather early and by the time I crossed into Kansas the night sky was filled with stars. It was an experience I found fascinating. During one of those drives home, the comet Hale Bopp hovered behind my left shoulder as I drove. It was so clear and bright that the comet acted almost like a mini moon. I even stopped once along the highway and stood alone in the open. At the moment no other cars were insight. Just me and the giant dome of a dark sky filled with uncountable stars, and Hale Bopp glowing against a pure black background.

Before then, I had never witnessed a night in such clarity. Since then, I have rarely been able to examine the night from such a vantage point. I now live in Kentucky which as a location is far from being ideal for observing the night sky. Even so, on rare occasions, the evening will blossom into a clear magical moment when the summer Milky Way sings its melody with such clarity, the light domes along the horizon fail to stifle its mood.

Those are the evenings that make the late nights worth the effort. Last summer I encountered such a moment and found myself standing next to an old barn surrounded by cornfields. The evening was late, but the normal sleepy nature I might have at that hour all but evaporated under that canopy filled with the light of stars. The Milky Way arched high into the night and was so bright I could just make out using just my eyes ‘The Dark Horse’ as it reared above Sagittarius to the southwest. In that part of the sky, save for a distant security light, the light pollution was negligible.  Even though it was deep into the summer season, the evening was cool and delightful having been quenched of its heat and haze by a cold front that passed through the day before. A light windbreaker was necessary to keep the chill out.

 

 

For several hours, well past midnight, I pointed the camera toward various points in the sky and ran the tracker to capture the dim glow of distant clouds of gas and stars too faint to see visually. Even with my limited equipment, it was adequate enough to absorb in good detail the few photons of light that had in some cases traveled for thousands of years before falling into and through my lens. For a location better known for summer hazy skies, it was a once in a season opportunity to experience a grand adventure observing what the night sky offers. For a few brief hours, the dark skies became brilliant in their own unique way. What it said was, "There is more here than meets the eye".

I was able to find Andromeda and tracked it for several minutes capturing in a single image its mystical glow. What a treat it was, that evening, to share a few hours alone with sights few venture to find, and even fewer try to capture. A night under the stars, a special moment, and a unique journey involving moment and place when all the elements come together to create a revelation of time and space.

Keith

Sail Away

There are times when I am standing in the middle of a field on a clear moonless night I can almost imagine what it must have been like to sail across the ocean under a sky unencumbered by light pollution. Indeed, I have sailed a number of times several miles off shore many years ago on a clear evening when I was stationed in Oregon during my stint in the U.S. Coast Guard. It was amazing to see the stars above and feel the sea rolling beneath my stance. The emotions lifted me above the moment to where I felt suspended between the earth and the sky. It was as though I was about to sail away toward adventures yet discovered. Here is a video I originally made about a year ago, but revamped recently along that theme I believe you may enjoy. Music is 'Orinoco Flow' by Enya.

 

 

NightScapes - Timelapse

Most of us have probably seen them already. You know, those amazing time lapse videos made of the
night sky. Some of them are simply spectacular and defy the senses. Photographers such Sean Parker, or Mark Gee, just to name a couple, have produced some incredible footage that generates not only awe but envy from other photographers of the night sky.

This season I began to explore what is required to take such footage. Sounds easy enough at first glance, but in reality, there is more to it than what may first appear. As I studied the work of others I tried to piece together some of the visual effects and photographic techiques they were using. What I discovered is that what is most important is timing, time afield, and location, and of course knowing how to capture the night sky from a techical point of view.

You for the most part must have a dark, clear night and in Kentucky finding that on a consistent basis is probelmatic at best. Each month there is a period of a week or ten days so where the moon remains hidden until either the very early hours of the morning or it sets very early in the evening. The trick is the timing. In Kentucky you may have a dark sky night, but odds are you will also have a lot of clouds. Broken clouds by themselves are not a major issue unless of course they completely block the sky. They can also present a problem by reflecting a lot of light pollution from the ground. The worse kind of clouds are the thin hazy type. They tend to act like a mirror and create a lot of reflected light plus they obscure the Milky Way to the point where it becomes difficult at best to photograph it.

Time afield is also important. The very nature of the process requires that you spend many hours out at night...sometimes until the wee hours of the morning. This presents a problem for those of us who must work a regular job. In most cases we are relegated to weekends or vacation time. But to get the shots, you have to make the time and be there when the sky is at its prime.

 

Location is just as important as the other elements. Most of the time I simply step into my backyard out of convenience. This serves well to perfect the technique but hardly offers one of those great locations that is so important in the presentation. I am often confronted with the neighbors outdoor lights flooding the area, or other security lights down the street arching a dome of light across the trees. Down the road a couple of miles stands an old barn just off the country road. I will on occasion drive over there and step into the field using the barn as my foreground. The location offers at least a measure of visual interest plus a decent view of the night sky and is relatively dark. I have planned on, but have yet been able to make the trip (this thing called work tends to interfere), spending a couple days over at Red River Gorge that appears to offer some spectacular landscapes to join with the night sky. Before the summer is out, I will make that trip and hopfully capture one of those amazing night sky moments.

So how do you capture a time lapse video using a digital SLR camera? Well, you gotta use what is called a intervelometer. This is a remote electonic trigger device that plugs into the remote outlet on the camera. It allows for the setting of the length of exposure plus the interval between exposures and the number of total exposures. They vary in cost, but I found a real good one for under $30.00 for my camera.

Basically the way it works is you set the camera up the same way you would for a single photo...manual shutter (bulb), infinity focus, ISO...all that. Then you set the intervelometer to the length of the shutter exposure say 30 seconds, the interval between the each exposure, say 35 seconds, and how many exposures you want to take...or you can set you camera shutter length to 30 seconds, and set the intervelometer interval to something longer than 30 seconds...just depends on what works easiest.

Place the camera on a sturdy tripod ( no tracking is required ) and point the camera in the desired direction, then fire it off. The intervelometer does the rest. It now becomes a waiting game. The number of exposures required vary depending on what you are wanting to accomplish. Generally speaking it takes 24 individual exposures to produce one second of video. To get five seconds of video, would require about 120 exposures. With one exposure being made every 30 seconds, this will require at least one hour of shooting time.

After you capture all the images, your job is only half done. You must now download these images into some kind of software that allows for the rendering of video sequence. I do not have the space here to discuss what software packages are available, but there are a number of variations available. Some are cheap, some are not. I recommend you do some reading about the subject. I simply use the same software package I use for my slide show presentations...Magix Extreme Photostory. It took some experimentation, but figured out how to make it work...although, the video quality falls a bit short, it is a good package to learn the ropes with.

Capturing time lapse is fun, but labor and time intensive. The amount of time required vs the amount of footage produced does not always equal out evenly. Below I have attached a short segment of some of my early attempts, and also provided a couple of links to some professionaly done time lapse videos. Please enjoy.

Links:  https://www.facebook.com/markgphoto

            https://www.facebook.com/SeanParkerPhotography



Keith

The Star Tracker

 

Red Green from the infamous Canadian PBS series The Red Green Show would be proud of my star tracker. On his program he builds all kinds of workable…sort of…contraptions using not much more than junk spare parts and duct tape. My star tracker certainly looks like something along that line. Amazingly, it works better than I could have imagined.  

About a year ago after watching some amazing videos of the night sky and gazing upon some magnificent still images of the Milky Way. I began to wonder how the photographers managed to capture such fantastic images. What little night sky photography I had tried resulted in barely more than capturing a few dozen points of light against a dark background. Nothing spectacular about that. But, I was intrigued and started to research how to build what was called a Barn Door Star Tracker.

The concept of how they worked seemed simple enough. Their operation is based on being able to pivot the camera at the right latitude angle, at the same rate the star fields rotate across the sky.It requires a hinged platform that allows for pointing the camera in any direction, and a drive shaft, made from a ¼ inch 20 carriage threaded bolt placed at a specified distance from the hinge to allow for the proper degree of rotation at one full revolution per minute. The next weekend after some trial and error I managed to create a working model that manually tracked the night sky and began to experiment in capturing what I hoped would become amazing images of the Milky Way. Initial results were encouraging yet not quite what I was hoping for. The prototype proved a bit cumbersome to use and align with the pole star. The alignment part I was to discover was the key to its operation. Improperly align the devise and the tracking would be way off. I do not have the space for an indepth discussion on how to align the tracker, but there are plenty of websites that cover this information.

Eventually, I rebuilt the contraption and mounted it on an old telescope tripod that had been sitting in the attic for several years. This new production model proved much more capable and easier to operate and through the summer, my technique also improved along with my knowledge about the night sky. That knowledge proved vital in being able to identify potential subject matter. 

The trick to making it work correctly is, as mentioned previously, proper alignment along with smooth tracking by hand. The tracking part using a wide angle lens is relatively simple; ¼ turn of the drive shaft handle every 15 seconds will allow you to take exposures upwards to several minutes long with good results. 

The exposure setting on your camera is simple.  The tracker should be secured to a heavy duty solid tripod to reduce vibrations. Set the camera to Manual exposure and manual focus. I usually shoot in JPEG, but RAW would be better if you know how to process that kind of image. Select the BULB setting for the shutter. ISO setting should probably begin at 800, but 1600 and 3200 with most cameras will work with very little noise issues. A point to remember is that an ISO setting of 1600 will require half the exposure time to obtain the equivalent exposure value when set at 800. So a two minute exposure at 1600 is the equivalent of a 4 minute exposure at 800. You will see more noise at 1600 or 3200, but most of that can be cleaned up in post processing. I’ve shot upwards to 6400 without too much noise problems, but they did require some cleaning.

 

Open the aperture all the way open (f/2.8, f/3.5…ect). Use a cable release and some kind of timer (stop watch, or just count to yourself) so you can determine the exposure length. Set the focus to infinity (some lenses have an infinity setting offset slightly from the infinity mark) Press the remote shutter release and hold and rotate the drive shaft at the 1rpm interval rate until you reach your determined exposure time and release…it’s that simple. You can adjust the time as needed to obtain different results. Oddly enough, using a wide angle lens, anything upwards to 30 seconds and you do not need to track the sky. The star trailing is so insignificant and the stars themselves are so small, the stars retain their sharp pin point appearance. Over 30 seconds and the stars will begin to show signs of trails if not tracked. 

I’ve been able to go as long as seven minutes but most exposures from one to three minutes are more typical. When you use a longer focal length lens, then the manual tracking becomes more cumbersome. Up to about a 40mm lens, you can stick with the ¼ turn every 15 seconds equation. Using a 50mm upwards to 80mm lens and you will need to increase the rate to something like 1/8 of a turn every 7 to 8 seconds…roughly two times as often to obtain the 1 revolution/minute rate. Push the lens out longer than 80mm and you will need to manually turn the drive shaft pretty much continuously. That can be difficult to do without causing vibrations in the tracker that result in blurred images. 

One of the easiest ways to get around that is to employ an electric motor to turn the drive shaft. Now, I’ve read numerous articles and thumbed through countless diagrams for how to do this using stepper motors with gears and electronic devises that control the motor voltage. That is all fine and good if you are an electronic wiz-kid and mechanical engineer. Some of these contraptions can end up costing hundreds of dollars. Thing is, you don’t have to do that. Let me explain. 

The idea behind employing an electric motor drive is to generate a continuous rotation of the drive shaft to make the tracker follow the rotation of the sky precisely without having to do it by hand. This allows you to use longer focal length lenses so you can capture deep sky objects at least reasonably well.  

In comes Red Green again. Think about it. What happens when you manually rotate the drive shaft? You use your finger to gently turn the handle ¼ turn every 15 seconds to rotate the shaft 1 full turn every 60 seconds. So, the logical thing would be to replace your finger by using a 6 to 12volt 1 rpm electric motor. A little research resulted in finding such a motor on the ServoCity website for about $25.00.  

Using a little Red Green ingenuity, I attached the motor using a wooden extension and replaced my finger by using a short piece of coat hanger bent into an elongated Z. I attached the hanger wire to the motor using a short piece of plastic tubing…aligned the motor drive as closely as I could to the tracker drive shaft. Then using two 6v flashlight batteries wired to create 12v, I connected the motor and power source using copper wire and alligator clips. The first test run that night proved the reliability and accuracy of the contraption. Oddly enough, this is not rocket science…just requires some simple understanding of the principle involved. 

You can of course use a 2 rpm motor attached thru a rheostat of some type to control the voltage so you can fine turn the motor timing. The one I created tended to run a little slower than 1 rpm especially when using a heavy 50-500mm lens, but it still had plenty of torque to turn the drive and was accurate enough to capture an image reasonably well. 

Orion Nebula Photographed using Motorized Star Tracker

The main problem I had using the heavy lens was to keep the alignment accurate. By rotating the lens in one direction and then to another, the weight of the lens caused the tracker to warp slightly, just enough to throw off the alignment. So with each repositioning of the lens, I had to realign the tracker to ensure proper tracking. 

Designs of a Barndoor Tracker (also called a Scotch Mount) are varied and creative. They all work on the same principle and some are more complex than others.  You can search on the internet for barndoor trackers and find all kinds of designs and plans. I’ve listed a few below. They are relatively simple to build, pretty easy to use, and open us a whole new world of photography.

 

Keith 

http://www.homebuiltastronomy.com/barndoor/ 

http://astunit.com/atm.php?topic=handscotch 

http://davetrott.com/inventions/double-arm-barn-door-drive/ 

http://www.astropix.com/BGDA/SAMPLE2/SAMPLE2.HTM

 

 

A Conversation With the Stars

A family of coyotes howled together somewhere across the corn stubble field north of my location, their serenade echoing off the side of an old barn and filtered through the surrounding tall trees. The moon approached the last vestiges of its monthly cycle and would remain hidden for several more hours so the evening was forecast as dark and clear. The thick hoodie I wore was most welcome as a light breeze stirred the night air into a colder than expected evening and I pulled the hood over my ears to keep out the chill. After my eyes adjusted to the darkness, the brilliance of the evening sky with its countless points of light dancing in the night air played out their opening song before the main performance. For the next several hours as the night deepened, the stars and I carried on an ever more interesting conversation.

A few of the planets spoke first as they hovered as bright sparks of light set apart from all the others. Massive Jupiter shouted the loudest and I lifted a pair of binoculars to take a closer look at what it was saying. Several tiny points of light extended to one side of its intense glow...three of its moons waved back and bid me welcome. A thin layer of clouds almost to opaque to notice drifted across and created a hallow effect around Jupiter. High in the southeastern sky appeared another point of light was glowing with a soft amber hue...Mars said, "I too want to join tonight's conversation."

Straight overhead where the stars appeared most brilliant the sky was much darker in texture. Along the horizon just above the tree line a feint but warm shallow light pollution glow highlighted the taller trees against the background making them appear as mysterious marching apparitions.

To the west the warrior Orion drew his bow above the horizon. His distinctive and grand pose shouted with confidence. Hovering amongst his sword a massive cloud of gas where new stars are born was set alight with their newly formed energy.

I rotated the finder scope on the star tracker and aligned it with Polaris offset just enough toward a sister star called Alkaid to allow for a proper track. The 1 rpm motor drive was connected and generated its distinctive hum as it turned the tracking drive shaft. Using a large 500mm lens I drew his sword closer in so I could hear better what he was saying and captured for the first time a hidden world where those stars were born.

A rather shy and quiet part of the sky gained my attention and I rotated the camera toward its depths, reconnected the drive motor and opened the shutter. A full minute passed before the exposure was complete. What appeared as a dark patch of sky spoke with more confidence as newer stars were revealed in the image. I realized they were there all along, speaking softly just waiting for someone to capture their soft glow.

All through the evening the stars and I continued our conversation, they would say, "Look over this way for here you will find something amazing," and I would. No boundaries slowed the moments and as one conversation died down, a newer one began when other portions of the sky rose above the horizon. As many stars as there were, they were only the outskirts of a greater city of stars that eventually came into view. First, the head of Scorpius raised its three stars above the treeline, its tail and stinger arching just out of sight. Below them following shortly thereafter arose Antares glowing with a bright, orange hue. Before long the heart of the Milky Way made its first appearance and joined in our conversation. As the camera hummed and the tracking motor purred I followed the sky to the left of Antares and a most amazing sight materialized. Thousands of stars were singing across a giant coliseum filled with glowing gases and swirling dust clouds of such size and portions, simply to comprehend the vast array of their place amongst the universe boggles the mind. On the upper right reared the stallion of the Dark Horse of the Milky Way. Just below where the brightest part of the glow filled the view was the center of the Galaxy. It's hard to imagine just how far away it truly is...some 26,000 light years...or put into another perspective...the light I captured on that evening began its journey some 26,000 years ago to finally be captured by the sensor of my camera.

As the night drew into and well past the early hours of the morning, my internal clock suggested it was time to call an end to this marvelous conversation. Reluctantly, I began to shut down the mechanisms by which I visually communicated with the stars, and I when crawled into a safe and much warmer bed, my mind continued to stir about the marvelous revelations the stars we so kind to share with me. I knew this moment was to continue and just postponed until another time, another dark evening until I could again explore the amazing stories told through a conversation with the stars.

Keith

Where Stars are Born

Back in October 1957 even though I was a little over 5 years old, I remember the impact that Sputnik had on the world and myself. For the first time I began to look toward the night sky and wonder about what was out there. I remember looking up one evening shortly after Sputnik was launched and saw this tiny glowing dot moving rather quickly across the heavens. I discovered later that I had for the first time seen Sputnik as it orbited high overhead reflecting the sun off of its shiny outer skin. How amazing it was to think of such a thing. For the first time man had actually broken free from the bonds of earth and sent an object circling the globe. Those first few weeks of wonder sparked within me an ever growing facination with the night sky.

Fast forward 57 years. I have connected my digital camera to a tracking device built from spare parts and plans found on the internet. Slowly and consistently by hand I turn the driveshaft that mimics the rotation of the earth and allows the camera to track for long periods of time one point in space. One mnute then two...and I release the cable shutter control. Within a second the image appears and what I see excites me as much as Sputnik did all those years ago. The digital camera with its light gathering ability and lens reveals the night sky in all of its glory. Our eyes just are not sensitive enough to gather in enough light so we can see naturally what floats above our world every night. But the camera makes up for all of that.

There are amazing colors and formations we never knew were there. Areas of glowing gases and dust fill the night sky across the lacy arch of the Milky Way...our home galaxy. Filled with an estimated 200 to 400 billion stars, it is our home amongst the billions of other galaxies scatter across the universe. Within it's realm places where stars are born, are recylced, and born again play out across a timeline unimaginable to our short span of life. Not so long ago, the Hubble Space Telescope pointed its eye toward a dark area in the sky that covered no more than the field of view as seen through a sodastraw. For a week or so it remained locked into positon making its exposure and when the image was finally processed, what was discovered astounded the scientists. Over 10,000 new galaxcies materialized and stretched about as far from us as you could possibly go. Imagine for a moment just how vast the universe is....kind of boggles the mind.

What a journey so far it has been, and I am just beginning to discover this facinating form of photography. I am not an Astrophysicist, just an ordinary photographer whose imagination takes him on amazing journeys of discovery. My first real season to photograph the night sky started as a trial and error process. By the end of that first summer what began with crude and sometimes shakey images began to demonstrate a new found confidence and excitement about the craft. By season two, the manually activated tracker was augmented by a 1 rpm motor that provides a steadier, long term exposure capability and I am just now beginning to tap into it potential.

NightScapes is simply a way to share what I discover as I continue to perfect the technique and find more time to explore this amazing form of photography. Kentucky although not the best location for night sky observations, does have its amazing moments inspite of the light pollution and often cloudy skies. As I stand in the middle of field on a clear dark night and see the brilliance of the night sky arch overhead, the excitment I feel and anticipation that fills my moment comes not from who I am today, but from the young boy whose facination was jump started by that tiny sphere called Sputnik so many years ago. I hope you enjoy the journey.

Keith