Moonshot

April 9, 2017

What is my moonshot project about? It is about taking a good picture of the Moon. You may think this is not very ambitious. Try it.

What I want to do is get a full frame image of the moon that I can blow up and put on my wall. I will most likely get images at full and at several phases. (Full moons are less interesting, but more on that later. Besides, during a full moon everyone is busy coping with their lunacy.)

I suppose the seed for this starts with my Dad. A family story tells about a 5 year old version of me sitting with him under the stars and learning the constellations. I apparently never forgave him when we moved far enough away that what I had learned wasn’t right anymore. My Dad also gave me his camera, a Canon FTb, along with the kit he has assembled. Two Vivitar Series 1 lenses, a 35-85mm f2.8 zoom, and Vivitar Series 1 100-300 mm along with a good traveling set of other interesting gear.

This interest in stars stuck with me even though the heavens had shifted, and one of my favorite school trips was to the planetarium for the classic constellation show.

Too my horror, I have discovered recently that planetariums don’t show constellation shows as often.

About a year ago I got a course from a company called the Great Courses called Our Night Sky. The Great Courses get college professors in front of a camera or sometimes just a microphone and have them talk about some subject. The Night Sky is 12 30 minute lectures on the things you can see at night presented by Professor Edward M. Murphy of the University of Virginia.

Professor Murphy suggests, when talking about the moon, that you actually go out and look up at it every night for a month. I recommend this too.

For one thing, it gives you an appreciation of the fact that our calendar months are approximately the amount of time it takes for the moon to go through a whole cycle.

For another, this is a natural wonder accessible to everyone. Even if you live near a city, the moon is so bright, you can see it.

It does take some planning though. For instance you need to find out when the moon is up. I have been using an app for my tablet for this. One specific to phases of the moon, and another that shows you the night sky. The first app is useful to know when the moon will come up. This second app is useful if you don’t know what direction the moon is going to rise from.

Prehistory

April 3, 2017

A long time ago, I sat out on my drive way and took some pictures of the moon. I know I was in South West Austin, and the it had to be from 1998 to 2005.

Like many photographer before me, I tried to take some pics of the moon. I no longer know what kind of gear I used, but I believe that I used a Canon FTb with a Vivitar Series 1 100 – 300mm zoom lens. I also used a vintage (even then) table top tripod.

Here is a challenge for you. Use a table top tripod on your drive way and take some pics of the moon. Go on. Get your face right down there to the concrete. (I could have gotten a sensible sized tripod. I could have gotten a table to go with the table top tripod. I did none of these things.)

The Canon FTb is a strictly manual camera with only a match needle light meter built in. This mean when you look through the view finder, there is a needle that indicates the amount of light in your scene. You adjust the aperture so that the aperture indicator in the view, is more or less lined up with the needle. (I was using print film. You can be pretty sloppy with your exposure on print film.)

This needle is black. The night sky is black. See a problem? Or maybe don’t see a problem? Actually, just move that part of the viewfinder to look at the moon, make the adjustment and then move back. (Remember the part about print film? If you ever get into film photography, just remember this magic phrase. Print film has a wide latitude. It will make sense later.)

The shots did not turn out well. Part of the reason is that the moon moves across the sky rather quickly. (If you actually understand astronomy, you know that last sentence is not exactly correct.) So to take a good picture of the moon, you need to have a short exposure time. (Relatively short.) The shots I took that had good exposure time, did not allow enough light to reach the film. The shots that did get enough light had the aperture open so long, the moon looks smeared across the frame. (So yes, even with the latitude of print film, you can still get an underexposed shot.)

The two most pleasing are the underexposed ones. These let you see the “seas” on the moon.

scan0011

Blurry, may be out of focus or simply moving to fast for the exposure time.

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Definitely moving too fast.

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The length of time keeps the moon “frozen” but is underexposed and grainy. (Insert chorus of “Let it Go” here…

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Another one with good shutter speed, but too slow film.

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The aperture was open too long. The details are washed out and the moon is moving across the frame. Also there is no graininess from underexposure.

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This one is close. Good time exposure that freezes the motion, but too much light that washes out the detail. Maybe can fix with Photoshop or similar?

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Another blurred edge and washed out details.

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Another one that is close.

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Omar reacting dangerously to moon light. Look out! Look out! Or is he just yawning?

 

 

October 29, 2009

This is a test of the category system.

Getting Started in Robotics

June 6, 2009

Hello again. This is Robotchef with this weeks article about robotics. This week we are going to discuss several ways to get started in robotics.

So how do I get started?

Get Help!
The single most important bit of advice I can give to a budding roboticist is to get help. Any activity is more fun when done with a group of like minded people. Such a group of people can offer help and encouragement as you work on your project. In addition you get to see their projects grow.

There are several ways to find this kind of help. Firstly, look for a robot group in your area. In the previous post I mentioned The Robot Group which operates in the Austin, TX area. The Dallas Personal Robotics Group operates out of the Dallas, TX area. The easiest way to find such a group is to use your favorite search engine with the words “robot” and the name of the city where you live.

If a live robot group is not a good choice for you, there are still a lot of live resources you can tap into. One such resource is forums. Forums are a kind of bulletin board. As a member, you post an article. Other members read your post and can make comments on it. For example, you could ask for recommendations for a micro-processor developers kit and get recommendations from other members of the forum. One such forum is the Society of Robots. (Hint: Forums can be a very useful way to find out about a lot of things. Try looking for forums the next time you are stumped by a problem.)

Still another way to find information is newsgroups. Newsgroups are a predecessor of forums that date back to the beginning of the internet. Newsgroups generally require a bit of software to gain access and you may have to pay to access the service. Most e-mail clients support newsgroups. You will want to contact your internet service provider about newsgroups to see if that is included with your service. A guide on how to get started is here. Here is a sample list of robot related newsgroups.

Lastly, another live way to use the internet to connect with people and learn about robots is e-mail lists. A simple way to look for such a group is to go to groups.yahoo.com or groups.google.com and type “robot” in the search area. Another way is to use your favorite search engine on the terms “robot” and “mail list”.

Membership in such a group is not requirement to build a robot, but it can add a lot to your robot building experience. After you get the hang of robot building, be sure to help other new members of whatever group you join.

Read!

Besides the internet, there are many many books on the subjects for robotics. Everything from getting started to the latest techniques in navigation or using robotic limbs to manipulate delicate objects.

For beginners, I personally recomend Mobile Robots by Joseph L. Jones and Anita M. Flynn. This is the book I got started with. Even if you do not want to build the two example robots in the book, you can learn a lot about the techniques used for motor control, sensors, and other things. As a note, it appears that the second edition of Mobile Robots is the subject of a lawsuit between Anita M. Flynn and the publisher A.K. Peters. All things being equal, I think I would recommend the first edition of the book.

In addition to books, there are also several magazines of interest to the robot building community. Two of these are Nuts and Volts and Servo Magazine

Finally, you should never forget the WWW. In addition to the forums, newsgroups and e-mail lists discussed earlier, there are Wiki’s, blogs and just plain old fashioned web pages. These will cover general robotics and also specific technologies that go into making a robot. (For example using accelerometers for dead reckoning navigation or a tilt sensor.)

OK, but how do I get started?

Right you are! There are three ways to get started right away. You can buy a kit. You can take an existing bit of electronics and ‘hack’ it or kit bash it. Lastly you can build one up from scratch.

Robot Kits

The world has a plethora of robot kits ready for you to build and requiring a range of skill. The great grand-daddy of all robot kits is the Heathkit Hero. A more recent but also wildly successful kit is the LEGO Mind Storms. Once again the internet is your friend and a search on your favorite engine can give you nearly endless lists for kits of all difficulties.

Kits are convenient. All the parts needed usually come with the kit along with detailed asembly instructions. All you need are some tools and some time. The downside to kits is that you may spend more time building them then in undestanding the principles used to make the kit work.

Hacks and Kit Bashing

The word hack has a long and varied history. In the case of this blog it refers to one of two things. Firstly hacking can be the art of taking an existing system, such as the iRobot Roomba. Check out “Hacking the Roomba“, and many other websites for things you can do with these little guys.

Kit bashing is the art of taking several kits and making something totally different or something far in excess of the original intent of the kits. It is a term that comes over from the Model Building community, but applies well to robotics.

As a homework assignment, I would have you look around you for things that you could hack. A good place to look is the toy department of whatever store you are in.

From Scratch

“In order to make an apple pie from scratch, you must first create the universe.” Carl Sagan

Of course you can always build your robot from scratch. You, and only you, get to make every decision of design. Will it be pink? Will it have a flame thrower?

The downside to this is that in order to make every decision, you have to know quite a bit about everything that goes into a robot. While hacking the Roomba limits you to a smallish round disk, you also get quite a bit of engineering taken care of for you. The power supply, recharge, and motion control is already designed into the package. Your hack adds on to it.

But if these limts are too, well limiting, you can always go from scratch.

In this case it is good to know about some of the small parts providers that you will be needing to get that from scratch robot out of your head and on the pavement.

Small Parts Inc.
DigiKey
Allied Electronics
Newark
Fry’s Home Electronics

OK Now What?

First, I hope this article has inspired you to reach out to the robot building community near you so you can learn more. Second, I hope it has inspired you to look around you and see what kinds of things you can turn into a robot.

The next article is going to be more nitty gritty detail. I am going to do a tear down of the toy I am going to hack. We are also going to start with a schematic. (I promised nitty gritty detail.)

See you next time!

What is a Robot?

May 26, 2009

Hi,This is Robot Chef!

This is the first in a series of blogs that will cover how to make a robot. The articles will be a mix of theory and nitty gritty, grease under your nails, grab your soldering iron details.

What is a robot anyway?

In the broadest sense, a robot is an autonomous machine that can perform some task. The autonomous part means that you don’t have to tell it what to do. A robot car would need you to tell it where to go, but would figure how to get there by itself. What task the robot performs is as varied as the human imagination. It can be anything from drilling holes in sheet metal, to teaching kids about American history.

Lots of things qualify as robots under this definition. The Voyager space probe is a kind of robot. There are robot planes, cars, submarines, dogs and cats. A lot of robots look like humans in some way. A lot of robots look like animals too. Still others look like nothing in nature.

Why do you want to make a robot?

Because they are cool! Ok, not get a date, or dance with the stars kinda cool, but hey sometimes you have to make sacrifices to accomplish the really important things in life, right?

There are many many reasons to build a robot. Since the Industrial Revolution people have been using machines as ways to replace human labor. The machines often are faster, more precise, and more repeatable then human craftsmen and women. This means that more things can be made in less time and for less money. Increasingly industrial robots have been part of this trend.

Robots are often used to perform tasks that are too dangerous for humans such as exploring the depths of the ocean or working in radio active environments. Several robots have been made to defuse bombs, or enter situations where a human might be shot.

Robots are labor saving devices. Robots have been made to do everything from serving tea to vacuuming your floors.

One of the greatly underestimated areas of robotics is in art. Robots have long been part of the movies and other forms of entertainment. This form of art is sometimes called animatronics. More formally, robots have entered captured the imagination of artists and the results can be seen in many galleries. One such gallery has a website here. For those of you that live near the Austin TX area there is a group of Robotic Artists there.

Finally one of the more important reason to build a robot is for education and research. Teaching people about robotics exposes them to a wealth of knowledge on modern technologies and how they are used. This can be a good way to teach kids and young adults about engineering. Even a simple robot will require knowledge of electrical engineering, software engineering, and mechanical engineering. (Don’t worry. You can make a robot without going to college.) Many people use robots to research new ideas and learn more about nature. This is done by making robots that mimic our understanding of the world around us. One such robot project sought to mimic the way insects move. This was done by giving them 6 legs and by modeling ideas about how insect nervous system swork.  More can be read about these robots here.

Are robots a new idea?

Nope. The word itself goes back to 1920 when it was used in the science fiction play ‘R.U.R. (Rossum’s Universal Robots)‘ by Karel Čapek. The word was coined by Karel’s brother, Josef Čapek, when Karel asked him for help naming the artificial beings in his play. Josef suggested roboti from the Czech word robota which means hard work especially that done by a serf.

The idea goes much farther back then that. Ancient Greek mythology tells of Hephaestus making mechanical servants. In the far east, a report of an artificial man that had the cheek to wink at the ladies of the court is reported to have happened between 1023-957 BCE. For more on the history of robots, go here.

Now what?

Hopefully this has whetted your appetite for robotics in general. I encourage you to think about what kind of robot you want to build or what kinds of things you want to know about robotics.There is wealth of information on the internet.

In the comming articles I will discuss various issues about making a robot. The next article will specifically talk about how to get started in robotics. From then on there should be a new article once a week. See you then!

Hello world!

May 22, 2009

Welcome to WordPress.com. This is your first post. Edit or delete it and start blogging!