Monday, January 30, 2012

Can we build a planet from asteroids?

My original plan for today was to write a blog post about something different, but I haven't gotten my sleep the last few days and my mind started wandering. That's never a good thing...
Anyhow, I had this thought about the asteroid belt between Mars and Jupiter: Would it be possible to use the asteroids to build a planet?
I would like to mention that I have no real education in these matters so these are just my thoughts. Also as I said I haven't been sleeping enough lately so my mind works in mysterious ways at the moment.
If we had rockets strong enough to slow down the orbits of the asteroids to make them collide with each other at low speed differences*, could that make them stick together and form a larger planet? If it's possible to make them collide at low speed differences the individual gravity of each asteroid would join together to make a single point of gravity over time I guess. If that time is 100 years or 100 000 years, or even more, is not the point. If we can pile on asteroids on Ceres to make it larger than the Moon, that would be awesome.
We might also have to take into account that to actually hit one asteroid with another asteroid it's probably similar to shooting the head of a thumbtack from a mile away...
Then there's Jupiter. The massive gravity from Jupiter might rip the asteroids away from each other before they have a chance to join forces. Even after it could too I guess.
Maybe someone with real knowledge about these things will tell me it's impossible, but hey if we don't dream we don't progress. Maybe someday in the future we have the kind of energy that's needed to boost rockets like that.

*If two cars collide head on the damage is greater than if one car rear-ends the other car when both cars are traveling at about the same speed.

Friday, January 27, 2012

Photos of the sky

One thing that I like to take photos of is the sky. Not just the night sky. Also not just sunsets even if a sunset can be very beautiful. After I've taken photos of the sky I usually use Canon's Digital Photo Professional program to edit the RAW files. Sometimes the result becomes amazing and sometimes it doesn't. It all depends on if I overdo it or not.
Here's a few examples of sky photos that I have edited like that. The left side is the unedited and the right side is the edited.
Taken during a thunderstorm at night
Taken at sunrise
Taken late in the afternoon
Taken at sunset
Taken at sunset

Here's an example of when the sunset looks that colourful even without the help of photo editing software.
Taken at sunset and no editing done

Wednesday, January 25, 2012

Rules for Quidditch with tennis ball and piassava brooms

This is something I found hidden in the depths of my computer. I wrote it many years ago as a joke to my nephew. I hope someone else enjoys it too. I only spent about 30-45 minutes translating it from Swedish so let me know if you find something grammatically incorrect.

Rules for Quidditch with tennis ball and piassava brooms
01. If you join the game, don't cry about it.
02. Anything that isn't explicitly illegal is legal.
03. Breaking of rules results in a 10 point reduction.
04. The referee's interpretation of the rules is law.
05. It is not allowed to pull on another player's clothes, hair or broom.
06. It is not allowed to claw, punch, kick, knee, or headbutt any other players.
07. It is not allowed to use the broom as a weapon.
08. All players should keep their bodily fluids to themselves. So it is not allowed to spit, pee, or bleed on another player.
09. A player's equipment is a piassava broom, shoes, socks, shorts and a shirt. Underwear is optional.
10. The ball should be a regular tennis ball. Although a colourful tennis ball is of course much more fun than a regular boring green/yellow one.
11. Each player as well as the referee uses one (1) piassava broom as a stick horse with the broom part towards the ground.
12. Each team should have their own coloured brooms. The crazier the colour the better.
13. Each team should have their own coloured shirts. Preferably the same colour as the brooms.
14. Each team has seven (7) players. One (1) goaltender, three (3) attackers, two (2) defenders and one (1) small skinny bloke.
15. The goaltender should do his/her best to defend the own goal. If he/she manages to get the ball he/she will then throw it to one of the attackers. Preferably one of the attackers in his/her own team.
16. The defenders should try to take the ball from the attackers in the opposing team and then throw the ball to one of the attackers in his/her own team.
17. The goaltender and the defenders are not allowed to throw the ball to each other.
18. The attackers should try to score a goal.
19. The attackers are not allowed to take the ball back from the opposing team's defenders or goaltender.
20. The small skinny bloke should run around and look for small flying golden balls.
21. The field is made up by two (2) halves. On the own half you have the goaltender and the defenders. They are not allowed to cross midfield into the opposite team's half. On the opposite team's half are the attackers. They are not allowed to cross midfield into the own half. The small skinny bloke can move anywhere he wants.
22. The distance between the goals should be about 20 metres. Other than that the field can be any size you want.
23. Players can move freely all over the half they are allowed to be on.
24. There is no out-of-bounds so as long as nobody (except the small skinny bloke) crosses the centre line they can go wherever they want.
25. The goals should be made of a hula hoop on the ground.
26. An attacker scores a goal if he can make the ball land in, or bounce inside the hula hoop.
27. Nobody besides the attackers are allowed to score goals.
28. You're not allowed to score a goal from behind the front-end of the hula hoop.
29. If a team scores a goal they get 10 points.
30. First team to 150 points win.
31. If the small skinny bloke finds a small flying golden ball his/her team automagically win.
32. There are no small flying golden balls.

Monday, January 23, 2012

Extension tube Canon EF25 II (review)

An alternative to getting a macro lens is extension tubes that you connect between the camera and the lens. There are many different brands and models. The reason why I chose to buy a Canon tube is because at the time I felt that it was the right thing to do. I haven't regretted it but in all fairness I probably wouldn't have regretted getting another brand either.

The reason why I chose to get a 25mm and not a 12mm was because I felt that the 25mm would work better with my other equipment. Along with my Canon EF 50mm f/1.8 II it produces great close-ups like this one of my nephew's eye. You can see my head and the camera in the reflection.

What the extension tube does is make the depth of field really short and shorten the closest focusing distance. It also makes it impossible to focus to infinity. As shown in this video. I'm using the extension tube with my 50mm lens to focus from nearest to infinity and back. Basically you change the focus distance from the near side to the far side of a penny while using the 50mm lens.


The shorter the focal length of the lens the closer you can get to the object. That means a 50mm lens is better than a 70mm lens which is better than a 200mm lens. The differences between those are shown in this video where I use the Canon EF 50mm f/1.8 II and the Canon EF 70-200mm f/4L.


There is also a limit to how close you can get. For example if I try to use the extension tube on my 30mm Sigma lens the infinity focusing distance will still be inside the front element of the lens which means it's useless.
When shooting macro most people wants to get a magnification of 1 of more. What that means is that if an object is 10mm in reality it will show up as 10mm on the sensor.
With the EF25 II extension tube you can get a magnification of 0.68 on the 50mm lens and 0.39 on the 70-200mm f/4L at the 70mm end. Magnifications are according to the table in the instructions that comes with the extension tube. According to those instructions you should be able to use it with a Canon EF 24mm f/2.8 lens and get a magnification of 1.22. Using a macro lens will get you even more magnification. The Canon EF-S 60mm f/2.8 Macro USM can get a magnification of up to 1.61. That means an object that's 10mm in reality is 16.1mm on the sensor.
As a comparison the table also has the EF12 II extension tube and with the 50mm lens I would only have gotten a magnification of 0.39 using that. So I'm guessing I made the right choice when I got the EF25 II.

Friday, January 20, 2012

Astrophotography

One of my biggest interest has always been astronomy. The emptiness of space is fascinating to me. Especially the night sky on a clear night is amazing to look at. The next step then is of course to try and take photos of it.
There are a few ways to do that. You can use a wide angle lens and get whole constellations in the photo. You can use a telephoto lens (for example all photos in this blog post is taken with my Canon EF 70-200mm f/4L lens and then I've cropped out a lot of the black surrounding the object I wanted) and get a single object. Or you can use a telescope to get even more magnification.

The moon is always a good place to start when trying to take photos of objects in the night sky. Not only does it change appearance every day, it's easy to see the "oceans" and craters with the naked eye. It's also the brightest object in the night sky.
Further away Venus is really bright. Our closest planet neighbour. It's the second brightest object in the night sky. Sometimes, like in this photo, you can see it in the west after sunset and sometimes you can see it in the east before sunrise. It's breathtaking to imagine that if Venus had had an atmosphere like the one we have here on Earth then there could've been life on Venus. It's almost the same size as Earth too so if there was no life we could've colonized it.
Then we have Jupiter. The massive gas giant. The third brightest object in the night sky. Seen here in a photo with its four largest moons. With my telescope I can actually see some of the bands and the red spot. However I have no equipment to attach my camera to the telescope so I can't take those kinds of photos... yet.
Occasionally the Moon passes close to one of the planets. On one such occasion I was able to take this photo. You can see the Moon in the upper right corner and the small dot in the lower left corner is Jupiter.
Of course it's not just in the night sky that you can see objects in the sky. I took this photo of the sun just minutes before sunset one day when it was a thick fog and cloudy.






I don't have that much chances to take good photos of constellations. Even though I have a wide angle lens I live in a small city. That means the sky is always polluted with light from the street lights and cars and stuff like that. I have a list of constellations that I do want to take photos of. Oh and I would love to take a photo of the Milky Way someday. When I do I'm sure you will see the photos here on this blog.

Wednesday, January 18, 2012

When I was in the Purgatory (short story)

Ok, so this blog was meant to be a way for me to post about my "adventures in photography". I.e. post photos that I take and write a bit about them and also post short reviews of photography stuff.
However, I was thinking "why limit myself so much, surely I can post other things here as well". Then I started looking through stuff I've written in the past and found a few short stories and poems and thought "hey, I can post those on the blog as well... at least some of them that aren't too... hm... how to put this... explicit".

The first one I will post is a short story that I wrote back in 2002. I was chatting with my close friend OlĂ­via and something she said gave me the inspiration I needed. I haven't spell checked or grammar checked it in any way so if you find anything that's incorrect let me know.

When I was in the Purgatory
The dark clouds came closer and the temperature dropped below 10°C. In the distant the chime of a church bell told everyone that it was getting late. It wouldn’t surprise anyone if it started to rain soon. It was just one of those nights.
There was a long queue on the sidewalk. Everybody in it was dressed for a costume party and they wanted to get in to the warmth of the new hip metal club called The Purgatory where they could party all night to the music of their favourite metal bands.
On the street corner stood an old man who was wearing a black outfit with a white collar and he muttered to himself, “If they only knew what the real purgatory was like they would never have been that eager to get in.” He thought for a few moments and then decided, “I have to get in and tell them what kind of powers they’re playing with”.
The old man pushed people out of his way while he was making his way through the crowd and when he was finally first in line he snuck inside without paying. He said reassuringly to himself, “My mission is more important than their money”.
The dj was playing the Iron Maiden song From here to eternity and the old man was trying to make his way through the crowd, who he thought were all dressed up as devils. He punched at least two young female devils and a few more male ones in their faces. Blood started running like a waterfall from one of the female’s nose.
He went past the bar where a young man dressed as a vampire tried to convince the bartender that he didn’t want anything with alcohol, just a glass of ice water. The bartender who was getting a little annoyed with the young man turned towards the old man and shouted, “Hey, reverent don’t you want some sacrilegious wine?” The old man didn’t even bother to look at the bartender.
When the old man finally reached the stage where a short, thin, young lady with long dark hair and a tight vampire costume was shouting to the dj, “Play something by Iced Earth!” he pulled out the power cord to the dj’s equipment and grabbed a megaphone from the table and turned towards the annoyed crowd. The young lady gave him a look that would have given him a heart attack if he had seen it.
Then he started to speak, “Listen up you little brats and listen carefully”. He took a deep breath to get a short break and then continued “Don’t you understand that one should not turn away from good? What you do here every night is sin”. He made another short break to make them think about this for a second and also to catch his breath, “If you don’t stop coming here and if you don’t stop listening to that which you call music you will soon meet each other in the real purgatory”. His voice changed and now he spoke as if he was preaching in a church, “When I was in the purgatory, I saw little devils and they were mean”.
It was dead silent. Everyone looked at each other and then simultaneously burst out in laughter. 10 seconds later they grabbed the old man threw him out the window. The young man dressed as a vampire finally convinced the bartender to give him the ice water. The dj reconnected the power cord and continued his set by playing the Iced Earth song Angels holocaust. And the young lady was in paradise.
An hour and a half earlier:
“Ok, bye.”
Damn that was the last person on my phone list. What should I do now? Why does everyone have kids? And why does everyone that doesn’t have kids have to be busy with other things? Don’t I have any friends that want to go out anymore? Not that I go out that much, I work most of the time and that keeps me indoors all day.
I really want to go out today. I guess I have to go by myself, not that I think it would be any fun though. Hmm, I could go down to that new metal club around the corner. Just to see what it’s like. What was it called again? Oh yeah, The Purgatory. That always makes me think about Iron Maiden or Dante. Wait a minute; didn’t I read something about it being a costume party there tonight? Let’s have a look in today’s paper. Yeah here it is, ‘Costume party tonight between 10pm and 05am only at The Purgatory’. Ok, it’s 9:30pm now and when I look out the window I can see people arriving. Looks like a lot of them are dressed up as devils. Maybe I have to hurry up a little if I’m going to have a chance of getting in.
I could use my old vampire outfit that I got for Halloween a couple of years ago. I don’t think I grown out of it yet, even if my belly keeps getting bigger and bigger. Ugh, that mirror tells me that I need to take care of something else too. I need to shave, really bad. Ok, so I need to shave, and I need to shower, and I need to get dressed, and I need to do it in less than 30 minutes. Good thing that I’m so pale from having to work indoors, otherwise I would’ve needed to put on makeup too.
Hmm, I don’t have any makeup. Why should I have makeup? Guys don’t even wear makeup if it’s not part of a costume that they wear to a party like this! If I had had a girlfriend I could’ve borrowed some makeup from her. Actually I feel like I really would want a girlfriend even if she won’t let me borrow her makeup. Damn it! I don’t need any makeup, why do I keep thinking about that instead of doing what I’m supposed to do. Right now, that would be finish shaving.
Ok, I’ve shaved, I’ve showered, and I have less then 10 minutes to get dressed and get down there. Now let’s find out if this outfit still fits me. The white shirt still fits, the black pants still fit, and the black vest still fits. I guess they all must have been too big for me when I got them. Oh, I almost forgot. I have to get the black cape with the red lining, and the black hat too. And I shouldn’t forget the black cane either.
One quick look in the mirror and then I have to leave. Good thing I’m not a real vampire, because if I had been one, I wouldn’t have noticed that I haven’t put my hair up in a ponytail yet. Teeth! I need my teeth, or maybe I should say my false teeth, I already have my real ones. Ok, just don’t panic. They have to be here somewhere. Here they are, and a perfect fit. It’s not that surprising really; I mean my teeth don’t grow at the same rate as my belly.
I hope the queue isn’t that long because it looks like it’s going to start raining any minute. There are a lot of people dressed up as devils here. Over there are some vampires too. I guess it’s the two types of costumes that people like the most. Well, the queue is longer than I wanted, but it’s not much I can do about that. Finally they’re opening the door. Hey, I know the door guy! I wonder if he’ll let me in now, or if I have to wait in line like the rest of the devils? Ha-ha, that was a good one; I’ll have to try to remember that joke for later.
Finally I’m inside, good thing I knew that guy so that I didn’t have to wait too long in line. Now lets try to get some ice water from the bar; it always seems to be a problem getting that from a “real” bartender. Wow, there are a lot of people here. It’s really hard to get through the crowd, but at least the music is nice. Ac/dc’s song Highway to hell is always a good party song. Oh, lots of pretty girls here too. Maybe I can go talk to some of them later. Ok, now I only have to get the bartender’s attention.
“Hey, can I get a glass of ice water? What do you mean ‘what kind of alcohol is that?’ It’s plain water with pieces of ice in it.”
Hmm… the girl that just shouted something to the dj looks very nice; maybe I’ll go over and talk to her after I’ve got my ice water. That’s one weird man. How the hell can you come to a club like this dressed as a priest? And how the hell does he think anyone would listen to that crap in a place like this? At least I got my glass of ice water now.

Monday, January 16, 2012

Samyang 14mm F2.8 ED AS IF UMC review

I've had this lens for a few months now but haven't really used it much. So today when I was bored I decided to take my Canon EOS 550D and this lens for a walk and test it out. The result of that walk can be seen in this video:


So now onto the review.
The manual focus is hard to use. Not just because it's a wide angle lens but more so because the distance scale on the lens is way off. The scale goes from 28cm to 3m and then infinity. My lens has infinity somewhere between 70cm and 1m. However if you use live view and zoom in to 10x it's fairly easy to find something far off in the distance to focus on. As long as it's a stationary object it shouldn't be a problem. When you do get the focus right it's very decent photos.
It does have barrel distortion (as seen in the first photo in the video), but other than that I haven't seen anything wrong.
I actually bought this lens to have a wide angle lens so I could photograph stars and possibly make time lapse videos. After about six months I still haven't had a chance to test it with stars. The alternative to buying this lens would've been to buy a lens with autofocus for a lot more money. So all in all I guess I can't complain too much.
In conclusion:
If you rely on autofocus you should not get this lens. It's manual focus only.
If you have more money than I have you could buy a wide angle zoom lens and get close to the 14mm with autofocus.
I will probably not use this lens much. If I get a chance to photograph stars then yes, but other than that I will most likely use my Sigma 30mm f1.4 that's on my camera almost all the time.