Sunday, September 4, 2011
Wednesday, July 13, 2011
Monday, July 4, 2011
- I did not have an M42 body cap and
- the extension tube is made of metal, whereas pretty much all body caps are plastic -- this is a plus!
Saturday, February 19, 2011
Friday, January 7, 2011
Note: this one only really works in full resolution. Click for the full res image (hosted on deviantArt).
old modified strobe in my right hand. I found the harsh lighting, desaturation and steep, dark contrast very fitting. A more in-depth view of how I got such contrast and skin-details (with the regular kit lens) after the jump!
Tuesday, January 4, 2011
The directory structure is very simple, I've set it up as
with yyyy the year, mm the month and dd the day of the month.
After having done some editing in the current month on my laptop, I wanted to sync it to my desktop.
I have a small script that uses rsync to synchronize the current working directory from my laptop to my desktop. I had deleted some bad photo's and obviously wanted them removed from the desktop as well. So I gave the script the --delete flag, which it handed over to rsync.
I ran the script and was greeted by screenfulls of lines saying deleted xxx or yyy. Hmm, I didn't delete that much pictures. I glance at the files that are being deleted, hmm, wait a minute, those aren't the right ... AAAAAH!
FUUUUUCK! I'm bashing CTRL-C for my life here! Finally it kills itself and gives me a shell prompt. I look at the current working directory:
That should of course have been
And as I said, I don't have a full mirror of all the photos on my laptop (not enough hard disk space there), so it started pruning all the older ones from my desktop. Ouch.
I've shut down the desktop asap and haven't booted it since. I'm probably going to try my luck with extundelete after the exams. Fingers crossed.
TL;DR Be careful with the --delete flag in rsync. It will fuck you up sooner or later!
Friday, December 24, 2010
The principle of single turn coils in a nutshell: you dump a whole lot of energy from a capacitor bank in a (single turn) coil. Once you get a few kiloAmperes flowing, you get a pretty high magnetic field, but the coil also endures intense magnetic stresses and a lot of Joule heating. Ultimatly the coil snaps after the peak field is reached and the vaporized metal turns into a nice plasma. The remains of the coil fly off outwards, keeping the sample intact.
I photographed the plasma and pieces flying off with a long exposure in a dark room. I was slightly worried about frying the sensor, as there is a lot of high energy UV light coming from the plasma. I actually stacked on two UV filters just for some peace of mind. I was still constantly checking the sensor during the first few images.
This is the best picture, it's an aluminium foil completely flying to pieces on our little testing apparatus (Click for deviantArt page where you can see the full resolution version)
This was done as a long exposure in a dark room with a 250mm lens stopped down to f/11 on ISO 100. It was one of the first photos I shot, I did some f/32 shots at first (to protect sensor), but those coil shots were less bright, so I opened up the aperture. Then this one blew up much brighter then before and kind of took me by surprise. The sensor is still OK though!
These pulses can reach about 2T, hence the catchy title 'Two Tesla Plasma' (go ahead, say that out loud. It has a nice ring to it, right?)
I also tried to get a 3D image by using a second camera from a friend of mine. Click the image below to see the effect (WARNING: I can NOT be held responsible for possible epilectic seizures)
The parallax looks a bit odd because both images were shot at 250mm on a cropped sensor. Using a focal lengtch that matches the human eye more closely would probably have made the effect much better, but I'm not too fond of getting the cameras that close to the glowing metal pieces flying everywhere.
So, everyone go and study physics: where you can blow stuff up and get pretty pictures -- for science!
[Edit] For those interested in more info, you can skim through the paper hosted at github (Don't mind the bleek results, we had some problems and serious time constraints).