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iPhone Battery

// July 3rd, 2009 // No Comments » // Teknologi

My iPhone is almost 2 years, and I’ve been starting to notice it’s declining battery performance. I’m leaving for vacation soon and it sucks having to look around all the time for a place to charge your mobile when traveling, so I decided to get a new one. Found a cheap replacement on ebay, about $5-6 including shipping from china.. It probably suck, but I want to get a better (larger capacity than original) later anyway – when I have time to look around and do some research.

Got the battery yesterday, and put it in today.. Opening an iPhone is a bitch! Apple sure made this hard..

Instructions for opening the iPhone.

The battery is also soldered to the mainboard, so you have to desolder the old wires before removing the old battery. And then solder the new one in place (watch out so you don’t short the red wire with the others – apparently this type of battery doesn’t handle that well..). The new battery seems good so far, it’s still at 100% after several hours, just waiting for it to go nuclear and blow up..

All hail the mighty Apple!

// June 17th, 2009 // No Comments » // Mac, Teknologi

Just a small blog post while my old iPhone is updating to the 3.0 software. Even though the title is a joke, I have to say that the iPhone is one of the tech gadgets that have given me more value for my money than anything else. I bought it almost two years ago for just over 2000 NOK (imported from the US), probably one of my cheapest mobiles ever. It’s been updated several times over those two years, and not only small fixes, it’s been getting major feature-updates regularly.. I don’t think any other cellphone company have continued to give their firmware new features two whole years after the release. The device itself feels almost as cutting edge still as it did two years ago (even though I miss things like 3g support, etc..). If I break my iPhone today, then there’s no doubt what I would buy tomorrow.. a new one (or more likely wait a week and get the 3G S).

If it only was more open.. and Apple wasn’t that asshat about their app store restrictions.. It would probably be the perfect cell phone.. But I hope Android gives it a run for it’s money (competition drives the market)

Pentax k-m / k2000

// May 9th, 2009 // 2 Comments » // Photography, Teknologi

Sorry Håvard, you can just skip this one, it doesn’t feature any arrows showing which direction electrons travel :p

I bought a new DSLR body not long ago, a pentax k-m. It’s a rather cheap 10MP entry-level dslr, going for as low as 3600 NOK new here in Norway – I gave around 2800 NOK for it in the UK. So, what can this “toy”-camera do? Most of what the bigger brothers k10d/k20d can do actually. Here are a few of my own experiences with it..

Pentax k-m with da 21mm limited on flickr (cdehaan):

What have they stripped from it’s much larger bigger brothers – k10d/k20d: Weather sealing (you can’t bring it with you into the shower like the k10d), size, weight, top lcd, selectable focus point (and the red dot focus indicator in the view-finder), front wheel, Tav and bulb mode, cable trigger, and probably a few other non-important things. Quite a few of these could easily have been left on and still kept the cost down if you ask me, especially things that are mostly in software.

Even though the camera is quite light, it still feels very solid – not as solid as the armored and sealed k10d (which probably could crush someones skull without getting a scratch), but much more solid than other cameras in the same class. The grip is also smaller, but I don’t find this a problem, especially with lighter lenses. I even manage to wield something like a DA*16-50, anything larger than this though is a bit uncomfortable and looks comical. This camera thrives on smaller primes, something like pentax’ limited series (pancakes) would rock. Normally I keep my FA50/1.4 on it.

So, how is it in use..? quite good actually! Even though it lacks some features, I don’t really miss them much – maybe with the exception of the front wheel (especially when shooting manually). The autofocus is quite fast for a pentax (probably the fastest of the family) and doesn’t hunt as much as my k10d. What I do miss though is the screen – it could just be a feeling – but I like the LCD on my k10d better than the k-m’s. It just doesn’t seem as good in daylight.

Ok, so what’s the image quality like? From iso 100-800 it’s quite good, and goes a bit downhill at 1600-3200. A sample taken at iso 200 can be seen below, this is using a DA* 16-50/2.8 lens. It might not be fair to display samples taken with a lens that costs twice as much as the camera itself, but I think it really shows that if you have a limited budget it’s better to put your cash on the optics than on the camera – unless you really need all the extra buttons and frills that comes with a more high-end house. Besides, a limited lens / prime will probably give you even more sharpness than this at a lower price.

1:1 crop of the above image:

Other cool points about about the k-m.. it features in-house shake reduction, you barely even get a lens with IS/VR from other brands for the same amount of money as this camera. It uses the k-mount, which means that you use k-mount lenses going back as far as the 1970s – and get shake reduction for them. Even older lenses (M42) can be used with an adapter. Battery-life is surprisingly good, it uses normal AA-cells, and the batteries that came with the camera lasted me many weeks (3-4) and well over 1000 shots. It has some sort of dynamic range function, which seems to give better details in the shadows, I haven’t really used this much, and no-one really seems to know what it actually does. It has a dust-removal system (shakes the sensor) and also a system for dust detection. It supports SDM, for lenses with built in focus-motor. Menu system is quite good, and if you are a beginner – a help button explains everything for you. This help button can be reconfigured to other things if you don’t need it. All buttons (except flash-up and af/mf) can be operated using the right-hand while holding it.

If it wasn’t for rather low high-iso performance and the crippled 5-point (non selectable) focus system, I think this camera would completely wipe the floor with the competitors in the same price class (it still does on many points). They are all very good, so it’s only small differences that count. The K-m has some really good sides, but they shouldn’t have crippled it as much as they did if they wanted it to be the best entry-level camera on as many fronts as possible.

But, of course, to quote sveinmb, “it sucks goatballs” – because it doesn’t say nikon or canon anywhere on the body :p

Shared RSS-items..

// May 2nd, 2009 // No Comments » // Teknologi

Håvard posted some time ago about sharing interesting RSS items. I think this is a really good idea, then other people with similar interests can act as a filter for you. I’ve started doing this myself, you can find it (and other peoples’) feeds here:

• Mine: http://feeds2.feedburner.com/stian/shared
• Håvard: http://feeds2.feedburner.com/hsorbo/shared
• Tor Håkon: http://www.google.com/reader/public/atom…….
• Thomas: http://www.google.com/reader/public/atom…….

Spotify – Missing songs..

// May 1st, 2009 // 2 Comments » // Bog-skinke, Tanker, Teknologi

I really like Spotify, and it’s currently my main source of music. There are a couple of problems though that’s keeping me from completely going to Spotify (and paying for it to avoid the ads).

So many of the artists I like are not on spotify – like Pink Floyd, Metallica, Beatles, Led Zeppelin, AC/DC, etc. etc.. But what’s even worse is the music that once were available to you, but got removed because of rights. Some music can’t be played in some countries. Lately I’ve had a feeling that my playlists were shrinking, and suddenly wanted to hear “Eagles – Hotel California” – a song that I’ve had in one of my playlists from the start. It wasn’t there..

Turned off “Hide unplayable tracks”.. and a bunch of red songs showed up.. Songs that once were available, that now are hidden from Norwegian Spotify listeners. After searching for replacements, about 5-10% of this particular playlist was still unplayable. Bah!

NRKbeta had a great post about this after the pirate bay trial: Congratulations – you just wet your pants .. They hit the nail on the head. People don’t get why they can play a song in one country just fine, but just across the border you can’t.. Or why you can’t buy TV-series on iTunes if you live outside the US, and so on.. Rights owners, record companies, MPAA, RIAA, etc, etc, needs to loosen up a bit. The Internet is global and it’s heavily integrated in our culture these days, country restrictions just creates obstacles for people – obstacles they don’t get why should be there. When you add other obstacles such as DRM, forced anti-piracy propganda on original DVDs/Blurays, etc, etc, it’s no wonder why pirating is so much easier, faster and better when they impose stupid restrictions like this.

And wrap up todays wail, here’s a funny video Håvard gave me – explaining IFPI’s anti-piracy strategy:

Link

London + viz stuff..

// April 17th, 2009 // No Comments » // Teknologi, UiB, visualization

Just came back from London, had a fun few days enjoying the low GBP value.. Weather was really nice too, relaxed in Hyde park under a (semi)-blue sky and 21C.

Now it’s back to school and work, currently doing some multimodal visualization. Here’s an example I’m working on, combining CT, MRI and PET of a monkey. Showing a slab of volume rendered CT (bones) and PET (brain activity) on top of a MRI slice..

Popcorn Hour

// April 5th, 2009 // No Comments » // Linux, Teknologi

The Popcorn Hour is a relatively small networked mediaplayer running linux. Out of the box it’s fanless, so the only source of noise is the added harddrive (it supports a SATA-drive or external USB drives), making it a good candidate for a quiet multimedia system. It can read most filesystems, but only has write-support for ext2/3. I put a 1 tb western digital green power drive in mine. On the output side it supports component, svideo, composite, hdmi 1.3a, analog and digital sound.

There are several ways to provide it with media, you can upload it via samba, ftp, nfs, etc.. etc.. stream it over the network from a variety of servers and shares, or simply plug it into your computer (it will act as a normal USB-disk). It’s available on the network when you suspend it, so you can upload files to it at all times. And the good thing is, it basically plays everything you throw at it, including 1080p h264 mkv files. Sound is outputted either as the original stream (ac3, dts, aac) or  as PCM over HDMI, and it works great with my receiver. It has a thriving community providing all sorts of cool hacks and the firmware people provide regular updates.

This could have been the holy grail of mediaplayers, but it has a few issues and annoyances. It’s not future proof, if a new format shows up, then there’s no guarantee that you can play it. The remote control sucks, you have to basically aim it directly at the unit for it to work (you can however use USB-input devices, so it would probably be possible to replace it, a keyboard works fine for example), maybe it would be possible to create an iPhone app to replace the remote. The user interface is slow and based on HTML. While being easy to customize, who decided it was a good idea to base a mediaplayer interface around a webbrowser?? The interfaces are quite static, no smooth transitions when moving around, and it’s noticeably slow and laggy. Some settings I want to customize (for example buffer size when streaming) isn’t possible.. If I could set the buffer size up to maybe 50 mb, then I could easily stream HD-media from my server at home.. It also no good for large music collections.

There are several custom user interfaces showing up, I haven’t really tried them out yet, but I suspect they are as slow as the original, but maybe more visually pleasing..

But all in all, it’s small, portable, very low noise, very hackable, plays as good as everything.. and if you can live with the slow interface it’s well worth the money. A full HTPC would probably be better, but this gives you like 95% of the features for 5% of the effort..

• Networked Media Tank Wiki
• Networked media Tank Forum

Illustrative Volume Rendering

// April 5th, 2009 // No Comments » // Teknologi, UiB

This semester I’ve been doing a bit of shader programming (GLSL), and have implemented a series of illustrative techniques for volume rendering. The goal was to simulate some of the techniques used by illustrators and apply them to volumetric data (such as a CT-scan).

The first is a CT-dataset rendered using a classic cartoon-shader, it also includes curvature-controlled contours:

Same dataset using gooch-shading, includes gooch-splashback and contours:

Last is a CT-scan of a gecko, using different contour techniques – curvature controlled for the edges, and a low exponent gradient curvature for a bit of shading near the edges.. Looks pretty close to something one might draw on a piece of paper.

Oh, and it’s all done in real time.. I love GPUs.. More of my illustravis stuff can be seen at: http://www.student.uib.no/~sei081/visualization/illust/

Norwegian online banks..

// July 1st, 2008 // No Comments » // Tanker, Teknologi

You should be able to afford something better than the cheapest SSL certificate when you’re a BANK, come on, get at least the wildcard one.. and preferably one with Extended Validation so that people get that fancy green validation line in modern browsers.. Cheap bastards..

Also, the two last days most of the manjor banks in Norway have had big problems with their net bank service. According to Norwegian newspapers this problem was caused by a piece of hardware malfunctioning at EDB Business Partner.. You’re the heart of Norwegian Internet banking and you have a single point of failure?? (if the newspapers are reporting this correctly.. who knows..).. But anyway, you should have multiple redundancies in every possible point of failure when doing something like this..

.. today’s little rant

Bergen 3D

// May 22nd, 2008 // No Comments » // Linux, UiB

I’ve spent some time working on a virtual 3d bergen as a part of INF251 (Computer Graphics) this semester. Basically what we did was to render the terrain based on a height map (a file containing a height value at every x,y position), modeled some buildings, added textures, spline based camera paths.. etc..

Mine was developed on linux and uses Glut, GLEW, GLM, DevIL, Vmath.. etc.. You can fly around in Bergen using FPS-style controls (WASD+RF/mouselook).

See my page over at the university for som larger screenshots and a movie..