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Wanted: meaningful digital camera metrics

2009-06-10

I just had a short discussion with @kalleboo on Twitter about digital camera sensors and the quality of their resulting photos. I took this a bit further by researching for a while on the web, and found some interesting facts.

Firstly, the resolution in megapixels (Mpx or MP) that is so widely used as a metric today, actually says very little about the quality of a digital camera. If we set aside lenses and craftsmanship (which of course affect quality) it’s still a lot more meaningful to compare image sensors than resolution. Megapixels are here to stay though, because they’re meaningful metrics. Had the image sensors had a more meaningful metric, this may have been a common way of referring to camera quality — as it should.

Digital camera (photo by topfer)

Digital camera (photo by topfer)

CCD (photo by precert)

CCD (photo by precert)

 

 

The camera’s lense takes in light in a circle with a certain diameter, and from the center of this circle, the image sensor crops a rectangle that becomes the photo. The image sensor is typically a CCD, though it could be a CMOS as well.

Differences between bigger, more expensive cameras and smaller, cheaper ones are plenty, but one is the sensor size. A compact camera and a DSLR that both have a 10 MP resolution do not produce the same results. Now, obviously optics weigh in, but aside from that, the DSLR is likely to have a much larger sensor, which makes it more light sensitive and thus its images get less noisy.

The metric used for image sensors today, the so-called type, hails from 50s TV camera tubes and is given in fractions of an inch. It actually corresponds to the imaging circle and doesn’t necessarily have anything to do with the size of the image sensor. Example sizes are 1/2.5″, 1/1.8″ or even 2/3″ which don’t exactly lend themselves well to comparison. Try it yourself — which is bigger: 1/1.8″ or 2/3″?

There is no fixed ratio between sensor size and imaging circle diameter, however the mean value is about 2:3. This means the metric is off by a lot, and we really need another one. How about the diagonal size of the actual sensor? And let’s do it in SI units instead of outdated imperial ones, so let’s use mm.

According to Digital Photography Review a type 1/3.6″ sensor, would be about 5.00 mm, 1/2.5″ about 7.18 mm, 2/3″ about 11.00 mm and 4/3″ about 22.50 mm. Why don’t we just designate them by that measurement? We can even round down to simplify. If an ad for a digital camera said “10 MP resolution, 5 mm CCD” and another “8 MP resolution, 11 mm CCD”, I’m pretty sure I would buy the second one, even though it had an inferior resolution.

But that’s not all. Consumer cameras ofter use a Bayer filter to split incoming light into base colors onto the CCD, whereas professional cameras can have three separate sensors with a prism diverting each base color onto its own sensor. This gives the expensive cameras a much better color resolution, and adds another metric — i.e. number of sensors.

If a camera had multiple sensors, it might be displayed as “12 MP resolution, 3 x 22.5 mm CCD”. Of course this could become a bit much for certain people, and they might ignore the sensor altogether. A simpler format might be just “10MP/5mm”, leaving out CCD/CMOS and number of sensors.

To conclude, I would love to see camera producers being bolder and challenging megapixels as the “people’s standard” metric. Regular people are easy to fool (digital zoom proves that) but couldn’t you give us the chance to choose for ourselves whether or not to disregard important information? Discussion is welcome through comments.

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Angst and rejuvenation

2009-05-28

Yesterday I had a thermodynamics/nuclear physics exam. It was a re-exam and I hadn’t tried it for a long time. To be honest I probably should have checked it out a bit earlier to find out that it was really extensive. I mean, the amount of information was just immense. Anyway, to make a long story short, I think that in order for it to have succeeded this time I’ll have to be lucky.

This was the start of a day that would be pretty crappy for the most part. When I drove down to Lund for the exam, the weather was crappy. When I sat inside writing, the sun shone in my eyes. When I left to drive home, the bad weather came back.

[qik url=”http://qik.com/video/1751891″%5D

I was scheduled to meet my fiancée in Elsinore, and would go there by taking my bike on the ferry. I was just going to make a quick pit stop at home to get a few things. When I got home, I was greeted by an electricity bill twice its usual size. I decided to stay home a bit more, to check out the electricity company’s site, to see why this might be. No luck &emdash; probably just because they recently switched to remote meters.

This extra browsing contributed to the fact that I was late to the ferry, but there was more to it. Getting the bike out, I noticed that a few spokes were lose. Quite a few, actually. I didn’t think much of it, but once on the bike, it started wobbling more and more. I was strapped for time to reach the ferry and really gave it my all to get there. I tasted blood! I got down there, the bike wobbling ever more, seeing the ferry standing still, lighting a slim hope of getting on it. Just as I got all the way there, it started inching away slowly, and I realized I had 20 minutes of waiting for the next one, while gasping for air like crazy.

Finally in Elsinore everything went fine, so that was a nice break, but the bike got more and more wobbly, and I had to get off and pull it alongside most of the way for fear of its total breakdown. I arranged to leave it at my parents’ house for my dad to try to fix it, and we got to talking about school and jobs and debts and adding onto everything else from that day, I was really starting to get depressed.

When I finally drove home to call it an evening, I was greeted by my fiancée, and every problem got blown away. It’s amazing how healing it can be to have someone’s complete, and unconditional love like that. She’s always amazingly comforting, and I owe all my happiness to her. Today is her birthday, and I woke her up with gifts and hot cocoa.

The bottom line is that almost anything can go wrong, but as long as you have someone who loves you it can never hurt you.

The (very personal) Eurovision aftermath

2009-05-17

Last year I boycotted the eurovision song contest, because I thought it had turned into shit. It wasn’t the first time.

I guess you’d say I should celebrate. That a Norwegian victory is a Scandinavian victory. I don’t see it that way.

I’m not even upset that Sweden didn’t get that many votes, because though I loved the song, I never saw it as a eurovision song. No, it’s a defeat partly because songs that were crap (IMHO) came out on top, some great songs got pushed way down, and because Sweden didn’t even send one lousy point to Denmark. I know you’re not supposed to vote 12 for friend countries just because they’re friends; but surely there should have been something? And if it’s something you actually like, then by all means vote it high! The Danish song was really good. Very radio friendly. To top it off, I think he was one of the few, if not the only one who looked genuine and humble. Most everyone else donned fake smiles and too small shirts. (Yes, I’m looking at you with the shirt thing, Greece.)

I also fail to see the apparent greatness of the Belarussian/Norwegian winner. Sure, the song was nice, but not nearly as good as many others. It was number 13 on my list if I remember correctly.

This brings me to another thing I don’t like, which is that everyone works for anyone. Nowadays most countries incorporate songwriters, stage performers or even singers from other countries than their own.
A majority of performers don’t even sing in their own language. What’s left to compete about?

This is of course a personal standpoint, but it shows that the majority of the people who vote, are not the people who like what I like. That reason alone should be enough for a boycott. I mean at most times during voting, the top 5 would have been in my bottom 10.

For the sake of comparison, my points would have been:

  • 1pt Finland
  • 2pt Turkey
  • 3pt Albania
  • 4pt Azerbaijan
  • 5pt Ukraine
  • 6pt Bosnia & Herzegovina
  • 7pt Moldova
  • 8pt Armenia
  • 10pt Estonia
  • 12pt Denmark

I guess some would say I contradict myself by not voting for Norway or Iceland, but my reasoning is that any Swede would like some neighboring country’s song, so that it evens out and they all get something.

Anyway, this was yet another whiny post, but maybe that’ll be a recurring theme. I’d like to end by congratulating Norway. Even though their song wasn’t me at all, I’m still happy for them. And maybe it’ll mean some better show hosts for next year.

It’s now 2:30 am. Goodnight.

Tagjacking/Trendjacking

2009-05-07

Today I stumbled upon something on Twitter that is probably old hat, but news to me. I’ll dub it tagjacking or possibly trendjacking.

The Twitter app I use on my PC is Twitzap which, among other things, provides channels for trending topics. One such topic was #RSG, and I had no idea what it stood for. Naturally I clicked the link to learn what it was all about.

Hoping to get informed quickly, which is probably my prime interest in Twitter, I expected to see brief explanations or at least some link that would get me started. I did not have any such luck.

What I saw was a lot of people asking what the topic was all about (understandable, but still overwhelming). Lots of people were poking fun at the topic, claiming different meanings for the abbreviation. Most importantly, there were several totally unrelated posts with links to random spam. Those posts contained the hashtag only because it was trending!

Checking out What The Trend didn’t help, as no one had yet explained the topic in question. Even now that it is filled in, one cannot help but wonder if it’s actually correct with so many differing accounts of its meaning.

Later today, I was watching War of The Worlds (commonly abbreviated WoTW) and used the hashtag #wotw in a few posts on Twitter. I later checked out a channel (search) for that tag, hoping to find more on War of The Worlds. The search didn’t yield much of a result, but I found that people used that tag for other things. This is yet another issue seeing that tags, often being short, can be used for several different things. How do you know which one applies to what you’re interested in? Do you replace a tag with something new if you find out that another meaning for it has become more popular?

Of course a lot of topics are self explanatory, but there will always be name collissions. Any network would be partly self-regulating, but maybe not enough, if spammers get through. What I’m wondering is: would it be possible for spammers to actually ‘break’ a tag, so that the original idea gets lost? I believe that would be a great loss to a social network. What do you think?

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Slow People

2009-05-05

Reader be warned that this will be a rant, to get a few things out of my system, or something to that effect. That said, read on. 😉

Me and my girlfriend were in the supermarket today, and an elderly couple decided to park their cart just inside the inner gates to read this week’s advertisements, making it difficult for us and people behind us to get in.

Naturally I got annoyed, and as we’d made our way past them, I muttered something to my girlfriend about “punching slow moving people in the back of the head”. That’s part of the name of a Facebook group, and obviously an overstatement. I said it in jest, of course, and to my girlfriend about the people at the entrance. However, the lady in front of us at that point seemed to overhear it and said something like “Maybe we should get out of the way” to someone she was there with.

My girlfriend got embarassed, and so did I at first, but then I thought “why should I?” I wasn’t talking to that lady, and if she decided to think so, that’s not on me. If only people would show the same common courtesy when walking, as a lot of car drivers (not enough, but still a lot) do, and pull over to the side before slowing down this sort of thing wouldn’t happen. Why should it be rude to comment on rude people?

My comment wasn’t at all directed at that lady, but seeing as she seemingly took it to heart, maybe it should have been. I mean, her and her buddy were blocking the way with their carts side by side, it just hadn’t yet become annoying at that point. Why do people think they’ve got no obligation at all to let people past them?

I’ve actually seen people put their shopping cart in the middle of an aisle broad enough that if the cart had been put to the side, another cart could even have passed by, to go to another part of the store and fetch something. :O Seriously!? I got to thinking that maybe some kind of signal (the pedestrian equivalent of a car horn) would be nice. 😛

In traffic, it’s almost the same thing. I think people should have their driver’s licenses retried at a certain age and/or that there should be some kind of mandate on how quickly a car has to get up to speed after a turn or stand-still.

It seems the traffic slowliness offenders generally consist of two types:

  • The people who themselves have all day to get where they’re going, and don’t really care whether other people do. They’ll gladly keep 30km/h (19mph) on a 50km/h (31mph) road indefinitely.
  • The people who have cars that are (or may be perceived as) expensive, and think that they have to take ten minutes to get up to 50km/h (31mph) lest their priced pets get ruined.

An observation I’ve made about those categories, is that the first one often equates to older women, and the second to older men. Really! Think about it…

People complain about the younger generation speeding, but do they ever remember that you’re taught in driving school to reach the road’s designated speed as quickly as possible, because failure to do so is equally dangerous?

Okay, I think I could ramble about stupid drivers all day, so I’d best not get started. 😛 Consider the rant officially over.

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Newly started blog

2009-05-01

I’m going to try (once again) to start a new blog. I know I’m not very good at finishing what I started, unless given specific deadlines and tasks; so what I will try to do, is to make it a target to get at least three blog posts per week. That seems managable, right?

I’m going to try using WordPress instead of my regular platform, Blogger. I’ve been told so many times about the professionalism and multi-functionality of WordPress, so I decided to give it a try. At the same time, I’ve been reading about personal branding, and how important it can be to register your user name before anyone else. I’ve come across several sites in the past, where someone else has already registered my preferred name, and it really pisses me off, to say the least. That’s why, lately, I’ve been joining sites like crazy. Not everyone of them has any content as of yet, but some do. Some are even more or less finished, as they’re basically aggregators for my content from other sites.

I’ve joined Tumblr and I’ve joined Chi.mp. I’ve joined LinkedIn, FriendFeed, Google Profiles and probably a whole lot of others I can’t even recall right now. To begin with I already used an awful lot of services, such as several photo sites (Flickr et al), Twitter, Facebook, plus a few instant messaging accounts. I only have one e-mail though. I’ve gotten my preferred username, aulin in most cases and jaulin when that’s not available. As aggregators go, I think they’re all nice, but I’ve got a special feeling about Chi.mp as being a very good looking and useful platform.

Because of Twitter’s 140 character limits, people have to find good URL shorteners, and I’ve tried a few so far, including snipurl, ow.ly, bit.ly and smub.it. Way back, I used snipurl when everyone else was using tinyurl, because it gave me the ability to choose a name for my link. Ow.ly has close ties to Twitter, and your account(s) via Hootsuite, and a hootlet which lets you post stuff to Twitter in a jiffy, which is really nice. They also have click-through statistics. The downside though, is that some people despise top frames, and ow.ly uses one of those. It also makes it difficult to open their links in a mobile browser. So I tried bit.ly. They’ve got pretty extensive statistics, and optional custom names, as well as Twitter integration. I’ve recently switched to smub.it, since it’s so easy to use (just type smub.it/ before the URL you want to save) and because you can not only have custom link names, but you can remove a link and then reuse the link name. So if you made a mistake, or noticed a link has died, it can easily be fixed while retaining the old shorturl. I just wish they had more extensive statistics, since they as of now have only number of clicks per link.

Speaking of Twitter, it’s really become addictive, seeing as it’s grown a whole lot since I joined. When I joined, no one I knew was on it, and I didn’t care enough to try and find out how to use it on my own. With the March 2009 boom, a couple of friends joined and I found a couple that were already on there, and it started rolling from there. I think I’ve fallen into a pretty decent pattern recently, and at least started to learn how to fully take advantage of all that Twitter offers.

Well, I think that’ll be it for now. Hopefully I’ll get back to this blog often enough not to let it rot like the others before it.

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