Red Hat

In Relation To Off topic

In Relation To Off topic

Red Hat 4 Kids

Posted by    |       |    Tagged as Off topic Events

I am ending my day totally exhausted but happy. Today we organised Red Hat 4 Kids in the Red Hat France office.

Every year at Red Hat, we organise a Red Hat Week to celebrate our culture. And in good open source community way, each local office expresses how it pleases this event. This year, I proposed to do a Devoxx4Kids for the children of French Red Hatters.

Red Hat 4 Kids (aka a copy paste of Devoxx 4 Kids) initiates children from 6 to 12+ to the notion of programming. Sharing our knowledge to teach them what daddy or mummy does. Sounds cool.

Scratch workshop

I knew it was doable since the awesome Devoxx4Kids team has successfully declined these events around the world. But my engineering spider-senses told me it would be quite a humongous task. I was right but it’s one of those projects where you need to jump first and think later.

What did we do?

For the 6 to 10 years old boys and girls, we have done a Scratch workshop. Scratch is awesome, it has all the basics of programming: blocks, loops, conditions, events, event sharing, etc…​ Here, not need to prepare much, explain the basics and let the kids go (see below).

For the 10+ kids, we have done the Arduino workshop: programming electronics for the win :) We have reused the Devoxx4Kids one verbatim.

We were also lucky to have the Aldebaran team with us. So the kids moved up from the basics of programming to full Nao robot programming. Nao is a serious guest start and actually easier to program than Scratch :)

What are the challenges?

You need to prepare everything material wise

We installed a fresh Fedora 22 on all laptops to get everything set up the same: this really helped as we did not have to fight different environments. To be safe, we used ethernet and not WiFi: some WiFi routers don’t enjoy too many laptops at once.

Don’t go too long

For the 6-10 years old, they started to slowly drift after one hour. Don’t go over 1h30 per workshops and do breaks between them. For the 10+, they actullally went beyond our 1h30 and chose coding over cakes: success!

Limit the introduction and slides as much as possible

Developers don’t like slides. It turns out kids disregard them after 4 mins top. I had to cut the presentation quickly and instead…​

Do customized assistance

Show them by pair-kid-programming how to do the basic things and let them do what they want: help them achieve their goal: story, adventure, games etc…​ One grown up for one to two laptops, two kids per laptops. Max. They will be much more engaged.

Special thanks

It’s quite a special feeling to see a good chunk of the kids being that engaged, asking tougher and tougher questions over time and preferring coding to cakes.

I have many people to thank for this project. Hopefully I won’t forget too many of them:

  • the Devoxx4Kids team for putting their workshop in open source

  • Audrey and Arun from Devoxx4Kids for giving me customized advice and reassuring me along the way

  • the Red Hat French facilities team for saying yes to this project and putting up with all the material challenges (room size, power outlets, laptop hunt, mouse chasing, etc.)

  • the local Red Hat techies for gathering the hardware, installing the machines, testing everything and helping out during the workshops

  • last be not least, the Aldebaran team for being part of the fun

Nao in action

Just Fracking do it

Don’t think, do it. Go to http://devoxx4kids.org and start from their workshops.

Panasonic DMC-LX3

Posted by    |       |    Tagged as Off topic

I want to say something about the Panasonic DMC-LX3. I've never written a camera review before, but I'm so inspired by the fact that finally someone made a compact camera for people who actually know something about photography, that I want to do something to encourage this trend.

For the past 10 or 15 years, camera manufacturers have invested in one awesome technological leap - digital - and a bunch of verging-on-useless features that bamboozle new users and complicate usage for everyone. Here's a quick sampling of just some of the non-features of a typical compact camera:

  • face detection
  • baby mode
  • multi-point autofocus (for all those folks who do action photography with a compact camera)
  • in-camera image processing (useful for people who don't own computers)
  • 10x zoom (at f5.6, of course)
  • 15 megapixels (crammed onto a 1/1.7 inch sensor)

Some of these features are harmful because they actually guide the user to use the camera in exactly the wrong way. For example, multi-point autofocus is enabled by default, since it's apparently too difficult to teach users the correct way to take a photograph (first focus, then recompose). Others are harmful mainly because they distract the buyer's attention from what's really important in a camera.

I was so excited by the LX3 that I ordered one on Amazon before there were even any published reviews. How did I know to do this? Well, what most buyers of compact cameras don't know - and what even a lot of camera reviews tend to downplay - is that most of what matters in a camera can be expressed with exactly three numbers. Here they are, in approximate order of importance:

  • the f ratio
  • the focal length
  • the size of the sensor

The f number tells you how much light the lens is able to capture. The smaller, the better. Most really good photos are taken in low-ish light conditions, or of moving subjects. Photos taken of still subjects in the middle of the day are usually boring, with ugly colors. Therefore, the more light you can get, the better your photos will be. Most buyers of compact cameras don't even know what an f number is, and the salespeople don't tell them.

The focal length determines the field of view. Unfortunately, almost all compact cameras are equipped with zoom lenses. In theory, a zoom lens makes a camera more versatile by offering a range of different focal lengths. Compact cameras are marketed on the basis of how much zoom they have (the ratio between the shortest and longest focal length). But in practice, cameras with more zoom take worse photos. It's very difficult to manufacture a good lens with a low f ratio and high zoom ratio. My gorgeous professional 16-35 f/2.8L costs $1300 and has just 2.2x zoom. A compact camera that costs $500 and boasts 10x zoom does not have a good lens! Furthermore, these zoom lenses generally begin at a fairly long focal length, robbing you of all the beauty of wide-angle photographs. Of course, there's no right or best focal length - the right focal length depends upon the subject matter. But, for the type of photographs that I use a compact camera for, I need some decent wide angle.

The size of the sensor limits the ugly digital noise that appears especially in low light conditions. It does not help to simply pack more and more pixels into a tiny space - resolution is not only limited by the number of pixels, but also by digital noise. A compact camera with a 15 megapixel sensor does not take photographs remotely comparable in sharpness and depth to an entry level SLR with a 12 megapixel sensor. That's because the sensor in an SLR is much larger. And a fullframe SLR like my 12.8 megapixel 5D is a different experience again. Unfortunately, a compact camera, by definition features a fairly small sensor.

So why is the LX3 different?

  • f/2.0-2.8
  • 24-60mm (35mm equivalent)
  • 1/1.63-inch 10.1 megapixel sensor

By comparison, my previous compact camera (the best compact camera on the market when I bought it a year ago) was a Canon G9. I got a lot of use out of it this year on a motorcycle trip from San Francisco to Nicuragua, and I was just never very happy with it (unfortunately, there was no room on my bike for an SLR). The numbers tell the story:

  • f/2.8-4.8
  • 35-210mm
  • 1/1.7 inch 12.1 megapixel sensor

Compared to the G9, the LX3 captures twice as much light, offers much more potential for dramatic wide-angle photographs, but has much less zoom (my experience is that the G9 takes ugly photographs at full zoom). In practice, this means I can take photos that I simply would not be able to capture using the G9.

Some examples:

P1000127.JPG

P1000188.JPG

P1000188.JPG

P1000075.JPG

P1000132.JPG

P1000446.JPG

Please bear in mind that most of these photographs were taken at night, by a drunk Australian.

Of course, the LX3 will never replace my 5D/16-35L combo. Don't expect it to rival any SLR with a decent lens. But I'm never going to take my 5D clubbing with me. So I could never have taken the photos above with the 5D. I can bring the LX3 almost anywhere. Most importantly, this camera is fun. I hate to admit, but I actually enjoy it more than an SLR...

Please buy this camera, even if only to help make it commercially successful. I already bought one for each of my sisters for Christmas this year :-)

UPDATE: a couple more points about the LX3:

  • it's small, but jacket-pocket small, not trouser-pocket small
  • yes, the lens cap is irritating - especially when your friends get their fingerprints all over the lens reviewing photos - but that's a small price to pay for such a great lens
  • to my surprise, the ability to switch aspect ratio turns out to be more than just a silly gimmick - the native 16:9 aspect ration makes for some really interesting compositions
  • the screen is so super-bright and contrasty that sometimes I'm tricked into thinking that an underexposed shot is fine :-/
  • the images look great even after some pretty heavy post-processing which is unusual for a compact camera
  • I hate and despise flash photography, but the couple of times I tried it, the flash seemed to be very well-metered (unlike other compact cameras I've used, this flash doesn't totally drain all color and depth from the scene and make everyone with white skin look like ugly hags) and if that's not enough, there's even a hotshoe for an external flash
  • I would prefer a dial for fiddling aperture/exposure, but honestly the little joysticky thing seems to work just fine
  • the mode dial at the top of the camera should be stiffer, it often shifts coming in and out of my pocket
  • you have to enter the menus to change ISO, which is a major pain (but better than the stupid dial on the G9, which always got bumped coming in and out of the camera bag)
  • it looks way sexier than the Canons
back to top