I need help with this. I had a dream… Well, not so much as a dream, maybe a “It’d be cool to…”

I thought it’d be nice to discover new photos on flickr using your favorite photos and the people who also favorited those photos, and the favorite photos of those who also favorited my pictures. Still with me?

It’s actually a quite simple code (about 500 lines, check it on github: discovr), but it’s terribly slow. Some possible reasons:

• Way too much data. I’ve found people with around more than 18000 favorites, and there are photos with more than 2k fans. After limiting to 50 last favorites, the numbers are still creepy. Following from my personal favorites (366), I discovered 1268 users and 52632 photos
• Too complicated for an API. This is the kind of feature that wouldn’t be so hard to implement if you have access to the flickr database directly, but having to do so many requests adds a lot of time to the process.
• Inefficient library. I had to do some modifications to the flickr ruby library just to make it work, but it’s still quite inefficient in some cases. Want to know the url of a picture (knowing the picture id)? 4 (completely unnecessary) API calls
• My code is bad. OK, I know it’s ugly to start blaming everyone else. I know my code is not very good, as it’s a quick prototype. Still, I’m not sure if making my code/libraries better would be enough improvement given the network/api bottleneck

The simplified algorithm goes like this.

  # method from class User
  def similar_pictures
    similar = {}

    favorites.each do |favorite|
      favorite.favorited_by.each do |user|
        user.favorites.each do |v|
          similar[k] ||= {:weight => 0, :picture => v[:picture]}
          similar[k][:weight] += 1
        end
      end
    end

    similar.values.sort {|a,b| b[:weight]  a[:weight]}.select {|v| v[:weight] > 1}
  end

So I’ve created a github repository and uploaded the code: discovr at github. Feel free to clone, test and improve

Sorry for the title. Actually there is no overall “best camera”, “best laptop” or “best whatever”. It always depends on what you need. If you just need a compact camera to take some pictures of your family trips or your college parties, almost any camera will do the trick for a much lower price.

That said, if you are serious about learning photography you should probably get a DSLR. You can get a Nikon D40 for about $400 or a Canon Rebel XS (aka 1000D) for about $500. I own the older Nikon D50 and I love it. Most of the pictures in this website were taken with that camera. I would only upgrade to the Nikon D700 but the gain isn’t worth $3000 to me.

Then, why am I recommending the LX3? Simple. The only problem I have with my D50 (and any other DSLR for that matter) is the size. It’s not too big for a DSLR, but it’s not a gadget to carry everywhere.

So, if you want a portable camera which allows you to learn photography, the LX3 is for you. I won’t go too technical here, but let’s highlight some of the features

• 10 Megapixels (large enough for screen and print)
• Shoots in RAW
• It has manual exposure and manual focus modes, so you can learn all the basics
• And the automatic modes are really smart
• It’s actually a leica (in fact this one but with the lumix logo and $200 less in the price)
• Very good optics
• Shoots video in HD

If you want more details, read the full review at dpreview.

Some samples:

I added more contrast on this one, but the original was already amazing.

Macro focus works like a charm

Not actually a video, but a time-lapse. It has a hi-speed burst mode where it can take 3-megapixel stills at 6fps
http://vimeo.com/moogaloop.swf?clip_id=5595252&server=vimeo.com&show_title=1&show_byline=1&show_portrait=1&color=b1c800&fullscreen=1
Get a drink on Vimeo

Not mine, but shot with a LX3, although it seems to have gone through some good post-production
http://vimeo.com/moogaloop.swf?clip_id=2383305&server=vimeo.com&show_title=1&show_byline=1&show_portrait=1&color=b1c800&fullscreen=1
Words Don’t Mean The Same Thing To You… on Vimeo

If you like what you see, you can get the LX3 on Amazon for $567.99

Yesterday, the ebox and warp staff went to Alagon (25km from Zaragoza) to have a very nice BBQ, or should I say WBQ?

We had delicious food, drinks, music, a swimming pool and weather couldn’t be more perfect.

And also we ended up with a new guest in our home

View warpbacoa on flickr:

[flickrset id="72157618335689578" thumbnail="square"]

I finished 2008 with a great 10 day trip to New York. A beautiful city with a lot to do and see. I hope to go back some day. Meanwhile, we have pictures: New York

If you like this article, vote for its publishing at JPG Magazine: Candid shots

One of my favorite subjects in photography is people. Not people posing for the shot, but doing what they usually do.

The basic idea of candid photography is to make the photographer invisible in the pictures. I have some tips that might help to go stealth

1. Use Long Lens and Cropping

You should have some long lens at hand if you plan to take sneaky shots of people. But don’t try to take every picture at 200mm. Even with image stabilization, focusing can be quite difficult when people are moving.

You want to find balance here. I have a 6-megapixel camera so I can’t crop too much for JPG Magazine, but less resolution is usually fine for the web. I’ve been uploading pictures to Flickr resized to 1000px for a year.

2. Shoot from a Bar or Restaurant

Taking shots of people in the streets without being noticed can be difficult. Try a coffee with big windows and enjoy your pictures of unaware pedestrians. This is especially useful if the place is dark and the street is well lit.

3. Use High ISO

You want clear images, so you’ll have to use relatively fast shutter speeds. You also don’t want to use flash if you want to stay unnoticed. There isn’t much more to adjust, so push the ISO settings in your camera to 800 or 1600. Of course you will get some noise, but then you can try converting to B/W and see some magic happen.

Don’t obsess with quality. When you are taking pictures of moving subjects in low light conditions there’s no room for studio quality, so forget about it. This is all about capturing the moment, not every detail.

Also, you can bump the exposure afterwards in post processing. I’ve got some nice portraits that way that looked almost black at first.

4. Carry Your Camera Everywhere

You might be thinking about your camera’s weight. I know they can be heavy. I carry a DSLR with a heavy lens almost every day in my backpack. It might not be very comfortable, but sometimes it’s worth the pain. A few weeks ago, some friends called me to go to a free concert just after work. I had my camera with me and I got great pictures there. I might be starting my professional career because of this event.

Also, you can always carry a Point-and-Shoot in your pocket. They are getting really small lately.

5. See Boring Moments As Opportunities

I don’t like shopping: I find it really boring. But last time we went to Camden Market I just forgot about all the shops and used the whole afternoon to take pictures. There is a lot of human interaction in a place like this, and a lot of people. In the case of Camden there are weird people too, so you definitely can get great pictures.

6. Shoot in Museums

Museums are places where I love to shoot. You can find there every kind of people, they are often well lit and you can get great face expressions. Most people will be watching closely the exhibition, so only a few will even notice your presence.

This goes back to the last point. In our last trip to London we went to the British Museum, but I had already been there. So I tried not to complain and use the opportunity to take pictures of people.

7. Use Events in the Streets

If you happen to find someone singing in the street, some band playing, or any other kind of performance it’s a good idea to capture the show. But look around you: there will be people enjoying the moment, with great expressions in their faces to portrait.

8. Try Black and White

Black and white is not a thing of the past. Especially in low light conditions, when you have to push ISO to the maximum, noise can be a problem in color, but in B/W noise can give more emotion to the image. And with digital photography, you can always go back to color if you don’t like it.

9. Watch out for Kids

I’m sure you already knew this one. Cameras love kids. Try to find them in the streets. They are much better in groups, when they are playing. Look for the kid you have inside.

10. Take Pictures of Everything

This is one dirty trick, but it usually works. Take pictures of everything: people, furniture, plants, objects… If everybody sees you doing so they won’t find weird that you take some pictures of them (at least not so weird).

I realized this one in a conference. Since I was taking pictures of everyone -and everything- people just started to ignore me. The other dozen of photographers also helped with that.

Extra tip

As a bonus tip, when you are trying to do all the previous things, avoid having someone by your side taking a picture with flash. It has happened to me.

Remember, if you liked this article, vote for its publishing at JPG Magazine: Candid shots

Also, if you liked the pictures in the post check out my Strangers set on flickr.

This is the original picture in Aperture, with colors exactly like I wanted:

Now the same picture in Safari

And now for something completely different: Firefox

In this particular picture, I used saturation to give strength to the moment, only to find out Firefox decided to wash out my colors.

The technical story here is that our monitors can’t display every color, so we have color spaces, and Firefox ignores them. Good news is that color profiles are supported in the Firefox 3 beta, though not enabled by default. You’ll have to open about:config and switch the gfx.color_management.enabled variable to true.

Bad news is, that will only work for you. If you’re trying to show your pictures to the rest of the world, they won’t see the same colors.

To learn more about this:

• Color space
• sRGB
• Web Browser Color Management Tutorial
• Digital-Image Color Spaces
• Introduction to Colour Science

Easy to read and straight-forward, Understanding Exposure offers the basics of aperture, lighting and shutter speed, photography’s basic triumvirate, to beginning and intermediate photographers. The book is divided into these three topics, as well defining exposure, special techniques, and a discussion of film vs. digital. This is not a highly technical book and any technical points are well-written and easy to understand.

My question now is if any of you have this book and recommend it. Should I get it or it has nothing I can’t found reading photography blogs and forums?

So, after my last trip I went to eBay and got this awesome lens:

Some good features:

• It’s really fast focusing
• It’s very sharp (see example)
• It’s small and lightweight, perfect for travelling

Also, the fact that it’s not a zoom forces you to move around subjects and experiment, helping you to improve your creativity.

You can check my 50mm test set on flickr.

Also you can get it in PDF for free. I’ll wait before subscribing since the price for US ($24.99/year) seems to be ok, but outside US it’s $48.99, which I find a bit expensive for 6 issues.

Clave de Sol

Snow after work

I have only two pictures by now, but you can check it in my profile