02/24/13

DIY Water Balloon Photography Tutorial

One of the interesting techniques I hadn’t still tried until now was to capture an exploding water balloon just in the moment the plastic breaks, but the water still has the shape of a balloon. I didn’t want to invest any money in laser barriers or something similar, so I built a very simple mechanism that wouldn’t give me the perfect timing but maybe an acceptable approach.

Materials I used:

  • 2 sewing needles
  • A pice of plastic of about 20cm of length to build the lever.
  • 3 meter camera cable (for ease, depending on camera position)
  • A plastic washbowl
  • A small flash with wireless remote
  • A bag of small water balloons
  • A hot glue gun if possible (or just glue)
  • A tripod to hold the mechanism and water balloon, and another to hold the camera.
  • A mop!

Camera and flash settings:

  • Shutter of 1/100 or similar is enough, because we’ll illuminate the water balloon with the small flash only.
  • I recommend using an apperture of f/8 or narrower, because sometimes water goes in many directions and this way we’ll get more dof.
  • For the tests the flash was at 0.5m approx, at 1/64 of power. I recommend using the lowest power if possible to get a more sharp result.
  • Camera focus must be set to manual and I also recommend to adjust the frame for each photo since the size of the water balloons is not always the same.

Shutter trigger construction:

About the shutter trigger, my Canon 5D MKII uses an N3 connector, so I cut an old shutter cable to build the new one. It has three wires (Ground, Shutter, Focus) that will allow us to make a photo by doing a short circuit between Shutter and Ground wires. I’ve marked with a green dot the two necessary pins in the photo of the N3 connector. It’s not necessary to use the Focus wire since the camera will be in manual focus.

To build the other side of the wire, I welded each wire (Shutter, Ground) to a needle. Then I used the hot glue gun to attach the needles to a long piece of plastic with a little inclination so that if the needles touch a rigid surface they will touch each other. My initial idea was that the water of the balloon would short circuit the two wires, but at practice it didn’t result in my case, so with a little inclination in the needles they also touched each other when breaking the water balloon.

To hold the lever I used the materials I had at home, but it’s possible to hold it in many other (and better) ways.

Once the setup is mounted, a water balloon is hold with a string in front of the lever so that when the lever is released it will break the balloon and the needles will also touch each other to activate the camera shutter and make the photo, so the only thing we have to do is hold the lever in a higher position and release it to make each photo.

Photos of the parts and results:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Video of the mechanism in action:

As you can see the results are quite different between each other, because the timing was a little unpredictable. There are a lot of ways to improve this first test, trying to anticipate the explosion by placing the shutter cables in another place in the lever or changing the way the wires touch each other.

Opinions and questions welcomed ;)

08/24/11

Tutorial: Realistic HDRs with Photomatix

In the last years I’ve seen a lot of people abusing of this technique (me too at the beginning), creating irreal, oversaturated and noisy captures, usually made with Photmatix. I think that Photmatix is a very nice software but keeping always in mind its weaknesses, otherwise it’s easy to get fatal results, so that’s why I wanted to share some tips and personal recommendations about how to get slightly more realistic results with this program.

Not every scene will be better in HDR (High dynamic range), this technique is appropiate when the scene we’re capturing has some very dark or very bright parts (completely black or white parts). Sometimes our eyes can see these differences properly, but the camera’s sensor has less dynamic range than our eyes so some information will be lost. For example, a very bright sky but with dark shadows on the ground is a typical situation. But even in this kind of situations, it’s good to ask yourself which result do you prefer, getting all parts of the photo correctly exposed, or take advantage of this contrasted lights and get just the silhouettes of the mountains. In that case it wouldn’t be necessary to make an HDR.

For this tutorial I’ll suppose you know how to use the basic features of Photomatix, to get at least “ugly” results.

Before starting with the photomatix options, it’s important to say that to get a good result, it’s very important to start with a good set of photos. The typical bracketing option of the DSLRs usually offers +1, 0 and -1 steps between each of the three photos it does. I always to it manually, because I think sometimes it’s not enough with three photos, and sometimes I prefer doing the photos with less than 1 step between each one. I usually do 2/3 of a step between each one. I also start with the brightest frame, then I take several shots, lowering each time 2/3 of a step, and I do the necessary photos until I think it’s dark enough and it’s useless to make more photos. I recommend that if you can do more than three, do it, and once processing, you can choose if it will look better with three or more captures. The only two possible disadvantages of not using bracketing is that you may move slightly the camera while changing the exposure of each shot, and the other disadvantage is that you need to be quick if you’re capturing a landscape with clouds, because if it tooks you more than some seconds the clouds won’t be at the same place on the next photos. This last thing is something you need to avoid, because once in photomatix, when aligning the whole set of captures, it’s possible that the program uses the clouds to align instead of your main subject!


Also, photomatix allows you to make Pseudo-HDRs with only one RAW file, and then it does the bracketing, but this way the results tend to be much more noisy, so I recommend doing always separate captures, except when the scene has motion, in which case it wouldn’t be possible. My recommendations are the same for both methods, but my example will be with only one photo (on the right, 6″ exposure, ISO 400 and f/4.5). I tried to make a proper exposure because I just had the opportunity to do one photo (I was the last visitor that day).

Now these are the controls which I consider more important:

  • Strength: The name says it clearly, the more strength, more irreal and contrasted will be the result. I think that what it does is to let the darker captures manifest more than the bright ones. If you really want a real result, keep it low. This will also help to improve the noise of the photo. If lowering this parameter the photo becomes too bright, you can control this using the next parameters, do not increase again the strength just to get it nice exposed!

 

  • Color saturation: I personally like it a little saturated, this way I have the enough color information on the photo to increase or decrease it later in Lightroom. Even when I know that the photo will be in b/w I save it in color, maybe I realise later that it could be more interesting in color.

 

  • Luminosity: One of the most important controls, keep it as low as you can, it’s true that will be hard to get all the parts of the photo correctly exposed, but believe me, if you start with a good set of captures with slight exposure differences, this won’t be a problem. The error a lot of people does is to put a lot of luminosity, when I see these captures I think “oh, he used Photomatix”, because it’s very typical to get blurry and false results with this control, so keep it low!

 

  • Light Smoothing: One of the controls people thinks is cool at the beginning but also betrays that you used Photomatix. Depending on the position, different parts of the photo will be nice exposed, but as you get more parts good exposed, is when you get irreal results again. In very low or low, equals science fiction, so try to use always high or very high. Very high is the smoothest choice, which will expose especially the center part of the photo. Sometimes is better the High option, which affects to the whole photo and depending on the capture can give better results, its your choice to see which one fits better with your photo, but I don’t recommend using a lower value of this control.

 

  • Microcontrast: Another important control, in combination with Luminosity, affects dramatically to the overall result, and I recommend to move it as high as you can. If you used a very low Luminosity you can decrease a little this value to get a little more of light if you need it, but you’ll also lose contrast.

 

  • The White Point and Black Point is a personal choice, using a higher black point will give darker results, which you can compensate with the white point, but any radical choice will result in an irreal result or more noise, or both.

 

  • Temperature: I use the same for most of my captures. If you don’t touch the temperature control, after processing several photos you can observe that it give kind of orange/yellow tone to all the photos, so to compensate that, I use a lower temperature (usually -3 or -4) to get the correct color.

 

  • Micro-smoothing: This control can give more textures and details to your photo when it has a low value (typically 2), and you can even get more details with 1 or 0, but with this slight changes the noise of the photo can dramatically increase, so again, if you want real results, try to use a value greater than 2, there’s no problem if you move it very high.

There are some other controls but I think they’re less important, you can even leave them by default, but one thing I noticed is that’s complicated to get sharp results using only Photomatix. I usually export the file to tiff format and import it in Oloneo software (http://www.oloneo.com), just to increase the sharpness of the result, otherwise it may look dreamy or even blurry.

 

I hope this was helpful to somebody, below there’s the resulting image processed with Photomatix, then Oloneo for increase sharpness, and then imported to Lightroom to do some slight changes of contrast and temperature. In fact
this photo is not very realistic, but what I wanted was to explain how to get more real results.

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