Wednesday, June 20, 2012

Flashing your subjects

Sorry for the wall of text, there are 2 photo examples in there, i promise.
Also, someone mentioned that the images are not loading sometimes. Try refreshing the page, i've already contacted support for this. We'll see what they say.

Most people understand that it's for the best to have lots of light when taking a picture. After all - photography basically means to draw with light. What you actually need to do with light is to control it as much as possible, not just to have lots of it. Too much light may in fact ruin a picture if it is coming from the wrong angle. Ways of controlling the angle of light is your subject’s location, a reflector of sorts or to add a light source of your own, your camera’s flash. The flash is not just for adding light in low light situations, sometimes it may even ruin a night time photo while a daytime photo might be in need of a flash. Yeap, a daytime photo that most people wouldn’t think of using a flash (because you have the sun), may need some extra light coming from the right place. Camera sensors are not even close in behaviour when compared to our eyes. What you see, is not what the camera sees. Once someone realizes that, it will be easier to get the desired effect. And no, i won’t be going into serious flash photography where you use one or more flash units to light your subject and then another flash to light the background in a way you want. (It is though a really interesting subject, but that is not the point of this post.)

The first and most important use for a flash is of course fill flash, meaning to use the flash to add light to shadowy areas. That could very well be that friend of yours that you want to take a picture of, but is standing with the sun behind his back leaving you facing the sun. Sun blinds people but it blinds camera’s even more. That auto exposure and “limited” digital sensor kick in to lower the overall brightness of the scene to manageable levels and so the image ends up with a nice sky, but with everything else really really dark. What will you do if you can’t change your location? Use your flash of course. That’s why it’s there, it will try to fill in and brighten up the dark areas.

The fill flash can be done with any camera, compacts and dSLRs alike, it just needs a flash. The next two uses are easier with an external flash like the ones for dSLR cameras.

You can also use flash to simulate a softer, more natural light source. Swivel that head. Its got joints for a reason. As humans we are used for natural light to come from a big light source located far away, and the light hitting us from above, remember the cliche scenes from movies where they tell ghost stories with a flashlight shining from below? There's a reason some find it unsettling, the light is coming from an unnatural source. (Meaning we are used to seeing the shadows in a certain way.)
So turn that light source upwards and to the left or right and bounce the light on the ceiling and walls. The reason to do this is to give light a chance to diffuse and soften up a bit. Depending on the paint, the light may come down with a slightly different color and may even make the photo look warmer. (You can also use special gels to make the light coming from the flash match the ambient lighting more closely, but if you knew that, you wouldn’t be reading this anyway...) An added bonus for bouncing light on a wall is that your friends won’t want to hurt you for making their eyes bleed. A nice trick for nice results is to let light to come in from lets say a window from the left and then bounce light from a wall to your right to try and balance things out a bit. You may even play with the power of the flash to make things interesting with shadows. (Don’t forget, shadows are one of the things our brain uses to get info about a scene, especially if it is in 2D like a photo.) If you are using a compact camera and want to test bounce your flash, just use a piece of glossy photopaper in front of the flash, tilted 45 degrees towards the ceiling.

Just compare the two examples. On the first one the flash is aimed directly at the souvenirs, notice the harsh light and shadows. On the second one the flash head was aimed upwards. Light is softer and warmer because of the ceiling's paint. To make it seem as if the sun is at 45 degrees instead of noon, all one has to do is aim the flash head upwards and to the left or right. (Settings on both snaps are the same. Only the head's orientation was changed)

Another use for that rush of light is stopping action. It’s not as easy as putting the flash on 100% power and a fast shutter speed. Most probably your camera won’t be able to sync the flash with the shutter fast enough! Most consumer grade cameras have a flash sync of 200. Meaning it won’t be able to do its thing fast enough. The trick is in the flash. You see that bulb always flashes at the same exact power. What changes is the duration that the bulb fires. When you put the flash at 50% it is going to leave the bulb on longer than when putting it at 25% of output. That is what it really means. So if you put your flash at 100%, it is going to stay on longer, and so your moving subject will appear as if it has a trail. You could play with that setting and have a long or short trail from your subject, but if you want to freeze the action, then what you need to do is a bit opposite than what most people would think about. Up your ISO, select a slow shutter speed and for the flash’s power output, put it at around 1/32 of its power. Not half, not one eight. That 1/32 (or even 1/64 power) is going to be fast, making your effective shutter speed so fast that your camera can’t even think of reaching normally. Of course, with this trick, don’t expect to light up the whole scene. Just aim the flash head at what you want to “freeze”.

This snap was taken with a shutter as slow as 1.6secs. That's so slow you need a tripod. Yet, even with having the shutter open for more than a whole second, and just by holding the flash and manually triggering it when the cherries hit the water, the drops are clearly captured. Nothing blurred. (Yes i was throwing cherries in a glass of water. I know its not classy enough :P)

P.S. click the pic for a bigger view.
Oh and the f stop was f8, with the flash manually triggered at 1/32 of its power.

2 comments:

  1. Hi George! I just had an 'AH HAH!' moment when I read that what the camera sees is /not/ what the human eye sees. As someone who struggles to take even the simplest photo this was a revelation.

    So essentially to take good photos you almost have to see what the camera sees and then adjust stuff so the camera shot can approximate what you, the photographer are seeing... Right?

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    Replies
    1. You'll need to trust your camera's meter (if its an slr type) or the auto mode on a compact. Of course with compacts you have the extra help of the live feedback from the LCD, it shows exactly how the photo will come out like.
      Cameras are getting better and better but there are still limitations.
      After using your camera for sometime in various lighting conditions you eventually start to anticipate what the photo is going to come out like and may even adjust the settings beforehand.

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