Thursday, April 28, 2011

Getting Directional Light Using Your Popup Flash

Ever wondered if you can get good quality directional light from your DSLR's popup flash just like the big boys with external speedlites do? This is what we'll try to find today. Hit the jump for the details.

DISCLAIMER: If you feel this post is hastily made, then you're probably correct, I had only one hour to prepare the images and write the post because of time constraints, so excuse me, I will be revisiting this topic later on with more finesse.

Ever since I bought my first speedlite I wanted a Sto-Fen Omni Bounce diffuser, I had almost zero lighting knowledge back then and I thought this was how everyone used their external flash, but since we don't have great camera accessories shops in Egypt, all I was able to find was this strange looking thing:

Excuse the lousy quality of the pictures but I really had no time (available light, handheld, ISO 1600), anyway, as you can see, this diffuser has a translucent white material at the top part, the sides and the front part, while the back part which looks black from the outside is lined with a bumpy reflective silver material from the inside. I think I bought this contraption for less than $6, and I also think it is supposed to fit on the speedlite's head some way or another, but I was never able to find any use for it with my flashes and it sat gathering dust for a long time.

Then one day I had the idea of using it on my camera's popup flash to bounce light of walls, can it work? Does the popup flash have enough power to get through the diffusing material, bounce from the wall and back to the subject and still give acceptable exposure? I know that new sensors now can deal with ISO 1600 with almost no noise, but will this be enough?

I think my camera's popup flash  guide number is 13 or something, while the speedlites have guide numbers of 40 and more, but even then, I remember that in several situations my speedlite didn't need to use full power to successfully bounce and give me a good exposure. So to try this idea I started off with a high shutter speed to kill the ambient and see how the flash did on it's own, I even started with ISO 400 to challenge the flash even more. I will be using f/2.8 aperture throughout the post, needless to say, this whole article is talking about indoor shooting.

Base Exposure - f/2.8, 1/250 sec, ISO 400

Direct Flash - f/2.8, 1/250 sec, ISO 400
I forgot how ugly direct flash looks, I left that years ago when I sold my point & shoot, and no matter what I tried to do with the white balance I was never able to get any better results.

Directional Popup Flash - f/2.8, 1/250 sec, ISO 400
As you can see here, the picture looks way better than direct flash alone, I put the diffuser thing over my popup flash with the reflective material facing almost towards me but an angle to reflect on my right side. I also put my hand in front of the flash to prevent any stray direct flash from reaching my subject, but as you can see from the catch lights I was not 100% successful.

Directional Popup Flash - f/2.8, 1/250 sec, ISO 800
I was not getting enough light from the flash, so I pumped the ISO to 800 and the result looked even better. Next I wanted to try getting some ambient light to work in my favor, remember that in bounce flash situations we don't always get light by using the flash alone, we use it to enhance the available light, so I dialed my shutter speed to 1/160 sec and kept the ISO at 800.

Base Exposure - f/2.8, 1/160 sec, ISO 800

Directional Popup Flash - f/2.8, 1/160 sec, ISO 800
You can see even better results with the ambient light (fluorescent lamps) contributing to the exposure, and I was able to shield the direct flash with my hand better in this one.

You might be wondering by now why go through this hassle and not shoot available light directly, two reasons, first, for the sake of experimentation, I am a geek and I like to try things, and secondly, because it looks way better than overhead available light that throws ugly shadows, see for yourself.

Available Light Only

Popup Flash Diffused Light (and no, the difference is not in WB alone)
Anyway, to sum this up, I was very happy with the results and I will definitely return to this topic with more ideas, but because of the short time I have to end here, if you have any comments or ideas please share them, and excuse any typos, I didn't proof read this post.