That’s right – you will be learning today how to create a black background by using your flash. It kind of sounds counter-intuitive, but it really works! Trust me! So, here’s what happens…you take a picture of some knick-knack or other object, or even a person and that background it just…bleh! Take a look:
Throughout this tutorial, the metadata (EXIF) is in the upper right corner of each image, so note what details change in each and look at the outcome of that change on each image – this will help drastically in your understanding of manual flash control. Having said that, let’s take a look at our first image. While the chair and everything else in the dining room is out of focus, it still is pretty obvious that we’ve not put a lot of thought into the image. There’s certainly nothing too compelling about it for me (but you may be a huge fan of Mariachi men, who knows…). So, we want to go from the shot above to a shot like this:
It’s pretty easy, but it does require doing something that you might not be used to…switching your flash from it’s automatic mode (also known as ETTL) to manual mode. It makes sense when you think about it – we switch our cameras to manual mode to control aperture, ISO, and shutter speed to get better output, so why wouldn’t you get better output controls over your flash by taking it into manual mode? Let’s dive in!
To start things off, I shot this little guy with ETTL (which stands for Electronic Through The Lens) - letting the flash define the output for me, just to see how close it could get to what I wanted. So, let’s take a look and see how smart the flash is:
Hmmm, looks like these built in flashes aren’t so smart after all. The dude is almost complete blown out with no detail, the table is oddly lit, and don’t even get me started on the chair in the background. ETTL is not my friend here, so let’s switch it to manual mode so I can tell the flash what to do! For now, all we’ll do is change to manual, leaving the default power settings of FULL in place. Here’s the results:
Yeah, still pretty nasty, so we need to start dropping how much light is being pushed out of the flash pretty substantially. Well, since flash power goes in multiples of 2, our next step down would be at one-half power (1/1 = 1, so half of that is 1/2). If you know anything about flash yet, you’ll probably know what the results will look like, but bear with me here for a minute, while the demo portion continues:
It’s getting better, but minimally so. Did you see how the background changed just a little bit? We have a long way to go to get this exactly where we want, but let’s not get ahead of ourselves. Think about it for a second, we’re cutting the amount of light by one-half each time we dial it down again. So, from full power to 1/2, our next stop down is to 1/4th of what we started at. Thankfully, the dial on our 580EX II tells us that, so it’s easy enough to see the adjustment there. But what impact will it have on our picture? Let’s take a look:
Wow, look at that! We’ve cut our light from full power to 1/4th of what it was originally. Think of this like going from 32 lightbulbs down to 8 lightbulbs in a scene. At some point light becomes “white”, and it takes a few degrees to dial things under control. Let’s see what happens when we dial things down to 4 lightbulbs in the scene (now we will be at 1/8th power):
Well, look at that. The chair actually is getting some nice light to it right now…and that’s about four feet behind our subject. What does this tell you about light? As it stretches further away from the subjeect, the amount of light it throws drops off pretty sharply, because our Mariachi guy is still pretty overlit. We can see a little detail in the shadow behind his arm, but barely any. (Quick pet peeve reveal: This means using your built in camera phone flash at a football game is pretty much useless, right? No flash can throw light that far!) Back on topic though, this does mean that we need to drop our light power substantially more to get to a completely black background. So, for easy demonstration, let’s just show the rest of the steps in sequence until we reach our goal (or lowest flash output, whichever comes first!):
The above is at 1/16th power (2 lightbulbs)…
1/32nd power (1 lightbulb only!)
We’re getting close @ 1/64th power – now we’re reducing the wattage of our lightbulb too in laymans terms!)…if you saw the EXIF at the beginning you should know what’s next, right?
We got there, finally! But, notice (now that your eyes are more attuned to the changes throughout the image that our background isn’t really completely black. To get that far, we need to exert even more control over our flash than what I did here. Of course, it would also have helped if I had removed the other placemat from the table, as you can still see the white line from the edge of that in the frame. The top surface of that is also likely reflecting some light upward, so who knows, this scene may have already gone completely black in the background with that added change. I’m not sure though, because I did have a white reflector off-camera to the left the whole time!
My little sneaky surprise here is that I was back-filling a little to add just a hint of light to his backside and you can see it when you look at a comparison shot there. The EXIF data doesn’t change from the final shot, but here’s a “before” when I took the reflector out of the scene:
Pretty cool, eh? See what you can do when you take your flash off auto? You can play! I could have really dialed this in and made it a black background if I had done two more things:
1. Used a light stand and an umbrella as a shoot through (which you already should know how to do from here)
2. Used a litle snoot effect to really point that light in a focused way. (If you browse the archives, I talk about snoots here and here).
Hopefully though, you get the point that you can really impact your photos by simply jumping into manual flash! For those who are already experimenting with flash – what would you have done to really make the scene pop some more? I know of at least 3 additional techniques that could impact it further, but will let readers chime in with their own thoughts rather than spoil it here. Keep on shooting, and don’t be afraid of flash!