Sunday, March 6, 2011

Tutorial: High Key & Low Key


Hello and welcome to another lighting tutorial, this time I am going to show you a very quick and simple way to get high and low key images like the ones you see above using only one or two speedlites. More details after the jump.

INTRODUCTION

This article should've been posted a couple of days ago, but I had a change of heart mid-way. The original idea was a high key tutorial about a product that I shot a while ago, but since this blog is about taking better family photos; I have dismissed my earlier idea (product photography) and started from scratch on taking head shots, then later on I decided to add a low key technique as a bonus.

DEFINITIONS: HIGH KEY vs LOW KEY

So, let's start with high key first, high key is a lighting technique where image is bright, has a low contrast ratio and almost devoid of shadows, this usually gives a light and a happy mood to the picture. One of the ways to get a high key image is to have a white seamless background, which we are going to discuss in a little while.

Low key is the opposite of high key, low key images feature a high contrast ratio and lots of shadows in the picture, they are very dramatic and moody. Low key lighting is usually used in movies to express horror scenes and dark mood, one piece of advice here, don't abuse this tutorial and take low key images of your spouse, females don't like non-flattering pictures, there, you've been warned.

Make sure you check this link for a more elaborate description and good examples on both lighting techniques: http://www.diyphotography.net/lighting-high-key-and-low-key

THE NITTY GRITTY: HIGH KEY

Today I am going to take the "white seamless background" route to get the image you saw at the top of the post, let's talk about details for a while, there are a LOT of techniques to achieve a similar image using flashes, here are some of them:
  • One way is to shoot your subject on a fairly uniform background (or even cluttered) then use a photo editing program to cut (mask) the background and replace it with pure white. This would be the hardest way to do it because masking hair is quite difficult and requires a lot of time even if you had a uniform background. Or you can use a plug-in to make it easier for you like our own Mic did here. But it would never be as easy as taking a perfectly fine photo that needs no further editing.
  • Another way is to use one speedlite on a light stand like Mic tried here, quite a brilliant result for just one speedlite!
  • Or you can go all complicated like this tutorial on phototuts, it is good but I don't believe it needs to be as complicated as they say it should, here's a quote from their tutorial: "Ideally you’ll have at least three lights, four if you’ve got the equipment. You’ll also need a seamless white backdrop of some kind". Don't get me wrong, this is a good and detailed tutorial but I don't believe you need all of this to get a similar image.
  • Finally, one of my favorite photographers has posted a detailed 5 part tutorial on high key images, it is pretty complicated and expensive, but Zack's high key images are the best I have EVER seen, and I can spot them a mile away.
So, what else can I add to all of the above techniques? I don't believe in rules and prerequisites, with some thought you can achieve what you want with a minimum of equipment and effort. You saw what Mic did above with just one speedlite and a corner.

As a start I put my subject in front of a rose colored wall and a bare flash on a stand to his right and took a base exposure, I wanted to achieve a couple of things with this picture.

  • First of all I wanted to know how well was my exposure, I have already determined my camera settings, aperture was f/8.0 to get enough depth of field (it could've been f/1.8 and I would still get my high key picture, numbers don't matter, it's all about what you want to achieve), ISO was at 200 to get clean files and use a low flash power which would allow faster recycle times, finally the shutter speed was 1/100 sec, the ambient was non-existent in the exposure so the actual exposure time is the flash duration.
  • The second thing was to show you the difference between hard light (this image with a bare flash) and a soft light (next image with an umbrella).
Here's how the photo came out, notice the edge in the wall behind our subject, I intended for it to be there to show you how I can easily overcome it during the process.

Bare flash, subject right - Click to see a larger version

Next, I used an umbrella to soften the shadows and get a less dramatic image, I increased the flash power a bit to compensate for the light loss through the umbrella, here's how the setup looked like.

Pull back shot, umbrella used this time - Click to see a larger version

Notice the speedlite on the subject left, it doesn't add to the exposure, instead I was using a studio flash that can only be triggered optically, so I used a Canon 580EX (triggered wirelessly) firing away from my subject.

I adjusted the flash power until I got the desired exposure, I judged my exposure using the histogram, here's the resulting picture.

Shoot through umbrella - Click to see a larger version

You can still see that the background is far from white, this is the next step, now that I have my subject exposed correctly and his distance fixed from the umbrella, it is time to turn that background to white. I added a 580EX speedlite pointed at the wall behind my subject, I started with 1/4 power since it was close to the wall and zoomed the head all the way out to 24mm to cover as much of the wall behind my subject as I can.

What we are trying to do is to get the wall to become completely white (i.e. blown out), this can be confirmed with the blinking highlights on the camera's LCD, I am confident that my subject is exposed correctly, this is what we did in the first part, so once I see my background blinking I know that it is pure white.

Final setup, pull back - Click to see a larger version

As you can see in the pull back shot above, the new light on the background turned it completely white, even the edge in the wall has disappeared, I'd like to use David Hobby's expression here, "I nuked the wall". This is how we get the final picture shown below.

Final result - Click to see a larger version

If you check the EXIF data, the time between the first shot with the bare flash and the final result is 10 minutes, this is how quick and easy this method is. Here are a few tips that I've learned through experimentation:
  • If you look at the subject's left side of the face there is a rim light, this is caused by an intentional spill of the flash pointing at the wall, if you don't want it you could flag the flash by a piece of cardboard.
  • You wouldn't want to use a lot of flash power on the wall behind your subject, if you do so you will get strong reflections from the wall that would cause halos around the subject.
  • Sometimes your speedlite wouldn't cover the whole area behind your subject, don't worry, just make sure that the areas around your subject are blown out, the rest can be dealt with in adobe camera raw using the adjustment brush, use it and turn the exposure to +4 and the hardness to 100 and paint the remaining background parts to pure white, you can see if it is all white or not by pressing the arrow at the top right part of the histogram, the red color will indicate the blown out areas.
You might think why didn't I use the umbrella to light both my subject and the background at the same time? I definitely could, I can push my subject's back to the wall and light them both with the umbrella, but I would lose an important degree of freedom, now I can't control how I light my subject, maybe I would want to use several lights on my subject (key, fill and rim lights). One other problem would arise if he was wearing a white shirt which would then be blown out no matter what you do.

BONUS TECHNIQUE: LOW KEY

Now that we've successfully created a high key image, here's a quick rundown of how I created the low key image at the top of the post. This image has won a "shadows" mini-challenge on dpreview.

Before taking the picture, me and my subject had a vision of how we wanted it to look like, we wanted one side of his face well lit and the other side completely in the shadows, and since we were outdoors during sunset this meant I had to kill the ambient light completely, luckily enough I had my Canon G11 which could sync up to 1/4000 sec. This is how the ambient looked like.

Ambient, 1/125sec, f/5, ISO 80 - Click to see a larger version

I used my bare (i.e. no modifier) speedlite triggered wirelessly and located very close to the right of my subject's face, this provided hard light and lots of shadows, exactly what we wanted, here's a test shot.

First test, 1/400sec, f/8, ISO 80 - Click to see a larger version

You can still see the ambient, the G11 can't go below f/8 and I was using the lowest ISO possible, the only remaining way was to increase the shutter speed, no problem since my G11 can sync at any speed.

Second test, 1/500sec, f/8, ISO 80 - Click to see a larger version

Better, but not there yet, unfortunately for some reason my wireless trigger had battery problems and didn't want to sync beyond 1/500 sec, so I was stuck with the ambient you see above, no problem. We got the wanted pose, we were looking for a scary look and to a large extent it was lit like the first test shot you see above.

Some post processing was required for the final result, first of all I increased the blacks slider to get the background to almost 100% black, then I used the adjustment brush with exposure set to -4 to change the rest of the background to complete black. I also used the adjustment brush to turn the left side of his face to complete black as well since I wasn't able to do it just with the speedlite, the final thing was to convert the picture to black and white by pulling the saturation slider all the way to the left. Below is the final result.

Final result - Click to see a larger version

You can see that the low key images are a little easier than high key images, and you can do them with continuous lights and long exposure times without the need of a flash, and you also have lots of possibilities with post processing.

I hope you have enjoyed this tutorial, please let me know if you have any comments or inquiries.