{Pete Larson} Photography

Using Off Camera Flash Tutorial

This is the first of what hopefully will be a series of tutorials on photography techniques. I frequently get questions and email as to how I created a specific shot. What camera equipment, lighting setups, lens, aperture and shutter speed choices and on and on. So I've been wanting to find the time now for a while to try to put some of the most frequently asked questions into tutorials to try and help other photographers. After all, it's all about helping each other, right?

OK, for it this first tutorial we are going to jump right into the technique that will be a little in advanced or some photographers. However, it really isn't that hard once you understand the concepts. I will do my best here to try to break it all down in a logical manner and make it easy to understand. Now I want to state right away, by way of doing things is definitely not the only way. What I intend to show here is the methods I use an have been successful for me. There are certainly lots of other articles out there on the subject of off camera flash. When I first began exploring and learning to use this technique I struggled, like probably a lot of you might be doing now. The information I was able to find, oftentimes just left me more confused. My main goal here is to try to avoid the confusion.

This tutorial is only going to deal with the use of off camera flash and is not intended to teach you the basics of photography. As mentioned this is an advanced topic. If you do not already have a good understanding of the aperture, shutter speed, ISO and how they all interrelate, then I suggest starting out with tutorials which cover those basics first. We will be shooting in full manual here and understanding is imperative for success.

Here is the photo we are going to examine today. It is a photo of Cassandra a beautiful and energetic young model I had the pleasure of photographing recently.



OK before we get into the technique I will explain the equipment and set up I used to create this image. I am a Canon shooter so my equipment is based on that system. My usual setup for creating these types of images consists of the following equipment that I bring to with me to a location shoot. I like to make as simple and as easy as possible. Traveling light to a location shoot is always better than being weighted down with a tons of equipment, I probably won't use. Notice I said LOCATION shoot? My setup differs greatly when I am shooting a wedding. I always bring back ups of everything to a wedding. For this shoot, I used the Canon 5D Mk II body, and the 70-200 f.28 IS USM lens. For the lighting I was using two 580 EX II's, each in a Lastolite Ezy soft box. The soft boxes are mounted to mono pods for mobility and were triggered by Pocket Wizard, T5's and a T1 Mini mounted on the camera. I use the Sekonic L-358 light meter, which is just excellent. That's it! That's my total system for location shoots.

First things first.

The first thing I'd do is select my background. I want a simple background, yet one that will give a pleasing result to the image. Then I place my subject, in this case, Cassandra into the scene. I had her stand in the middle of the sidewalk, knowing I was going to throw most of the background out of focus. Notice how the out of focus trees frame her upper body and head?

The next thing I look for is the ambient light. Where is it coming from? Is it even or is a directional? In this case we had tall buildings on my camera right and they were blocking the sun from casting the sunlight directly on the model. The light was flat for the most part. That's exactly what I wanted. I want to control the light and create the image I want to see.

The next thing I do is position my two assistants who were holding the flashes for me. I positioned one light at about a 45 degree angle to the camera, slightly above the model, at about an 8' distance from the model made that the key light. The beauty of off camera flashes that it is directional and flattering to the model. The soft box softens and diffuses the light. The result is a light quality we want to achieve here.

The second light was placed behind and to the right of the camera at about 10 feet from the model. I knew this light would add a rim light to the hair of the model and highlight her left side. You can see evidence of what that light contributes to the image if you look for the highlights on Cassandra's left side. But, unless you know what it is, it would pass for sunlight. That's the basic positioning of the lights.

Manual flash & camera settings.

Both flashes were set to manual mode at 1/2 power, which I find is a good starting point. The key light here is stronger and contributes more to the image exposure. how come? Because it is closer to the model than the fill light and more of the light from the key light falls on the model. It is important to make sure your choice of flashes will allow you to place them into manual mode. Why? Because we want consistency. When the flashes are set in manual mode, they will fire at exactly the same output, time after time.

The new Pocket Wizards are capable of firing the flashes in their default mode of E-TTL, but I find that mode kinda iffy at best when using the flashes in soft boxes. The reasons for that is the way E-TTL (Through-the-Lens) metering works. And that my friends is a whole other topic for another tutorial. There are times I do use the E-TTL capabilities of the new Pocket Wizards and it generally works wonderfully, but not here. So the flashes are set to fire in manual mode.

The camera is also set to manual mode. Again for the same reasons, consistency. Once everything is set, you can shoot and shoot and get exposures you expect time and again. White balance was set to auto and I was shooting in RAW mode for reasons I will explain later on in this tutorial.


Take a look at the diagram below wich will illustrate the set up in a graphical manner.


Lighting positions and exposure settings.

I positioned the "key" light to be about 8 feet from the subject and had the assistant hold it slightly above Cassandra's head. The fill light was set back a little farther at about 10 feet. I had pre-determined I wanted to use an ISO of 100 and a shutter speed of 1/200 of a second which is the max flash sync speed for the 5D. The reason for this is twofold. First it would allow me to get a wide aperture and the flashes will recycle at a faster rate this way. The reasons why this happens is again another subject for another time, but just trust me it does happen this way.

Another way to choose your shutter speed is to take some test shots without using the flash, moving up or down on the shutter speed until the ambient light, i.e. the background looks how you like it. You should know that Shutter speed has no effect on flash exposure. Since flash is fast and shutter speed can be fast or slow, depending on you adjust your settings. Another way to think of it is like this. We are going to use the Shutter speed to control our ambient exposure (background light) and the aperture to control our flash exposure and light falling on our subject. Moving on.

I then took a meter Reading with the light meter while I fired both flashes. The result was a reading of f4 @ 1/200 at ISO 100. Perfect! The shutter speed of 1/200th and ISO of 100 that I had already predetermined gave me a reasonably wide aperture. With those two settings already known, the only unknown setting was the aperture. Experience told me I knew I would end up with something in the range of 5.6-3.5ish. Now I set the camera to match those settings, and we are ready to go. This is why manual mode is important. The goal we are going for here is to BALANCE the flash with the ambient light so the flash is almost imperceptible within the image.

more on depth of field

The next thing I wanted to do was control the depth of field and compression. This is not so much about off camera flash, but it still is a factor worth considering in the context of the image as a whole. I already knew I was going to have an aperture of f4 and that was going to give me a somewhat shallow depth of field, and throw the background out of focus.

I wanted to increase that out of focus look just a bit more, while preserving focus of the model. Since the flashes are already preset at 8 feet, 45 degrees and slightly above for the key light and 10 feet, behind and slightly to the model's left side at roughly the same level as her head, I did not need to worry about my camera position relative to the model. I knew my exposures would remain constant and predictable. So I gave myself a greater distance from my subject. In this case, (according to my Exif data) I was positioned at 37 feet (11.3 meters) from the model and I was zoomed all the way in to 185mm. Doing this allowed me to compress the background and pop the model off the background. Very nice!

One consideration here to keep in mind. With modeling photography, you do not necessarily want too much of your subject to be out of focus. This is especially true if you are doing a clothing shoot. Designers are not going to be too thrilled if the shots you deliver have sharp focus on the model's face but fall off on the clothing details. So where I might choose something like f2.8 or wider if I were doing a general portrait, in this case, something in the range of f4 to 5.6 is good.

Gaining Confidence

The exact positions of the lights are a creative decision with lots of latatude and freedom. The best way for me to approach the arrangement with the lights is to set them up in approximately the setup I was using above and then take a shot, chimp and see what you get. Zoom in to see how the light and shadows are falling on your subject. If you find you are not getting good modeling on the face, tweak the lighting and try another shot. Keep doing this until you achieve the look you are going for. Conversely you can adjust the model's position too. Just don't move either the lights or the model too far or you will change the exposure. That is easy enough to deal with though, just take another meter reading and readjust your settings on the camera as needed.

Using off camera flash can be intimidating at first and you will most likely get some really strange exposures starting out. But soon as you gain experience, through practice, you will be able to quickly dial in your settings and move from shot to shot with great ease. When you either change locations or if the model drastically changes her pose or position relative to the original setup, just repeat the above steps and you are back to shooting. The good thing about shooting this way, just as shooting in a studio, as long as your set up does not change, you can shoot and shoot and get consistent exposures. Another benefit to shooting in this style is the creativity it brings to your photos. You are truly creating the image, hardly a snapshot. You will be making images for your clients that they or their friends or family probably won't be able to create for them. Your clients are going to love you for it too!

Raw an important part of the technique.

As I mentioned earlier I was shooting in auto white balance and RAW. I know there are some photographers who will banish me for using auto WB, but since I shoot in RAW I am able to adjust the white balance exactly how I want it in post production and processing of the images. Yes that does increase time spent processing images, but remember you are also using flash. In some cases unless you are going to take the time to gel your flashes you are going to need that extra flexibility RAW provides anyway to match the two light sources (ambient and flash). And it RAW makes it so easy.

Final thoughts.

Give this technique a try sometime and I think you will see you can really create some stunning images when you apply these methods and practice, practice, practice.

If you enjoyed this tutorial let me know it was worth reading and I will continue to create more. I invite you to use the comment box below to ask any questions you might have and I promise to answer them as quickly as I am able. If you have ideas for other topics you would like to see for future tutorials, bring em. Now go get some great images!

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