Using a flash for food photography has gotten a bad rap in food blogging circles. This is because people only try using the flash on their camera. If you use an off camera flash you can recreate any type of lighting. The techniques you need to learn in order to control the light from flashes are also useful for modifying naturally available light.

Strobist.com is a great website that popularized the use of hot shoe flashes off camera. It is run by David Hobby, a newspaper shooter turned instructor. While the site doesn’t focus on food photography, it has great lighting techniques and tutorials.

The current practical exercise is on food photography! The Strobist community has uploaded a ton of great examples of food photography onto the site’s Flickr group. Members document the lighting setup they used so it is a great way to get new ideas and see what works.

I had a hard time picking what to upload for this week’s exercise. I ended up going with the photo above of pickled spring onions. I ended up with a couple of other fun shots:

Here is the setup I used…It was a piece of plexi glass, with a flash bounce off below the subjects. There was another flash, fired through a softbox, camera left and behind the subject.

Perspective distortion can be a tricky subject to understand; luckily it is easier to see than explain. It is directly related to the distance between the subject and the camera. The distortion occurs from trying to take a 3-D world and mapped it into a 2-D plane in the camera.

If you take a photo of a plate of food using a wide lens like a 28mm lens and then take a similarly framed photo using a 200mm lens, the two photos will be slightly different. In order to have the the plate of food fill the same amount of the frame, you have to get much closer using a 28mm lens. This is because the 28mm lens does not “zoom in” as much, but instead captures a wider angle field of view than a 200mm lens. While the plate of food will fill the same portion of the frame, the wider angle will include more of the objects around the plate and include more of the table.

Being close to the plate also introduces some distortion. Objects that are closer appear to be much larger than objects which are only slightly farther away. The result is that the distance between objects on the table gets distorted. The plate that is the subject of the photo appears to be very prominent while a candle further down the table would appear to be smaller and more distant than it actually is. This effect can useful if you are trying to place a special emphasis on the plate of food.

The illustration above shows the different camera positions that are needed to capture a similar photo using a zoom lens and a wide angle lens. With the wider angle lens on the right, more of the area surrounding the place setting gets captured in the photo because the lens has a wider field of view. In order to have the place setting fill as much of the frame with the wider angle lens, the camera has to be much closer.

The following photos show the difference distance makes and the effect of perspective distortion. Each photo is composed the same with the cutting board filling the bottom of the frame. It starts with the lens set at 135mm and goes down to 28mm, with each photo getting closer to the cutting board. Notice how the lines of the table and the sides of the cutting board converge together more dramatically as the camera gets closer. The last photo shows a comparison of this. The important thing to remember is that there is no correct approach, it is just important to be aware of perspective distortion so you can better achieve the look you are going for.

The softness of a light determines what kind of shadow the light creates. Hard light creates shadows that have very distinct edges. The edge between where there is a shadow and where there is light is very sharp and distinct. With soft light there is a much gentler transition between shadow and light.

So what makes light soft or hard? It is all determined by how big an object is compare to the source of the light. It is not how big they are when they are next to each other, but instead as they are positioned for the photo. The distance between the source of the light and the subject has a big influence on the softness of the light. A large source of light will start to look smaller and smaller the farther away it gets positioned.

Take the sun as an example of a light source. The sun is huge! It is larger than anything on Earth, in fact it is larger than Earth. Luckily the sun is very far away, and actually ends up being pretty small relative to most subjects. On the next sunny day hold out your hand near the ground. It will cast a very sharp shadow.

The sun creates hard light because the light it gives off comes from a single direction. As the source of light gets larger compared to the subject, the light it gives off appears to come from many different directions.

A cloudy day is a good example of a soft light source. The sun’s light gets diffused by the layer of clouds. Instead of just a small spot in the sky giving off light, the whole sky is evenly illuminated. The shadows that are created are less distinct if they are there at all. Light is coming towards the subject from multiple directions.

If this is confusing, don’t worry. There are lots of other (better) explanations online. As always The Strobist does a great job of explaining it all.

All of this is great, but chances are if you are photographing food, you are not taking photos outside. You want to be able to create soft light when you want instead of having to wait for a cloudy day. Luckily it is not hard to do, unfortunately it will probably take a lifetime to master.

A small light source, like a desk lamp or flash, can be made to appear larger, and therefore softer, by bouncing the light off a large surface or diffusing it through a piece of material. It is probably easiest to experiment with bounce light. You can use the ceiling or the wall. If you want to get more creative, try using a piece of white cardboard or foam core. When the light bounces off the other surface, that entire surface becomes the new light source.

A light source can be diffused by placing a translucent material in front of it. This could be a piece of cloth or wax paper. Depending on how much the light has spread, the whole surface of the material should light up and become a light source.

Using diffusion and bouncing, you can turn a small light source into a large one. The resulting light source will not be as bright because both methods eat up a bit of the light, but you can work around this.

I use small battery powered flashes for taking food photos. Since the subject of most food-related photos is pretty small, these flashes have plenty of power. In subsequent posts I will show some of the light modifiers I use, like umbrellas and softboxes, and what effects they can have.

Here is an example of soft light and hard light. The first photo shows softer light coming from a single small softbox positioned behind green garlic. The second photo shows hard light, which comes from a bare flash in the same position. Look at the shadows, and how sharp or smooth the edges are.

I keep meaning to do a long post on food photography, but never seem to get around to it. I started one here, but never really finished it. Posts on food photography is one of New Years resolutions, so now I have no choice but to do it! I am going to change my plan of attack though and start with a bunch of shorter posts. I am going start with illustrating the basics and then focus on using flashes to do food photography. A lot of these topics are covered in general photography books, but things are a little different when you are focusing a plate of food two feet away verses than a mountain range.

The first topic I am going to cover is depth of field, which is the amount of stuff your camera can have in focus at once. A large depth of field means that objects at a wide range of distances are all in focus at the same time. A shallow depth of field means that the focus will be very selective. You maybe able to keep one thing in focus and everything in front or behind it will be blurry. I am not a photographer, so I am going to keep it simple and explain it the way I understand it.

The depth of field is controlled by the aperture of your lens. The lens has metal blades which snap together right before each photo is taken. The size of the opening these blades make is the aperture, which is measured in f-stops.

Here is where it gets tricky. A smaller opening corresponds to a larger depth of field and a larger the f-stop number. Most lens’ highest f-stop is 16 or 22, which is a really small opening. Lens will have a lower f-stop of anywhere between 2 and 4. When the aperture is set to these lower f-stops, the metal blades do not close at all, letting as much light through as possible. With the lens blades wide open, the area in focus is very small.

There is one more fun relationship that you might have guessed. As you make the size of your aperture smaller, you need more light to get the correct exposure. In order to increase the depth of field and get more of the picture in focus, you need to get more light. The are a couple of different ways to get more light:

• if you are using flashes, you can increase the power of the flash
• if you are using light from a window or lamp, you can keep the shutter open longer
• make your camera more light-sensitive by increasing the ISO speed

There is one last thing to remember when thinking about depth of field–the camera’s distance from the object you are trying to photograph also effects the depth of field. The closer you get to an object, the smaller the depth of field. When you get really close to a plate of food to capture some detail, it becomes harder to have the whole plate in focus. As you move closer to an object, you have to increase the f-stop to keep the same depth of field.

Here is a chart to help illustrate how depth of field is affected by all of these different aspects, with the arrows showing the direction of the relationship.

Right about now you are probably pretty confused. The thing to focus on (pun intended) is that you control how much of your photo is in focus by change the depth of field by changing the aperture or f-stop. There is a lot of math going into all of this, but luckily there is an online calculator which lets you see how all of these aspects are related.

Additionally, cameras have gotten very smart. Simply set your camera to Aperture Priority mode and it will do the rest. You can choose an f-stop and the camera will do the rest to ensure that you get the correct exposure. The f-stop depends on what look you are going for. If you are using an SLR camera the view finder will look the same no matter what you set the aperture to. This is because the camera opens the aperture up all the way for focusing and only shuts it down when a photo is taken. Most SLR’s have a depth of field preview button which stops down the lens to the aperture you are using and gives you a preview of what your depth of field will be.

The real question is why would you want to do this? Well, being selective in focusing can direct the viewer towards the important parts of the photo and blur away clutter. At the same time you want to have enough of the photo in focus so the viewer can figure out what is going on. This is where composition and artistry comes into play.

Below is the same photo taken with different f-stops. This should help you better visualize the effects you can create. If you want to include everything that is on a plate, use a higher f-stop. If you want to focus on a detail, go with a lower f-stop. In order to keep the exposure the same for each photo, I turned down the flash each time I stepped the f-stop down. I started at f 8.0 because that was the highest f-stop I could get with my flash turned up all the way. If I wasn’t so lazy I could have increase the ISO sensitivity of the camera. Photography is full of trade-offs!

The lighting setup I used is below. It is a single flash, shot through a soft box. There is a small piece of foam core opposite the flash to help fill in shadows.

We have gone through the thousands of photos Luke took this past year and selected some of our favorites. They have been uploaded into a fancy looking Flash gallery, thanks to the Lightroom Software. We usually end up with lots of good photos that never get posted, or get posted in too small a size to be appreciated. One of our 2009 goals is looking at how we can improve how photos are incorporated here at Cookography.com. Luke also just got a new camera, so expect to see some more photography posts coming soon!

View the Gallery

I feel bad that I have been posting so much about our trip to Vermont. I thought I would slip this post in to break things up a bit. Have no fear, only a couple more posts to go on Vermont. That is what I am telling myself.

This is a picture of a head of purplish cauliflower that I picked up at our farmers’ market. The shiny surface is made possible thanks to a huge piece of tile board that we hauled back from Home Depot last weekend. This sucker was 4′ x 8′. Luckily we used ZipCar and got a truck. It was still a beast to carry. Anyhow, there is a great tutorial on how to do this style of photography, seamless white background, here. That is where I got the idea to pick up a piece of “Budget White Tile Board” as they call it at Home Depot. It was actually a pain to find. In our store it was located in the Molding Aisle, Aisle 23. The tutorial focuses on photographing people, but it can be easily adapted. I am still working on getting this technique down. I will post again with a number of different shots and light positions. Stay tuned!

Here is the setup I used. Basic principal is: have the background brighter than the foreground to blow out the highlights and have it appear all white.

First off, this is sort of a boring, simple photo. I just wanted to show how the different lighting elements contribute to the photo. The overall setup is pretty simple–the food is on a piece of white matte board that is resting on a folding work bench. There is a light stand with Nikon SB-26 flash and a shoot through umbrella to the left of the camera. On the other side of the table from the camera is another light stand and Nikon SB-26 flash with PhotoFlex Small LiteDome soft box. I got the softbox, stand and flash connector together as a kit, which was a great purchase.

One Light From Rear

As you can see this is a pretty simple setup. The rear flash casts a shadow that falls forward. The shadow is pretty soft though. The edge of the shadow is not a distinct edge and fades out gradually.

One Flash With A Reflector

So the only thing different with this shot is that I setup the umbrella in the front and to the left of the camera. The flash attached to the umbrella is not firing, but the light from the rear light is bouncing off the umbrella. Since food is a small subject you can really do a lot with just one light and a lot of reflectors. The shadows underneath the fava pod have lightened up a bit. The shadows in the front of the pods have also lightened a bit.

Two Flashes

Ok, here we have both the flashes firing. The dark shadows are largely gone and the lighting has become pretty even across the bean. The flash in the soft box was set one stop lower than the flash in the umbrella.

So let me know, is this helpful? Is there something I can explain in a little more depth? I will try to do couple more posts like this future, so now is your chance to shape them.