When you start into Macro Photography you quickly find thatis very important. A lot of your shooting will be done at small apertures like F8-F11 and you'll need some additional lighting. This is when you turn to flash. The type of flash you use and how you balance you flash output with the other camera settings like , and will affect the look of your Macro shot. There are many types of flashes that can be used in Macro Photography and we will look at each of these briefly here.
What to buy?
So you are going to buy a flash to help with your Macro work - what are you going to buy? I recommend you don't buy a specialised Macro Flash at first. You are more likely to get better use out of a regular flash. You can use the normal flash in other areas of your photography ie Portraiture and also make good use of it for Macro work also. If you then get more serious about your Macro Photography you could then look into the more specialised flash heads such as the Twin Lite and the Ring Lite. Of these two I would be recommending the Twin Lite.
FEF - Flash Exposure Compensation is a means of altering the output of the flash. It is expressed in positive and negative values. FEC can be used to balance the flash with the natural to produce a more natural looking shot. Flash Compensation only affects the flash output and in the system can be set in either the Camera or the Flash. In the automated flash modes the camera will calculate the necessary flash power required and the FEC value is added or subtracted to the calculated value and this new value is then used as the final flash output power.
There is a good chance that your DSLR camera comes with a pop-up flash. This flash can be used in Macro Photography. You will want to look into your manual and check out how to change the FEC. A good place to start is about -2/3 FEC. Take a shot and see how this looks on the screen and on the histogram then adjust as necessary. If your subject is very close to the front of the the will shade the flash, you will see this in the resulting shot as a arc shaped shadow across the shot. People have used tissues, ping pong balls and many other things to affect the output of the pop-up flash. There is also the commercially available Gary Fong Puffer Diffuser.
This is the flash that I would recommend you get first. Why - because you be able to use this with so many other areas of your photography. Again you will need a little -ve FEC to tone down the flash output. There are a very wide range of diffusers available for flashes and a lot of these can be used in Macro Photography. The diffusers soften the output from the flash and prevent harsh shadows. Some examples are the Stofen Diffusers and the Lumquest Diffusers.
Many of the flash heads available have tilt and swivel features and these can be used to alter the direction and angle of the . It is not usually possible to use bounce flash in macro work as a lot of the time you will be outdoors. Tabletop work would be the exception to this.
580EX II, 430EX II, SB-400, SB-600, SB-800, SB-900, EF 530 DG ST, EF 530 DG Super
Off-Camera Flash Connection
This cord attaches to the Camera Hotshoe and the bottom of the Flash. With this you can hold the camera in your right hand and the flash head in your left hand to provide directional lighting. This can be a little hard on the arms after a short while, which leads us to the next item.
With a longer macro and extension tube setup up it is possible that the subject will be close enough to the from element of the that the flash will not it fully. In this situation you can get a shadow from the ruining your shot. This is when a flash bracket can be very useful. The flash bracket will normally mount onto the bottom of the camera and raise the flash up and closer to the front of the . The tilt and swivel features are a big help here also. This can make a dramatic difference to your shots are you now have total control over the angle and direction which the is coming from.
When using a flash bracket with the system you will need an off camera cord to connect the flash to the camera. Alternatively you could use two flashes in Master Slave and the inbuilt trigger system but this become slightly unreliable in full sun .
These are often associated with Macro Photography. They consist of a control unit that mounts to the camera hotshoe and the ring lite portion connected via a lead. Some ( 180L) require an adapter ring that screws to the front of the before the Ring Lite can be clipped on. The Ring Lite has two flash tubes and these are independent. ie you can change the output power of each of them individually. Usually the easiest way to do this is with the Ratio setting. Typically you could set a 4:1 ratio, providing a difference in the output power so some shadows are present.
Ring Lites can product a very flat lighting and setting a ratio can help to prevent this. The Ring Lite is very hard to add an additional diffuser to. There is some diffusion built in but this is often not sufficient. The from the Ring Lite will always hit the subject very square on and this causes very few shadows, something that can work either for or against you.
MR-14 EX, EM-140
This is an other dedicated Macro flash head. Again you have a control unit on top of the hotshoe and leads to connect to the two independent flash heads. The flash heads on the twin lite can be adjusted in many different ways making it more versatile than the Ring Lite. You can adjust the heads in almost any direction to provide the exact lighting that you require.
In addition there are Stofen diffusers available for the MT-24 Twin Lite or you can also build your own using a variety of materials. I use two Gary Fong Puffer Diffusers held onto the heads with small Velcro tabs. The Puffer Diffusers are designed to mount onto the pop-up flash to provide some diffusion.
Both the Twin Lite and the Ring Lite have Modelling Lights built into them. With the Twin Lite, a Custom Function in the flash can be set to trigger the Modelling with a quick double tap of the button. This Modelling is then used to assist manual focus.
The MT-24 can fit directly to the 60mm Macro, 100mm Macro, MPE-65mm Macro but does require and adapter to the 180mm L Macro.
It is worth while pointing out that using either a Ring Lite or Twin Lite precludes the use of a hood.
MT-24 EX, R1 and R1C1
It is possible to use multiple flashes in Macro Photography. Your success will depend on the location and subject as these systems can take a little time to setup and get adjusted correctly. In these setups you might have a Twin Lite on the camera and a separate flash head on a stand or even positioned on the ground. The second flash could be used to the background while the Twin Lite is lighting up the subject. Multi-Flash is easier for Table Top Macro work than outdoor Macro work usually because your outdoor subject is more likely to be mobile.
The Ring Lites and the Twin Lites along with the 580EX can act as Masters in a multi-flash setup. also produce a ST-E2 that acts as the flash controller but has no flash tube. With cameras this can be done from the camera itself without the need for a flash attached to the hotshoe. This provides wireless off camera flash. The 430EX can only act as a Slave.
It is easy to get blown out areas from the flash refecting off of a shiny insect body, in some conditions is it almost impossible to remove these. Many insects are very reflective and a Diffuser can be used to reduce or soften the output from the flash. A larger, diffuse source is less likely to produce harsh shaddows. The Stofen and Lumiquest Diffusers are commonly available and useful in other areas of photography.
Small Round collapsible Diffusers can also be used to change the natural hitting the subject. You can you a small white Diffuser to block out the bright midday sun, or reflect more onto your subject. In a pinch I've often used my hat to shade my subject, but you quickly run out of arms to hold everything.
Many people make their own diffusers and flash brackets, milk bottles tissues and Aluminium foil are commonly used in home made diffusers. This is one area where you could save a little money. A search on will show a wide variety of home made setups.
Mastering the use of flash in Macro Photography will make a huge difference to your shots. A side benefit is that much of what you learn can be applied to other areas of photography ie. Portraiture.
Flash Photography with Canon EOS Cameras