When you think about macro images, we often imagine those really, really detailed close up photos. As long as there is good lighting, it’s simple to do with focus stacking or even just stopping the lens down with enough light in the scene. Many photographers on their spare time adore the meditative act of fixating on an object and photographing it to get every single detail of the subject. These objects are typically small toys, food, insects, plants, etc. It’s fun and requires the photographer to make a number of very repetitive but careful movements. But of course, every bit of lighting is always useful and we don’t always have good lighting naturally around. But don’t worry: using a flash in this situation is pretty much brainless.
Aperture and Lighting: How They Work
When you stop your lens down, what happens? Obviously the depth of field becomes wider, but what about the light? If your shutter speed and your ISO stay the same, then the overall image becomes darker. That’s how flash exposure works–except it’s directly tied to both ISO and aperture. So the way that flash works in this case is by looking at your ISO number and then adjusting accordingly. The more you stop your lens down, the more power your flash will need if your ISO stays the same. This is how TTL flash works. But if you’re shooting manually, then it’s a different story.
” Eventually I realized that I needed to take the flash out of the hot shoe to get the looks in the images that I wanted. So I saved up more money and bought a used Canon 580 EX II off Craigslist. A little while before this, I had purchased a Canon 7D to work with my 5D Mk II as a second camera and a backup body. So now, I had two camera bodies and two flashes–the staple that every pro should really have if you’re actually earning money from your photography.” – What I Learned from One Year of Shooting Manual Flash
Here’s another way to think about it all–try this:
- Put your hands on the sides of your eyes. Notice how little extra light comes into the scene
- Bring your palms in closer and realize how little extra light is getting in and reaching your eyes
- Bring them in even closer.
That’s sort of how this works though not totally. However, the concept is the exact same.
Make it Look Natural: Making a Flash Look Like Natural Light
The key to making the output from a flash look like natural light is very simple. Are you ready for the incredibly simple secret?
Just create a light source or modifier that is larger than the subject matter!
In the case of macro photos, your subjects are often very small, and so a modifier that is larger than the subject (pretty much anything) will work. One of my favorites is a Rogue Flashbender. That’s how the above photo was shot with the flash in TTL mode. Just make sure that the light source is pointing directly right down onto the subject and that it’s angled to hit the top of your lens. Then you just need to shoot and figure out angles.
If you’re using manual flash then it’s a different story–sort of. You need to control the flash output. Sometimes you want a darker photo and sometimes you don’t. You have more control in manual but arguably that same control is available in TTL and in some ways easier. If you’ve worked with manual lighting before though and know exactly what the answer to your equation is then you’ll notice that it’s simple.
A Tripod: You’ll Need It!
Despite the fact that image stabilization exists; if you’re going to use a longer focal length to get a macro image, you’ll really need a tripod. Holding a focal length by hand and focusing at a macro range intensifies any sort of camera and hand shake that you’ll have. Even with a fast flash duration on your flash, it may be very difficult to get a blur free image. When you go to shoot, be sure to turn off the image stabilization on your camera and your lens. And for even better results, shoot at a delayed shutter speed.
More to the idea of using a tripod, it’s a fantastic compositional tool besides just providing image stabilization that otherwise isn’t possible. Landscape photographers have known this for years and photographers who shoot macro images for a living often have very advanced and complicated setups.
And the last tip: a flash has something called a flash duration that stops a lot of movement, ideally. But it also adds something called specular highlights, and those make your images sharper.