In part one of my macro musings I talked about what macro is and a bit about macro lenses. Lets move on to a common question from would be underwater photographers.
How do you get a black background in your macro shots?
This is a really popular look to give your images in macro photography and it's not that hard to achieve if you are willing to move away from the more automated camera modes and give Manual a try.
Getting a dark background is all about fast shutter speed and using flash.
Ideally you want a separate strobe to provide lighting, one is enough. But you may be surprised at what you can achieve with the built-in flash if your housing allows you to use it. Sometimes the lens port will just be too big for the built-in flash to be useful. But if you can use it then shooting with the camera vertical, portrait style, with the flash at the top will tend to give you more even light on the subject.
Crank up that shutter speed
To make the background of your shots dark you need two things to happen.
Firstly, you want as little natural light to get to the camera sensor. A simple option is to shoot in the dead of night, but a lot of the best subjects may not be out at night. Instead reduce the amount of ambient light in the shot by using a fast shutter speed.
Increasing shutter speed when using flash is not a problem for compact camera users. You can literally take it to as fast as it will go which for some cameras can be over 1/2000 sec. This means if you set ISO to 100 or 200 you'll generally be able to work with even a big aperture (small f number) without letting ambient light into the background of your shot.
If you have a camera without a full manual mode such as an Olympus TG5 try using exposure compensation at its lowest setting (-2 or -3 depending on the camera) to reduce the amount of background light in shots.
That Syncing Feeling
For the folk who've splashed out and bought DSLR's or mirrorless cameras they are limited to the flash sync speed of their camera. This is the fastest shutter speed at which a shot can be taken without dark areas caused by the mechanical shutter curtains appearing in the image. Modern cameras don't allow you to exceed this shutter speed when using flash. This prevents you from accidentally exceeded the sync speed and ruining your shots.
These days most new mirrorless or DSLr's have sync speeds of 1/250 or even 1/320. These give you a good ability to cut out background light. But you may find that you have to use smaller apertures (large f numbers) to help things along when background light is bright. As in most cases you want ISO to be 100 or 200 many cameras will tell you a recommended setting, my Olympus EM10 MkII does.
Now to the trickier second bit. Those new to underwater photography often ask about what camera setting to use but in reality it's much more about the strobes. Not just the settings but the positioning.
You want to position yourself so that ideally you have empty water behind the subject. This makes life a lot easier as the light from the strobe will only be on the subject with none of the background being lit by it.
But in many cases you will have something behind the subject. For example in the header picture for this blog, the squat lobster was in a small hole in a rock face.
To light the subject but not the background you need to take time positioning your strobe, moving closer to or further away from your subject and adjusting the power (this is partly why we recommend strobes with manual controls). You want to paint your subject with enough light while not lighting what's behind it. Having an arm system that gives a good range of movement and lets you place the strobe easily to achieve the results you want is another important consideration. Many of the lower end arm systems don't give you the ability to put your strobe at all points around your camera.
You can manipulate your strobe lighting further by using a snoot and we'll talk about that in another blog.
A bit of editing doesn't hurt
If you do get that lovely shot of something but the background isn't as dark as you hoped or there is something white in one corner of you lovely black background, don't despair.
No one went to hell for using Lightroom or Photoshop to do a bit of finessing.
Although if you are of a competitive bent make sure you check rules about editing before putting images in a contest. Some are stricter than others.
I'll be back with some more macro musings soon. If you want more specific advice or have a suggestion for a blog subject feel free to get in touch, details on how to do this are on our contact page. Do the same if you'd like a quote for equipment or to book on one of our photo courses or editing workshops (dates are on our Events page). Feel free to join the Alphamarine Photography Q and A Facebook group as long as you behave yourself and stick to the rules.