Macro is a very popular aspect of underwater photography and early success at it can be very satisfying.
I'm a big fan of macro photography as some of you'll be well aware. For folk keen on marine life it concentrates your mind on what can be found on almost any dive. I never do a dive and come up saying I've not seen anything, there's always some tiny new critter to come across.
Once you get in the macro mindset it can quickly give you satisfying results, but you do need to have a grasp of some of the basics.
So let's get started.
What is Macro Photography
Macro photography can be considered the taking of images where the subject appears at life size or larger on the camera's sensor. You will hear the phrase 'super macro' and this really just refers to very magnified subjects.
Close-up photography is used sometimes to describe taking pictures where the subject is 1/10 size down to actual size on the sensor but is often used as a catch all included macro in with it as well.
Many compact cameras have macro modes, what these do is allow the camera to focus closer than normal. This is an advantage when using the camera on it's own to take macro shots. But these modes tend to work best with the camera's lens zoomed to it's widest.
Macro Wet Lenses or Diopters
These are add on lenses that fit on your housing port and in simple terms increase the magnification of your camera's lens (it isn't quite that simple but for most purposes this will suffice). Diopter is just another photographer's term for this type of lens, originally coming from the measure of lens strength. This is the number that most manufacturers rate them by. A higher number means a more powerful lens. Common powers tend to be +6, +10 and +12 but there are lenses out there that equate to +15. It isn't clear cut to say how magnified your subject will be because this varies not only by what wet lens you add but also by the focal length of your camera's lens.
When using macro wet lenses you need to be aware that they reduce how far your camera will focus to and also the depth of field you have available. The more powerful the wet lens the closer you need to be to get the subject in focus and the less depth of field you have. So you have to get close to your subject and it will be harder to get the part of the shot you want in focus. You can balance some of the loss of depth of field by using a smaller aperture (higher f number), but remember this reduces the amount of light being allowed in to the sensor and at very high f numbers such as those available on DSLR's image quality can begin to suffer and images appear less crisp. As always camera settings are a juggling act and there is no perfect magical setting for every situation.
If using a camera with a macro mode you should turn it off. When using a camera with a zoom lens you will usually get best results with the lens zoomed in.
You can stack some wet macro lenses together to produce a more powerful effect but focusing will get closer and closer to the front lens until if you go too far with your stacking the camera will stop focusing beyond the front of the outer lens.
So how do I get good results using macro wet lenses?
Don't be too ambitious.
We suggest going with a lower power wet lens to start with. Maybe a +6 and then once you are getting satisfactory results move up to a +10 or +12 or stacking a couple of +6's.
Master buoyancy control before you start.
For me macro is all about getting positioned to reach small creatures without disturbing them and once I've got in that position holding steady while I take the shots.
Don't just snap.
Take your time with your subject. This goes for all underwater photography. If you want your pictures to be good you need to commit a significant amount of time to each set of pictures.
Then take multiple shots.
You'll seldom get your first shot right. With a small subject and a powerful macro lens giving you a shallow depth of field, you'll sometimes take a lot of pictures to get that one shot with the eyes in focus. And sometimes you won't get any right. Focus the camera on the point you want in focus but then take strings of shots holding the focus because slight movements of the camera and/or the subject will take place. I find Single Auto Focus works well for this, using a half press of the shutter button to set the focus. I then just make fractional movements of the camera to try to get the subject correctly focused.It's very much trial and error.
Choose your battles.
If you don't have a strobe you'll need bright conditions because by the nature of adding the macro lenses you are reducing light getting to the camera sensor. And when you have to get very close to what you are taking a picture of you'll find you tend to block the light with the camera and your body. This is why for divers keen on macro photography we tend to recommend a strobe set up as an early purchase. You may get some results using a built-in flash but often you'll find the macro lenses cast a shadow.
Learn to use manual settings.
As always you'll find you get better results once you take control of your camera and learn what changing aperture, shutter speed and ISO will do to your pictures. The camera rarely gets it right of its own accord when underwater. the more help you give it the better.
So that's the end of part one of my musings. 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 courses (dates are on our Events page). Anyone is welcome to join the Alphamarine Photography Q and A Facebook group as long as you behave yourself and stick to the rules.