Tips for making your super macro super...
And a little easier
By Kevin Palmer
So what is the difference between macro - already pretty small - and "Super Macro"?
- As a rule, conventional macro maxes out at 1/1 which means the size of your sensor will be the same size as a subject that fills the frame of the shot. On a 35mm sensor, 1/1 means you can fill the frame with a subject about 30-35mm long.
- Super Macro is often defined as anything beyond that one to one level of reproduction on your camera’s sensor
- The tools required? A Macro lens or long standard focal length lens on a compact. Close focus wet lenses or teleconverters. A method for locking focus, and of course, abundant patience.
Tools:
Macro Wet Lenses are one of the most popular ways to increase magnification and they offer the flexibility to be removed during the dive, but they also Reduce Minimum Focus. This means getting closer than you think. If a quality optic is chosen and matched to the lens, this option offers the highest potential image quality.
A tele-extender (also called a tele-converter) can increase magnification from 40-100% without reducing minimum focus – which is cool, but you give up some image quality in the process and you can't take it off underwater.
Could you go crazy and use both tools at once? Absolutely - but realistically, there are so many lens combinations and high quality water contact optic options, that probably won't be necessary for amazing super macro. Lets look at the options more closely.
Since macro wet lenses have become so popular and produced by so many manufacturers, it pays to understand all the nomenclature around them.
+5 +10 +15 +25 - what does it mean?
This known as a diopter rating. Just like the diopter rating of your reading glasses if you use them. Many macro wet lenses are rated this way from +5 to +25. There is a formula to calculate your exact minimum focus distance depending on your lens when using wet lenses rated in diopter strength, but knowing that really doesn't make our photos better. Suffice it to say that the higher the diopter rating, the closer you will have to get to your subject to achieve sharp focus. It also means, the closer you get, the more magnified your subject will be.
These standard diopter rated lenses have been made for underwater imaging for years and there has been a range of quality. People sometimes ask if they can use there inexpensive terrestrial close up lenses in the water, but because the lens is curved for use in air, the minute you put it underwater, most of the magnification goes away - again, not useful.
The way manufacturers got around this problem was by taking inexpensive diopter rated lenses meant for use in air, then sandwiching them between two pieces of flat glass that are sealed - and voila', in-air performance. The downside to this set up is that every time water hits flat glass, there is some diffraction that causes chromatic aberrations ("CA" for short), which means colors don't quite line up right. So on a flat port for your lens, you get a little bit, but add a diopter rated close up lens and it is at least tripled. And you have to get really close to your subject. So it works, but there are newer, better solutions.
The introduction of this lens about five years ago changed everything with super macro. Nauticam re-thought the problem and after hundreds of hours of computer algorithm time, came up with a design that had no flat glass and all the elements were designed to function in water as a combination of traditional close up lens and tele-converter. So more magnification, less CA and less reduction in minimum focus distance. When we first tried the lens on a dive next to a traditional +10 rated close up lens, the difference was astounding. Not only did the SMC provide more magnification and working room, it was easier to see through and easier to focus through. The image quality was also vastly improved. The lens immediately became the standard of the industry. Since that time, Nauticam has introduced the SMC-2, the CMC-1 and the CMC-2. These are all macro wet lenses uniquely designed for different applications, but with the same philosophy of purpose. You will notice that none of these lenses are diopter rated, because they are not made with diopter rated off-the-shelf glass, they use different custom lens technology. These lenses are generally a bit more expensive than standard diopter rated wet lenses, so each shooter needs to asses what will best suit their needs and we are happy to help if it all seems confusing! Remember, the more magnification, the more challenging the shot will be!
Focus, Focus, Focus
The difference between a knock-your-socks-off shot and an "oh that's pleasant" shot is often just a few millimetres of focus variation. With today's high resolution cameras and super macro's shallow depth of field, you need all the help you can get to dial in the shot.
- Tool number one: Unless you have the perfect vision of a teenager, you will probably want an Enhanced Viewfinder. These viewfinders will enlarge the image and allow you to see corner to corner at all times. If your camera has an Optical Viewfinder (as on a DSLR camera), there is likely an enhanced viewfinder for your housing. If you have an Electronic Viewfinder on your mirrorless camera, there is still often an enhanced viewfinder option. If you are shooting a compact camera with only a LCD viewer, many housings now have the option for an LCD Magnifier attached to the back that makes viewing easier.
- Tool number two: If you have a camera with an interchangeable lens that allows for a manual focus gear control - super macro is a good reason to jump in and go for it. Manual focus while you keep your eye on your subject can make life easier.
- Tool number three: Don't have that option or just don't like the idea? Learn how to lock your focus when you want to. For most DSLR and mirrorless shooters, this will mean setting "Thumb Focus or Back Button Focus" on your camera. That is usually, but not always, achieved by removing the AF activation from half depress of the shutter button and and assigning it instead to the AF-ON button (it might also be AE-Lock or something else depending on the camera). If this makes no sense to you, contact us and we will be happy to help. Some people prefer AF-Lock - it is the same control, but now you will HOLD the button when you want the camera to stop focusing on its own. Lastly, with some cameras there is an AF/MF switch, this might be a programmable button or a physical switch labeled AF/MF. So any time you want the camera to stop focusing on its own, just flip the switch or hit the button.
- Tool number four: The camera and the photographer can't focus on what they can't see. So a good housing mounted Focus Light is essential! There are lots of reasonably priced lights these days, but it is worth buying something that you will find comfortable to use night and day and has at least a good wide even beam (so you don't have to adjust it during a dive) and a red mode for skittish subjects.
So why all the fuss with stopping the auto-focus? Take a look at the shot below, this critter is commonly called a Ladybug and it is only 2-3mm long. What are the odds your AF is going to lock on to its little eyeballs by itself?
By locking focus or using manual focus we can make slight adjustments in composition and movement forward and backward without the camera hunting for new focus. Equally important, we can take several shots in a row without having to catch focus each time. This can make a big difference in our success rate! Of course, this also requires being able to see your subject clearly - so good viewfinder function is also important.
Composition and Plane of Focus
Isn't it hard enough to just get the shot rather than have to also worry about composition? Well it is true that it is challenging, but any of us who have attempted shots of things like hairy shrimp, or skeleton shrimp, know that 9 out of 10 shots of these things are unrecognizable. Photograph the back end of a hairy shrimp and you pretty much have a fuzz ball - not pretty. Have you ever noticed the pygmy sea horses hate looking at the camera? Yes, we have all been there.
So, as a rule, when possible, try to find a background or open water that allows the outline of the subject to show clearly. Not always possible, but try. Next, we have to get an eye, our what passes as an eye on some animals (rhinophores?) - this will usually be the primary point of focus if it is a critter. Abstracts (often a great place to start and practice) can be a lot more forgiving!
Look - no eyes to keep in focus
Even, with this kind of shot, pick the right eyes to focus on!
Eyes and background!
OK, can you see why this shot isn't as good as it could be? This is a 4mm nudie - so it is challenging and very shallow depth of field. There is no eye, so the rhinophore should be the target. But I got the back one instead of the front one - that is why we lock focus and take several shots!
Aperture Settings
Because Super Macro by definition is shallow depth of field (all things being equal, the greater the subject magnification, the less depth of field), there is a tendancy to shoot images with the smallest aperture possible. On a DSLR camera, this can be as small as f64! In the old days of digital and older days of film, there was a definite limit to the detail that could be captured and we didn't notice a problem with stopping down our aperture. With modern digital cameras, the resolution is so fine, we now notice the impact of diffraction. Diffraction is what happens when the opening of the aperture is so small that the light rays have to spread at a very steep angle to hit the sensor. This makes the image look softer and you loose detail.
In this series of crops done by Alex Mustard, you can clearly see the effects of diffraction.
This doesn't mean you can't stop down your aperture for Super Macro, just try to use this tool in moderation and realize there is no "free lunch" when you do so. A good compromise for full frame cameras might be to use nothing smaller than f22, but each situation is unique and over time, good judgement will produce good images.
The more tools you have and the more practice you engage in, the more impressive your results will be. Super Macro can be found on every reef in the ocean - and it opens a whole new world.
We cover many of these techniques in our workshops - check them out and let us know if you have questions!