Macro Photography for under $10
To take super-close-up images opens a whole new aspect of photography, but macro lenses can cost a fortune. Luckily, there are a couple of much cheaper alternatives on offer, and in this blog/video I’m going to take you through three of them.
Here is the test
image using the standard kit lens 18-55mm this was set to the full 55mm
Macro Extension Tubes
The tube contains no optical
elements; its sole purpose is to move the lens farther from the image sensor.
The farther away the lens is, the closer the focus, the greater the
magnification, and also the greater the loss of light. Lenses focus closer than
infinity by moving all optical elements farther from the sensor; an extension
tube simply imposes this movement.
Extension tubes without
electrical contacts will not allow an electronic automatic camera to control
the lens, thus disabling autofocus and in some cases forcing a user to shoot
wide open unless the lens offers manual aperture control. More expensive
extension tubes contain electrical contacts allowing the user to use autofocus
and electronically control the aperture of the attached lens. Other items like
lens adapters may unintentionally have an effect similar to an extension tube.
Kit lens 18-55mm set
to the 55mm end using all the tubes
A close-up filter is a lens that attaches onto the end of a
camera lens via a screw thread. The purpose of the filter is to decrease the
minimum distance that a lens requires to focus. For example most telephoto
lenses need the subject to be at least a metre and a half away before they can
focus. By attaching a close-up filter to the lens you can reduce this to maybe
0.75 metres.
Close-up filters are measured in Dioptre, with +2 being weak
and +10 being strong. A dioptre is a measure of lens power.
Kit lens 18-55mm set
to the 55mm end using all the filters = +17
Filters can be
“stacked” together (one filter screwed onto the lens and another screwed into
the first filter). When stacking filters always make sure that the strongest
filter is closest to the lens.
Cost about $8. The ring consists
of a lens mount on one side (which should obviously fit your camera) and a male
filter thread on the other; this should match the filter thread of the lens you
intend to use.
As the name suggests, a reversing
ring allows you to attach a lens to your camera backwards. This allows you to
get extremely close to your subject. The wider the angle of the lens, the
greater the magnification: a 50mm lens will provide a rough 1:1 ratio, which is
the benchmark of a ‘true macro’ lens. A 20mm lens will yield a massive 4:1
ratio. So if you've got an otherwise ordinary 18-55mm kit lens, you're sitting
on a great macro lens; it just needs a little help from a reversing ring! Because the
ring attaches to the filter thread, you can even use them on lenses that have
broken mounts: not an uncommon problem with cheaper, plastic kit lens mounts.
Kit lens 18-55mm set
to the 55mm end using reverse ring adapter
It’s not all good news though.
Reversing rings come with a couple of small problems. Firstly, when you turn
the lens around you obviously lose the CPU connection between the lens and the
camera, so say goodbye to autofocus, metering (in most cases) and aperture control.
Secondly you expose the rear element of the lens to the outside world. Indoors
this isn'ta huge issue, but it’s worth being aware of when you're outside on a
windy day or in other adverse conditions.
So, if you don't mind risking a
little dirt on your lens, or doing things manually, you can get into macro
photography cheaply and easily. Let’s look into it in more detail. The
advantage of this old lens is that it has a manual aperture ring, which neatly
neutralises the loss of automatic control mentioned above.
Most cameras will probably start
complaining that there’s no lens attached. Don't worry, just flip to Manual
mode. Now find a subject and frame it up in the viewfinder. What’s that? You
just get a blur? That’s because you have to get really, really close: at 18mm
you need to get within about 5cm/2” of the subject. So get stuck in.
The next thing you'll notice is
that the depth of field is wafer-thin. That’s an issue with all macro
photography – it’s a blessing and a curse, as it gives a nice blurred
background that emphasises your subject, but it can also mean that not enough
of your subject is in focus. Couple that with the fact that you're focusing
purely by moving back and forth (or breathing!) and you have a tricky situation.
But the great advantage of digital photography is that you can take as many
shots as you need to get things right, so, onwards and upwards.
Here are all the test images side
by side
Image1 Kit lens set to 55mm.
Image 2 Extension Tubes.
Image3 Kit lens set to 55mm with
all Filters +17.
Image4 Reverse Ring Adapter.
No comments:
Post a Comment