Macro

Now, there are several lenses out there with the inscription ‘Macro’ on it, but a true Macro lens has a reproduction ratio 1:1 or greater. The reproduction ratio, is the subject size on the sensor, compared to the actual subject size. In other words, with a reproduction ratio 1:1, a 5mm subject will project as a 5mm image on the sensor. If you reduse the reproduction ratio to 1:2, the 5mm subject projects as a 2.5mm image on the sensor.

So, a lens like the Sigma 17-70mm f/2.8-4 DC HSM OS macro can focus down to 0.22m which gives you a max object magnification of 1:2.7 at 70mm. Pretty good, but again, not a true Macro lens.

When we talk about minimum focus range, this is usually referred to the sensor. For the Sigma 70mm f/2.8 EX DG macro the minimum focus distance is 0.257m (25.7cm). This is from the camera sensor, hence the real minimum working distance is actually approx. 6.5cm. The human eye typically has a minimum focus range of 13cm.

Tips & Tricks for photographing insects

Insects will be afraid of you, and fly away. But if you are hanging around, they may adapt, and start to come back. Patience is the key.

Keep in mind that most insects are cold blooded, and they need sunlight to warm up. Before sunrise or after a heavy shower, would be a good time to catch them sitting still.

Some insects, e.g. bees and bumblebees, love a sweet treat. You could mix sugar and water, and use as bait.

Use a tripod and a remote shutter to avoid motion blur from camera motion, and a fast shutter speed to reduce that of moving subjects. A Macro Flash will help preventing any motion blur.

Typical aperture values for photographing insects: f/11 – f/16.

Remember that the Depth of Field (DOF), i.e. the range within a scene that will record as sharp (how much of your photograph is in focus from front to back), is very limited when shooting a macro. The reason for that, is the short distance to the subject, which is one of the factors that effects the DOF – short distance, short DOF.

Focal length: 60mm, Aperture: f/6,3

At a distance of 30cm, using a 100mm lens on a camera with a crop factor 1.5 you will get a DOF as follows:

f/2.8 > 0.07cm
f/4.0 > 0.10cm
f/5.6 > 0.14cm
f/8.0 > 0.19cm
f/11  > 0.27cm
f/16  > 0.38cm
f/22  > 0.54cm
f/32  > 0.77cm