If parts of the subject are still out of focus, I use a technique called 'focus stacking'ĮDIT: The longer the macro lenses focal length, the shallower the depth of field at any given lens aperture. Then using the depth of field preview, determine the proper lens aperture. Once my lens is set to the exact image to subject ratio I need, I then use the rail mount to move the focus along the subject. I use a special 4-way rail camera mount attached to my tripod. If you try and "auto-focus", the image to subject ratio will change The other factor you need to know is that when you set a macro lens to a specific image to subject ratio like 1:2 or 1:1, the focusing becomes a function of you moving the whole camera an lens combination toward or a way from the subject. All APS-C sensors have a 1.5x crop factor but for Canon. What do the specifications say on the Sigma website. Just the mirror slapping during the photo can blur the photo from vibration. You will want to use a remote shutter, and if your camera supports it, use MUP mode (Mirror Up). If you are just getting into macro and don't care about bugs, then I would recommend something like a Nikon 40mm f/2.8 micro (which I own), But if bugs is your goal, then the Tokina 100mm f/2.8, Sigma 105mm f/2.8, Nikon 105mm f/2.8, and so on is your best choice… Along with needing a tripod and macro flash (at least eventually).Īlso certain techniques are in order. But if you are doing bugs - at least those not on display with a pin through them - you can't usually use focus stacking as bugs do not stay put for several photos. You can also use focus stacking as indicated above if you use a tripod and are not photographing moving objects such as bugs. Since the DoF is wider at the shorter focal lengths, lenses such as the 40mm macro not only do not usually need a flash, they can often be hand-held.īut with a 105mm lens, you all but need a tripod and flash to obtain sufficient DoF.Ī cropped camera will allow you to back up more for the same 1:1 photo, which means that the DoF will be a bit more favorable with a cropped camera, so you might get away without having to use a macro flash. This presents a problem… You will need a macro flash when going with that small of an aperture - even in the direct noon day sunlight. And in fact, lenses such as the Tokina 100mm macro (which I have), you can go all the way down to f/64 in macro mode. DoF at macro ranges is wafer-thin, and with a 105mm lens, you typically have to use apertures of f/11 or smaller to obtain a suitable depth of field (in-focus area). So… This means the 105mm lens is better for bugs as you don't have to get as close to obtain the photo (or perhaps scare off the bug), and indeed, the 105mm lens is preferred for bugs over the shorter focal lengths precisely due to the longer distance.īut that also carries a penalty… DoF. So the Sigma 105m lens having a close focus distance of 12.3" to produce a 1:1 image will look exactly the same size as the 40mm lens. What you have to realize though is that the minimum focus distance is not the issue, the ability to focus to 1:1 is.įor example, 1:1 means life size, so a 1/2" bug would cover 1/2" on the sensor, as if it were placed directly on the sensor.Ī 40mm macro lens (Nikon AF-S 40mm) with a 1:1 ratio might have a close focus distance of say 6", with that 6" providing the 1:1 ratio. If it is the current lens, Sigma says 12.3" for a 1:1 macro ratio.
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