I have had more than one person ask me about macro photography recently and today I had the opportunity to work with two very nice macro lenses along with my passable camera lenses.
Macro photography refers to images that are recorded at least 1/4 life size on the image sensor. This allows for standard 4x6 prints to be made that are life sized or larger. Some cameras and lenses will even specify the macro capabilities in a numeric fashion. The best lens I own for macro photography gets down to a 1:2 ratio which means that the thing I am taking a picture of is recorded on the image sensor I am using (in the old days this would have been film) at 50% of the real life size. Given the high density of pixels on modern image sensors this means the image can be enlarged up to several times life sized. I will discuss each lens I used for each of the pictures in testing
To make all of these images I adjusted the focusing manually to the closest focusing distance each lens was capable of. Once I had adjusted the focus I moved the camera until the subject was in focus. This shows the capability of the lens at the most extreme of settings.
To start with I will show pictures shot with a Nikon 105mm Macro lens. I seriously lust after this piece of glass as it is nice and bright and I can't say that I have used many sharper lenses. The biggest downside to this fantastic lens is the limited amount of depth of field you get when working close with your subject. The benefit is that you can move back from your subject a little bit to let more light reach whatever it is you are trying to photograph. The following three photos were shot at f4.8 (note the almost non-existant depth of field), then f11 and finally f25 (which could still use more depth of field to make me totally happy).
Now for comparison, here are a set of photos shot with my non-macro 28-105mm f2.8 lens. This is the main lens I do most of my shooting with but you can see here how it just doesn't stack up to a dedicated macro lens for getting crazy close detail. Just one picture at f2.8 followed by one at f16 so you can see the difference aperture makes when you are standing back a bit.
The lens I typically use for macro photography is my 70-300mm lens which cost approximately 1/4 of the previous lens. I have always been happy with the results I get from this for the price and it's easy to see why you want different lenses for different jobs. Something to note with these pictures is the way the shape of the mushrooms (or whatever they technically are) flattens out a bit. As the focal length gets longer this effect becomes more pronounced. Another impact is that it is easier to get light in the image as you have to stand back further to get these shots. The main downside of the longer lens is that camera shake becomes more apparent and you really need a stable tripod. These shots were done at f4.8 and f22 respectively.
Here are two more shots from a dedicated macro lens. This one was a 60mm lens and also very difficult to get close enough to show off the close focusing ability. I had to get even closer with this lens than I did with the 105mm macro. You can notice the difference in the lighting a bit as well as the shape of the mushroom getting a bit more round. I thought I shot one with the lens wide open but I guess I missed that one. These shots at f13 and f 29 should give you an idea of the changes. You will notice that the impact on depth of field is slightly less pronounced than with the longer lenses. This holds true in general as focal length gets shorter.
The final two sample shots I have were taken with my point and shoot camera. The first I shot in the regular macro mode and the second one is in the magnifying glass mode. The first thing that jumps out is the difference in colour quality. This is part of what you pay for with an SLR over a P&S camera. The other thing that should jump out at you is how wildly different the perspectives are with these two shots when compared to the photos from the SLR. This difference is because the focal length of a P&S camera is much shorter than the focal lengths I used to test the photos.
That's a lot of sample pictures to take in so I'm going to just number off a few quick points of macro photography: 1) a dedicated lens can get much closer than a multipurpose lens 2) as you get closer to the subject and/or use a longer focal length you end up with less depth of field 3) as your focal length gets shorter the subject distorts more 4) doing macro photography without a tripod requires insane amounts of light
The assignment for this class is to grab your favourite lens, manually adjust the focus to as close as it will go and move the camera till your subject is in focus. The only restriction with the subject is that no flowers or bugs are allowed. I figure that people should be able to send me some images by the end of the month without too much trouble.
Just because bugs are lots of fun, here are two shots of the same dragonfly. The first one was shot at 300mm and the second was shot using the magnifying glass mode on my point and shoot camera. It's very easy to see the difference in perspective and depth of field between these two lenses.
All of the images in this lesson may be clicked on to view larger.