When doing close-up and macrophotography a constant consideration is how much depth of field is appropriate to the subject. For my taste, I enjoy having a reasonable subject definition while keeping a good background separation.
I first started doing macro photography with a film camera and, when I switched to digital, I noticed I had more depth of field than before: One gets more depth of field when sensor size decreases. I also had more apparent magnification because my 105 mm Micro Nikkor now behaved like a 150 mm lens due to the 1.5 crop factor of the DX-sized (APS-C) sensor.
Before I keep writing I must say the convention is that close-up photography is called macro when the subject is imaged at or beyond its own size in the sensor. This means that a one-inch (25 mm) long bug filling the long side of an APS sensor (24 mm) is at about 1:1 reproduction ratio and thus is “macro.” However, and here I don’t quite like the convention, the same bug reproduced at 1:1 on an FX (36 mm long) sensor will not fill the frame and yet should also be called “macro.” In a medium format sensor (about 44 mm) our 1:1 bug’s image would only use up about half of the frame, and so on. Each of the uncropped prints would show our bug in three different, progressively smaller sizes (and we didn’t consider 8×10 inch film yet!). The larger format sensor or film prints will actually look like just a “close-up” …and it will be hard to see the bug in the 8×10″ camera’s print, even if it is letter-sized.
Because of this, I prefer to call photography of 20-30 mm (about 1″) sized subjects like insects or individual flowers “macro” and photos of groups of flowers or mushrooms “close-ups.”
For photos of small subjects, one is forced to choose larger f/numbers. Otherwise, not enough of the little bug is sharp enough to look pleasant to the eye. Flowers could be more forgiving as the colorful, out of focus areas often look very nice. Large f/ numbers demand lower shutter speeds and very quickly one needs to use a tripod or a flash, especially inside a forest.
I love doing macro with small sensor cameras like the CX sensor found in the Nikon 1 system and some compacts because one can achieve enough depth of field at f/4 or f/8 to get a nice image. You basically gain two f/stops of depth of field relative to an FX (24 x 36 mm) sensor camera. For this comparison, your f/stop on a full frame camera would be f/8 or f/16 and your subject would look far smaller in the frame at the same 1:1 magnification.
Some time ago I helped a friend to choose a micro four thirds system for her underwater photography. One of the lenses she got was the Olympus M. Zuiko Digital 60 mm f/2.8 macro lens and I just fell in love with this small, powerful lens. Now, a few years later, I decided to get the lens along with a Panasonic Lumix GX85 camera: It turned out to be a great combination!
The in-body image-stabilization (IBIS) of the Lumix, coupled to the smaller f/numbers needed by the micro four thirds sensor allowed me to take photos effortlessly without using a tripod. The lighter camera allowed me to hold it steady at arm’s length in order to to reach through the vegetation for more distant subjects.
This is my first forage into micro four thirds photography. I love it so far. I don’t think I will “make the switch” because I need to make big landscape prints and for this my Nikon D810 camera is much better, but I am very impressed with my tiny new camera and from now on it will have a place in my bag, …or in my coat’s pocket!