This time of year tends to slow down my progress whenever I'm outdoors; my wife, it seems, can't pass a flower without taking a picture of it on her phone. Indeed, no matter what kind of camera you own--SLR, compact, or smartphone--spring is a great time to take photos of flowers, insects, and other small details of the natural world.s--
You can get some really nice close-up photos (technically referred to as macrophotography) with almost any camera by remembering a few rules. So what do you need to know?
For starters, every camera lens has a minimum focusing distance. You can't cheat the laws of optics; get too close to your subject, and the result will simply be blurry. The iPhone, for example, has a minimum focusing distance of about 2 to 3 inches. That's great, especially since you don't need to do anything special to trigger close-up mode.
Many compact digital cameras, on the other hand, won't automatically focus once you get within a foot or so of your subject. In order to take a macro photo just inches away, you'll need to turn on the camera's macro mode, which is usually a button or menu setting with a tulip symbol. The macro mode rearranges the camera's optics to focus very close up, but remember to turn it off when you're done--a camera in macro mode won't be able to focus sharply on subjects that are at a normal distance.
Depth of field
The biggest difference between taking macro photos and ordinary portraits and landscapes is the depth of field you have to work with. Depth of field is the region in your photo that's in sharp focus--usually some distance in front of and behind your primary subject. In a typical family portrait in front of a rose bush, you have a depth of field of several feet, which lets you get both the people and the bush in sharp focus (even if you weren't really thinking about depth of field to begin with). In other words, depth of field in ordinary photography can be quite forgiving.
In shooting the Lilliputian world of flower petals and ladybugs, though, depth of field might be measured in inches--or a fraction of an inch. That's not much.
If you have an SLR or a full-featured compact camera, you can maximize your depth of field by using your aperture; larger f-numbers (like f/16 or f/22) give the biggest depth of field. If you have a phone, though, or a camera that doesn't let you dial in an aperture, then you're stuck with what you've got. One other thing to try: If your camera has scene modes, try the one called close-up or macro. It'll set the aperture for as much depth of field as possible. Either way, this much is true: The closer you get to your subject, the smaller your depth of field will get, and when you're only a few inches away, don't be surprised if the depth of field is just a fraction of an inch, no matter what you do.
One solution to this quandary is to compose the photo with a small depth of field in mind. If your subject extends from the front of the scene all the way into the background, you're virtually guaranteed that part of the photo will be blurry. But if you change your perspective and shoot the photo so it's perpendicular to the camera lens--all the same distance from the camera--then depth of field is far less important. You can capture it all in sharp focus.
Watch the shake
At these distances, a little camera shake can look like an earthquake. It's always a good idea to put your camera on a tripod or some other sort of support, and that's doubly true when shooting flowers and bugs from a few inches away.
And yes, you can even get a tripod for your iPhone or other smartphone. I like the $30 GripTight Micro Stand from Joby, for example.
Finally, it helps to think a little about lighting. Direct sunlight is not especially flattering for close-up nature photos, in part because you'll end up with variations of light and shadows in the scene. You'll get better shots with indirect lighting--that means photos shot when the sun is behind a cloud, or when you can get the scene in the shade. If you're headed out specifically to take nature photos, you can carry a large piece of poster board or a collapsible reflector to place between the sun and your subject. Or you can just try to take the shot early or late in the day, when the sun isn't directly overhead. Either way, you'd be surprised how much better your photo can look when the sun isn't beating down directly into your scene.