To a camera, the typical scene is 18% gray on average. That’s just what photography experts decided represents the typical landscape shot. This generally works well for landscapes, but can cause problems shooting lighter objects like flowers.
Shooting a close-up of a pale flower therefore gives you an 18% gray flower, not a luminous shot of your subject. This is easy to fix, since you can simply adjust the exposure in your image editing software to make things bright again.
Shooting a pale flower against a dark background is not so simple. The camera will likely completely overexpose the flower, eliminating fine details from the petals. This can’t be fixed in image editing; you have to get it covered in your camera. There are three ways to do this, starting from the simplest:
- Use your camera’s exposure compensation setting to underexpose the flower.
- Use spot metering to get a reading from the flower and not its background.
- Use manual exposure settings to underexpose the flower, with a bit more control than using exposure compensation.
Check your image with a histogram to make sure you’ve captured everything. If you’re off, the histogram data will extend off one or both sides of the chart. Some cameras have spot exposure warnings that flash in the playback screen to indicate areas that can’t be captured with the current settings.
If your camera has a RAW setting, this can sometimes extend the range of tones that you can successfully capture. The down side of this is you’ll get larger file sizes and will have to fine-tune your photos in image editing software compatible with your camera’s RAW files.
If you’re using a phone, well maybe it’s time to get a real camera. Phones don’t have much dynamic range, optical zoom is rare and setting their cameras manually can be complicated to set up and use. Phones are fine for plant ID (most of the time) but if you want something to display and enjoy, a camera will give you better results!
Bush Anemone (Carpenteria californica) Evergreen shrub.
This is a classic example where the image had to be corrected after shooting to restore brightness to the flower without losing the details in the petals.
Leaving the flower a bit less than white better shows details of the petals’ veins.
California Buckeye (Aesculus californica) Deciduous shrub/tree
These flowers are against a dark background, so exposure had to be checked to make sure petal details weren’t washed out.
Cream cups (Platystemon californicus) Annual wildflower.
Another blend of light flowers and darker details.
Bird’s Eyes (Gilia tricolor) Annual wildflower.
This macro shot exposed for the lighter portions of the flowers, letting the deeper colors fall where they would.
Some more tips for shooting flowers
- Shoot a lot of pictures of each flower or composition. The better you think it is, the more shots you should take. Since flowers rarely hold still, this lets you choose the photos with the best focus.
- Depth of field – what’s in focus – is controlled by your lens aperture, or f/stop. Bigger numbers mean more depth of field, but they also reduce the amount of light hitting your camera’s sensor. Often, larger apertures (lower f/stops) give more artistic effects with parts of the flower in sharp focus and the rest a more impressionistic blur.
- The only ways to compensate are to use a longer exposure time or increase your camera’s light sensitivity, or ISO. Each of these things has its disadvantages: longer exposure times can create blur in your images. Sometimes it’s artistic, sometimes not. Increasing ISO can lead to increased image noise, at some point reducing the quality of your image. This tends to be increasingly noticeable in darker areas, especially if you lighten them with software.
- If you’re in nature, there’s often a fair amount of wind, making precise focus difficult and blurring shots taken with longer exposure times. I tend to shoot both maximum aperture (low f/stop number) and stopped down (high f/stop number) versions of the same flower or composition, so I can choose what worked later. Waiting for a lull in the wind and timing the shot can work, depending on conditions (sometimes the flowers never stop moving).