Study your target species
Read as much about each species as you can, so you know where to look for them, and how they behave at different times of the day. Most species bask to warm up early in the morning. Courtship and copulation usually take place in late morning. Nectaring is easiest to observe and photograph in the afternoon. Many species roost openly on foliage as dusk approaches. Each species however has its own timetable and its own preferred habitat. Learn beforehand and you’ll get better photos.
Set your camera up correctly
Set up your camera in advance so you have a fast enough shutter speed to freeze movement, and a small enough aperture to obtain good depth of field. This generally necessitates an ISO setting in the 200-800 range. Using spot focus is usually faster and more accurate than zone or full area options. Using Program mode will free you from decision-making and let you concentrate on composition, but Aperture Priority or Shutter Priority modes will give you more flexibility.
Take essential accessories
Often you’ll find that your view of a butterfly is obstructed by a stem or grass blade, so carry a pair of small scissors to trim them away. Instead of carrying a cumbersome camera bag just carry your camera and macro lens around your neck, and use a pocket for accessories. Always carry a spare fully charged battery, a spare memory card, a lens cloth, and a waterproof plastic bag to protect your camera in the event of rain. Carry water if you are going to be out for more than an hour.
Wear suitable clothing
White or pale clothing makes you highly visible to butterflies and makes it much harder to approach them without scaring them off. Wearing shorts and t-shirts makes it more likely that you’ll be bitten by insects or scratched by thorns, so wear long sleeves and long trousers. Using knee pads and/or elbow pads will make it more comfortable to crawl around on stony ground. Wear a hat to avoid sunstroke.
Choose the right lighting conditions
Butterflies are easiest to find on hot sunny days but that is generally the worst time to photograph them. They will be easier to approach and more likely to bask in cloudy weather, weak sunlight or when temperatures are low in early morning or late afternoon. Shooting in harsh overhead sunlight will bring out the textures on the wings, but shooting in overcast conditions is better if you want to bring out subtle colours.
Use flash to fill-in shadows
Shooting with the sunlight coming from the side makes the photo look more 3-dimensional, but can cause ugly shadows that need to be lightened by the use of fill-in flash. Note that most cameras fire a pre-flash a fraction of a second before the main flash, and this causes some species e.g. skippers and satyrs to take flight. You can overcome this by using manual flash but you will need to take a few test shots to establish the correct exposure.
Approach carefully
Pre-visualise the photo you want to take, then approach the butterfly slowly and steadily, avoiding any sudden movements. Be careful not to cast your shadow over the butterfly. If you have difficulty approaching nervous butterflies, shoot from further back with a long lens, but you’ll have a wider choice of angle and will probably get better shots if you use a 90-100mm macro at closer distance – it just takes a bit of practice.
Choose the right angle
To get photos that are sharp from wing tip to wing tip you need to keep the camera sensor parallel to the wings of the butterfly. If you shoot from an oblique angle you will need a smaller aperture of about F16 to keep the entire butterfly in focus. Shooting from various angles adds variety however and stops your photos from all looking the same.
Watch the background
Fussy backgrounds and out of focus raindrops are very distracting, so compose your photo to try and keep the background uncluttered. Don’t overdo it though, as very plain backgrounds can make it look as if your photos were taken in a studio instead of a wild habitat.
Leave space around the butterfly
A very common mistake is to get too close and completely fill the picture with the butterfly. Usually you get a nicer photo by stepping further back and including some of the surrounding vegetation – it helps to place the subject in context with its habitat. Shooting from further back gives you more options to recompose and crop your photo when you download your images to your computer.