Butterflies

by Markus Ehrenfried 

Taking pictures of butterflies in the field is normally extremely difficult. Usually these insects are very active and you constantly have to pursue them. You might have hardly focused and they will move slightly as if they would know exactely how to get outside the area you've focused on -- and often the butterfly will be just gone when you're finally ready to shoot. Some time ago I visited the Alaris Schmetterlingspark near Buchholz, approx. 40km south of Hamburg. This is sort of a 'zoo' for tropical butterflies. Basically it's a big greenhouse, heated up to 30°C, with a humidity close to 100%. There must be thousands of butterflies inside and they seem to know that they easily outnumber the few human visitors. They are not the least bit scared of you. When you stand still and look closely at a butterfly (it will not fly away, even if you almost touch it!) others will just sit down on you. You can feel the soft flapping when they fly just centimeters in front of your face. I didn't expect them to be that confiding. When I bought my ticket at the entrance the woman at the cash desk pointed to a potted plant on the table and said: 'This is already the first butterfly'. I didn't see a butterfly at first. Than I realized that this huge brown thing was indeed a butterfly. 'It's a nocturnal moth, it's sleeping now'. Even with its wings together it was almost as large as a postcard.

When you enter the greenhouse your lens will instantly fog. It's useless to wipe the condensation away, it will fog again within moments. You have to wait until the glass reaches ambient temperature, then the condensation will disappear by itself. The outside temperature was around 18°C, inside the greenhouse it was about 30°C. I was surprised how long it took, I had to wait for almost an hour until I could take the first picture. There is absolutely no artificial light, the only light filters in through the frosted glass roof and it is very dim and diffuse, at least on an overcast day. Probably I should go there once again on a bright and sunny day. They don't allow the use of flash units. What a pity.

I chose an ISO 400 film, but even with this film I had to expose almost all the time between 1/60s to 1/90s and at f/2.8. I had no tripod with me and it would have been difficult to set one up anyway as the pathes between the tropical plants are extremely narrow and you would block them for other visitors. Therefore I expected the pictures to be blurred and out of focus due to camera shake and lack of DOF. I was quite surprised that most of them turned out much better than I had hoped for.

At f/2.8 the DOF of my Canon 100mm Macro lens is close to zero. If you're interested have a look at the DOF table. Then the only thing you can do is to be not too ambitious and try to work at 1:1 magnification but recede a bit and gain DOF in the order of 1mm. That means that a tiny slice of the space in front you, just 1mm thick, will be in focus. It is critical that you align the film plane e.g. exactely parallel to the wings of the butterfly. But even then, you probably will not manage to get the whole butterfly in focus as the wings are not totaly flat but slightly angled. Well, that's just the geometry of a butterfly  ;-)  and you can see e.g. in the picture above that the area next to the body is in focus but the outer regions become less and less sharp. Without flash or faster film there is not much one can do about that. Here is another example which shows the extremly limited DOF:

The good news is, that the butterflies there have not to work hard to find food and survive. There are no enemies and predators. Most of the time they sit somewhere relaxed and enjoy their good live. That gives you enough time to focus carefully and they won't even fly away if you get really really close.

Recently hatched butterflies are pinned to plants; they have to wait until their wings are rigid enough, but as soon as they can fly they seem to be pretty hungry.

Next time I'll go there on a bright and sunny day. As no flash is allowed I'll perhaps take some reflecting foil with me and -- just in case -- some ISO 800 films.

-- Markus Ehrenfried