At least one field guide I own promotes butterfly photography to be more accessible to the average person than bird photography because the equipment is much less expensive. Technically that is probably true, and I have read some threads which suggest that inexpensive digital point and shoot cameras are popular among butterfly observers. Certainly they are convenient to carry, and some have good zooms. At the upper end they may be fast enough as well. However, many bird photographers are migrating over to shooting butterflies, and I am confident most of them use single lens reflex (SLR) camera systems with interchangeable lenses to shoot bugs, and such systems are all relatively expensive. With shrewd shopping at online auctions or used camera shops, one could probably pick up the basics for under $800, and with practice and patience make some excellent images. There are several brands of equipment to choose from, all of them capable of doing a good job. Your choice should be based in part upon your needs, the lenses and accessories available for a brand. For some quirky reason many photographers are intensely brand loyal, so be aware of bias when asking someone for advice.
The camera: I use two camera bodies for my photography, both digital SLRs, one reasonably professional, the other consumer. Both feature autofocus, which is often very useful for bugs. The professional body is also more ruggedly constructed. On one camera I mount a long zoom lens and on the other a macro or close-up lens. Very functional consumer models are available for well under $1000. For our purposes they will lack only the more durable construction, some 'write' speed, and possibly accessory connection terminals.
The long lens: In 35 millimeter film SLR photography the lens designated as 50 millimeters (mm) is considered to render the image the same size it is in life, or 1X. The '50mm' is the distance between the film plane and the objective lens. In most digital format SLR cameras you can expect any lens to magnify the image by about 1.5 times beyond it's stated length. Generally I use a 70 - 200mm lens which equates to 105mm - 300mm in magnification, or 2 to 6X life size for bugs and birds. It has the ability to focus about 4 feet from the subject. This lens gives me two advantages; it magnifies the subject to fill a good percentage of the film frame, and it gives me adequate working distance to prevent the subject from flying off. The lens itself has a maximum aperture of f/2.8 throughout the zoom range, and it is designed accept teleconverters. Teleconverters will magnify the image by an additional 1.4X and retain the same minimum 4 foot focusing distance. The zoom lens with image stabilizing technology allows these lenses to be successfully hand-held as slow as 1/250 second, but you are pushing your luck with the converters at that shutter speed. Lenses that combine all these features are made for the professional market and retail for about $1600.00 or more, much more. They are magnificent tools. Converters are $300 to $400 each, and will reduce your maximum aperture from 1 to 2 stops of light, depending upon the magnification. By-the-way, you will also want to remove the flower-shaped lens hood if you are using pop-up flash to avoid an unwanted shadow in the bottom of the frame.
The 70-300 lens: This consumer grade lens is an excellent option for photographers with fiscal restraint. Similar lenses are made by several manufacturers. It is light weight, with close focus of under 5 feet, excellent glass, anti-shake technology, and about $400 - $500. One downside, and you will not notice with flash, is a variable aperture, which changes with the zoom ratio. It makes an excellent travel lens as well.
The new guy on the block, the 18-200 DX lens. This lens is fairly new, and may be hard to find. Here is a consumer lens in the $600 range, designed for Nikon digital cameras, that zooms from 18mm (film equivalent 27mm) to 200mm (film equivalent 300mm) , with all the stabilizing technology, high quality glass and fast focusing engine of its professional cousins, AND focuses throughout its incredible zoom range to 20 inches! For many this is the only lens you may never need another - for anything. But, it is variable aperture, does not accept teleconverters, and is a little slower than I would like.
The macro lens: This lens in its various incarnations is design to magnify the image and allow the lens to get close enough to the subject to recreate the actual size. So, you may will see lenses advertised with reproduction ratios of 1:1 or 2:1. The first would be actual life size; The second would magnify a small object to twice its life size in your image. One challenge in using these lenses is getting close enough to make them effective. In Cech and Tudor's superb Butterflies of the East Coast, one of the authors is depicted using this method, and the inference is that all the shots were taken that way.
A second obstacle is the naturally very narrow depth of field afforded by these lenses. That is a good thing for the most part since it will set your subject apart from the background. But the closer you get the less depth of field there is, and you do want to include as much as possible of your subject in focus. For that reason experienced users often shoot these lenses from a tripod using slow shutter speeds and stopping down to a small aperture to increase depth of field and get absolutely sharp photographs. Not practical for moving targets like butterflies.
You will notice in the caption above that I have used a 105mm lens. They are in the $500-600. If you really get serious about microphotography, you may wish to invest in a 180 or 200mm close focusing lens, giving you 6X magnification at 20 inches. You will, however, have to part with about $1500. This is a world unto itself.
Let there be light: Because the subjects move at will, I hand-hold most of my butterfly shots. As a general rule 300mm is the practical maximum length lens for shooting hand-held, and that requires a very fast shutter speed – in excess of the reciprocal of the lens length (1/300 second or faster). Often enough ambient light is not available for these shutter speeds, so most bug photographers employ a camera mounted flash unit. The camera is set to shutter mode, at its highest synchronized flash speed, usually 1/250s (1/500s in the Nikon D70), in order to compensate for camera shake. The aperture will automatically adjust to maintain a correct exposure - in this case wide open to allow for sufficient light. This will also pleasantly blur the background. This technique, called fill flash, reduces unwanted shadows on the subject, and leaves the background naturally lit. Consumer digital SLRs have a pop-up flash which is pretty good for this process. Photographers for whom shooting butterflies is a serious pursuit would ideally use a ring light on the front of the lens or off camera flash on either side of the camera or lens for even lighting. Very short flash durations, measured in 1000ths of a second, will freeze the image at any shutter speed. But, this is only true if the artificial light source (flash units) override the natural light source.
When using my D200 for butterflies I almost always employ a flash unit on auto FP synch, at 1/500 second shutter speed with any lens and shoot in manual mode to set my apertures to f/8. This will give me a well exposed subject unless there is a great deal of ambient light. In that case, these settings would overexpose the subject.
Summarizing equipment: I don't think I am going out on a limb by suggesting that the ideal equipment for butterfly photography is a digital SLR, with a very quick response time and a large, fast memory card. Instead of the pop-up flash you will want to mount one of today's very sophisticated digital flash units which have an almost instantaneous recycle time when used as fill flash (about $300). A further advantage with these flashes, and today's newest digital SLRs, is a technique called auto focal plane high speed synchronization. Using this method, you can use flash at as fast a shutter speed as you wish. The disadvantage is the limited distance of the flash at the higher shutter speeds. Not all digital cameras have this capability. Another option is the newest line of paired flash units mounted on either side of your lens, ($500) giving excellent light at close quarters, and no overexposure , a problem with conventional flash units at very close range.
Technique -There is no substitute for knowing your subject. That is a mantra I repeat in seminars and as a general answer to questions. You will need to know where, and when to look, as well as the habits of your subject. Many butterflies simply will not hold still for any period of time, and represent a huge challenge.
Let me illustrate with an example: There is a bug, presumably on my home island, called a Juniper Hairstreak. I have yet to see one, let alone photograph it. It is found in Eastern Red Cedar trees in coastal habitats. First, I need to look there, obviously. Hopefully by whacking enough Red Cedars I will force a colony to take flight. Once I actually find them, the next difficulty will be to get a camera up to their height, or patiently stake out the colony until one drops to my level. Finally when all else is in place, I will will have to carefully approach the subject, with the sun at my back, staying as low as possible to minimize a looming threat to the butterfly, struggle to keep my shadow from encroaching over the butterfly, and then making the determination to use flash, if it is quiescent enough, or if it is very active and fluttering, to turn off the flash, switch the camera to which ever mode will give me the fastest shutter speed based on ambient light, and then fire off bursts at up to 5 frames per second. All that is real world butterfly photography.
Ideally I can identify the bug and photograph it in its natural surroundings. At times that does not happen. I find the most effective way to study a new bug, photograph it, and then release it unharmed, is to capture it. I put it in a jar, or preferably a glassine envelope to restrict its movement and prevent damage to its wings. Then it goes in the refrigerator for about an hour to slow its metabolism. I can now study it carefully to learn the nuances of identification. Hopefully this chill will also allow me an extra moment to shoot it before it flies. I try to release it in a similar habitat to that in which I found it. I need to be already set-up for this, because in summer weather the insect will warm quickly and be gone. There are many butterfly watchers who disagree with this method, and I accept that criticism. And yes, on rare occasions I will loose one, but my objective is to leave a well focused and composed photographic record of the butterflies in a particular geographic area. I might add it has been suggested that more butterflies are killed by collisions with automobiles than have ever been collected, so the occasional loss of a bug with a 2 week or 2 month life span does not particularly bother me. On the other hand, if and when I come across something rare, I have to re-visit this approach.
Fortunately many bugs will hold fairly still without human interference, so much insect photography can be conducted without risk to the subject. Long lenses, used as described above, have inherently shallow depths of field, so the photographer must be constantly aware of keeping the plane of the film as parallel as possible to the subject. Portions of even a relatively flat subject can easily be thrown out of focus, ruining the shot. Your movements should be restricted and slow, and your shadow, cast over the subject, will spook it every time. Whereas we are taught to always focus on the eye in photography, with bugs you will want to focus on the diagnostic characteristics of the insect, hopefully fully outstretched dorsal and ventral wing patterns.
Below are shots of a 2.75 inch model of a Cuban Bee Hummingbird. It is representative in size of many butterflies, and it won't fly away. The shots, all centered on the eye, serve to illustrate how large an image you can expect from the discussions above. Each shot was taken with camera mounted flash using a tripod. And yes, sometimes you can actually be too close to find your subject
Processing images: The shots above are used to illustrate the difference in magnification at selected focal ranges. In fact, when you process your images on your computer you will almost always crop your images to a pleasing size and composition. This is one of the view reasons I can think of to give credence to megapixel wars. The higher the resolution of your camera, the more you can theoretically crop. A poor exposure will be a poor exposure in any event. This article is not designed to go into any digital darkroom detail. Speaking of which...
If I have to proselytize one brand name in these paragraphs, I will. Adobe Photoshop. Okay, you can get some of the same processing power at a much lower price with the consumer product Photoshop Elements. Photoshop is the standard image processing software in the industry. Period.
Your comments are welcome.