A short while ago I wrote a tutorial on how to photograph insects. That essay was focused on using a digital SLR, and shared a lot of material with an earlier essay that covered insect photography using a film SLR. (The digital SLR essay is in this blog, click here to see it.)
To round things out, I was planning to write an essay on insect photograph done with a ‘prosumer’ digital camera. By that I mean digital cameras with a built in zoom lens, that, unlike digital SLR’s, won’t allow the user to change optics.
I’ve used a Nikon Coolpix 990 for insect photography for several years, and while this camera has seen a lot less used in the last couple of years (since I started using the Pentax *ist-D digital slr) it still accounts for a disproportionate percent of what I would consider my best insect shots.
All of the photographs that appear in this essay were taken with the Nikon Coolpix 990.
So while I originally planned to write about using prosumer digital cameras for insect close-ups, I realize that would be over reaching. I only have experience using the Nikon CP990, and given the vast array of digital cameras available, its hard to say how relevant that experience is. So, I’ll limit my remarks to the CP990, and if they are relevant to other digital point and shoot cameras, great. If not – I hope you enjoy the pictures.
Working with the CP990 for insect closeups is completely diffferent than working with an SLR – film or digital. Here’s a summary of the major difference between the two platforms:
● Distance to subject: The CP990 has to get very close to the subject to get a full frame shot, and the smaller the subject, the closer the camera has be. How close? In the essay on photographing insects with the Pentax *ist-D, I demonstrated a full frame shot of a fishing fly taken at a distance of abbout 12 inches. To fill the frame on the CP990 with the same fly, the camera has to be about 1.5 inches away. That’s close!
You’d expect that having to get that close to the subject would result in most of them getting scared away. This can be a challenge but since you are able to hold the camera away from your body (see the point below) its not as much of an issue as you might expect. I guess a relatively small camera coming in towards a bug is less threatening that a large camera held at eye level by a person.
To get this close, the camera must be set to macro mode. Many prosumer digicams have a close up mode, and some more useful than others. If your camera does not have a closeup mode, you can try using close up filters or reverse mounting a 50mm lens (from a 35mm SLR) onto the lens.
● Handling of the camera: Working with the Coolpix 990 is a totally different experience than working with an SLR. This is true for many prosumer digitals. Since you can use the LCD to compose the shot, you are liberated from having to keep your eye to the finder. This means that you can get shots anywhere that you can reach.
A few days ago I commented on being unable to photograph a black damselfly that had flow higher and higher as I approached it. Had I been using the Coolpix it would not have been a problem – as long as it was in reach I could have gotten the shot.
Here are two examples where this kind of camera handling has come in handy. In the case of the Eastern Tailed Blue (‘Lil Blue’) above, the insect had worked its way into a cluster dense vegetation. I was able to snake my hand, with the camera, in after it. Because the distance between the butterfly and the camera was so small (the butterfly was less and an inch in size) I was able to postion the camera free of any intervening branches from the plant. As a result, using the Coolpix resulted in an insect photograph that simply would not have been possible using an SLR.
This blye dasher dragonfly is another example of a shot that would have been impossible with an SLR. In this case the dragonfly was up high, perched on a very tall plant stalk. I’m over 6 feet tall and can easlily reach up to 8 feet or so, but I was standing on my tip toes to get this shot. If it had to hold the camera at eye level to use a finder, I would have need to bring a ladder to get this!
● Depth of Field: This term refers to the area within the photograph that appears to be in focus. As you move in for a close up, the depth of field gets smaller. Without going into the mathematics, this is because depth of field is a function a magnification. The more you magnify your subject, the less depth of field. Depth of field is increase by working at smaller aperture sizes – the more you stop down, the greater the depth of field. Of course – the more you stop down, the less light that passes through to the camera, and the longer the shutter speed.
This creates the classic problem for macro photographers. It’s always a struggle to get enough depth of field to get the critical elements of the subject in focus, while maintaining a shutter speed fast enough to freeze the action of the subject.
Fortunately the Nikon Coolpix 990, and other prosumer digitals, do very well in regards to depth of field. The reason is because these cameras use a very small sensor to record the image. For example, the sensor in the Coolpix 990 is approximately 7 x 5.5 mm in size – a mere fraction of the size of a 35mm film frame (35 x 24 mm) or of the ‘APS’ sized sensors in digital SLR’s (about 22 x 15 mm).
Because the sensor is so small, the subject is magnified less, and the depth of field at any given f stop is much greater. The result is that images taken at f8 or f11 have a DOF comparable to f 16 or smaller on an SLR. This means that you can shoot with the lens more open, enjoy a faster shutter speed, and also be able to retain a usable amount of depth of field.
But, this can be both a blessing and a curse. On one hand its great to be able to get a close-up with the whole subject in focus, and the increased depth of field is a real boon for very small subjects shot at very close distances. On the other hand, if you want to isolate your subjects by throwing the background out of focus, the tremendous depth of field in prosumer digitals can become a hindrance. In insect photography this is especially the case for larger subjects – like large butterflies or dragonflies – where the degree of magnification of the subject is very small, so the depth of field extends out for long distances. Here is an exampleof a shot were the backgroun - though quite far away - just never got burred out. Though the shot is acceptable, the distracting background is a real detriment.
● Image Quality: My Nikon Coolpix 990 is a pretty old camera (introduced about 6 years ago!) Since it was introduced, digital camera manufacturers have made huge advances in image quality, improving the color accuracy, decreasing the noise levels, increasing sharpness, and increasing the range of light the camera can capture. Despite its age, I’ve be consistently happy with the results of the Coolpix 990 at ISO 100. (At higher settings the amount of digital noise becomes a problem.)
Just like the sensor size affects depth of field, there are some aspects of image quality that are also affected by sensor size. For example, the sensor in the CP990 has about half the number of pixels as the sensor in my digital SLR, but the physical size of the sensor is about on third of that in the SLR. Obviously, this means that the individual photo sensors in the Coolpix are smaller and packed more tightly.
This physical aspect of the sensor has two effects on image quality, both of which are observable. For one thing, the small sensors can resolve more detail. In typical shooting situations, the advantage of being able to resolve more detail is wasted, simply because the lens is projecting such a small image onto the sensor, there isn’t a lot of detail there to be captured. But when shooting macros, with very high magnification and relatively simple subjects, this ability to capture detail is a great boon. My Coolpix, for example, seems to be much better at resolving the individual cells in insects compound eyes, compared to either film or my digital SLR.
On the flip side, the smaller sensor size usually results in increased noise. More light hits the larger individual photo cells in larger sensors, and so the signal (amount of light) to noise (amount of background interference) ratio is greater. The camera’s microprocessor can better figure out what is noise, and what is the actual photograph, and the result is a much less noisy image.
So in terms of image quality there is a real trade off, between the improved detail and resolution in the prosumer digital vs the increased noise. Personally, as it applies to insect photography, I’ve been satisfied with the results of the Coolpix 990, and suspect that more modern digicams will produce much better images still.
● Lighting: The ability take control over lighting is a key element in most forms of photography. When shooting static subjects, this can be accomplished with diffusers and reflectors. When shooting dynamic subjects – and nothing is more dynamic that insects on the wing – this usually calls for flash.
Unfortunately, I see this as the Achilles’ heal of the prosumer digital camera for insect close-ups. When using an SLR, the working distance between the subject and camera makes it relatively easy to use a flash to illuminate the subject. As noted in the earlier essay on insect photography with a DSLR, when using a 200mm macro lens and focusing in on an insect just 1 inch in size, the working distance between the front of the lens and the insect is approximately 1 foot. When shooting large butterflies or dragonflies, 2 or 3 feet of working room is the norm. This room make it possible to position a flash in the best place possible to illuminate the subject and close background.
The very small working distances of a prosumer digicam greatly complicate the use of flash. For the smallest subjects, those within just an inch or two of the camera, its almost impossible to squeeze in the light of a flash at an angle that works. The problem is not so pronounced with larger subjects, but even then you are working with inches of space vs. feet.
That’s not to say that it can’t be done – it’s just that the working distance makes it more complicated. Personally, I never setup a flash system for the Coolpix 990, and instead relied on diffusers or my own shadow to soften the light enough to get a good shot. I also would shoot on days where the natural light was bright but diffuse – high overcast days. Sometimes this resulted in shots that were too flat, but often times just using the diffuser worked well:
That stands in stark contrast to the SLR world, where you have great flexibility in flash setup. For example, I shot this image on film using a dual macro flash setup – a 75 / 25 % power ratio between two flashes positioned to the left and the right of the lens. It was an unagainly and awkward system – something I ultimately quit using in the field – but it remains an option due to the working room afforded by SLR setups.
I think this covers the main aspects of my experiences with the Nikon Coolpix 990 for insect ph
otography, and how they compare to using an SLR. In any event, as mentioned at the start of this essay, some of my best insect photgrafy has been accomplished with the CP 990, so if you have a prosumer digital on hand and are interested in shooting bugs, by all means make use of it. With the right technique, it should produce first rate images.