BioImages - Notes on Digital Camera

The following relates to the Nikon Coolpix 995, long out of production and is really only of historical interest.

A digital camera is a valuable (in both senses!) fieldwork tool. It is a convenient, quick and cheap (once you've bought it) way of recording information which would otherwise require time-consuming sketches. Nowadays, when I find anything unusual a quick photograph of the locality enables the spot to be easily refound.

I use the Nikon CoolPix 950 digital camera. This has a good macro facility. Even with the digital zoom turned off (digital zoom has no conceivable purpose beyond conning naive shoppers) the subject area will go down to 17mm wide. You have aperture control to stop down for increased depth of field.

The controls and viewfinder screen are in one half of the camera and the lens, flash and viewfinder lens in the other. The two halves rotate about a central pivot. This takes a bit of getting used to. It is very useful in some situations eg taking shots above your head, low down and parallel to the ground, or close-ups in the middle of a clump of nettles. Less useful is the invisibility of the viewfinder screen in sunlight or bright conditions, but this is actually less of a problem than you might expect. It may be the British weather, but there have only been a few occasions when this has troubled me. The problem seems to be with a very bright sky rather than direct sunlight itself.

For some reason, in portrait mode the viewfinder screen seems to become washed out and the pictures likewise, although this doesn't always happen.

The menus allow you to quickly switch colour temperature when the sun goes behind a cloud and you can measure it ("white preset") using a sheet of paper for unusual conditions (eg under trees) or when you want to be precise.

The colours are reasonably good, although rather contrasty, even with "reduce contrast" set. Blues are overemphasised: skies come out Mediterranean, orchids are bluish pink and bluebells turn out pure gentian but these are all easily corrected in PhotoShop. (Pinky blue flowers are notoriously unreliable with conventional film too.) Wet leaves also seem to reflect blue with the CoolPix.

A set of rechargeable batteries lasts about as long as it takes to fill a 48MB card. That's using the LED viewfinder and not hurrying, but a second set of batteries and a second charger is a must. The 48mb card holds 50 to 60 images at the "Fine" setting which is 1600 x 1200 pixels, stored as JPG.

The auto-focus has the problem of all auto-focuses: it focuses on what it wants to focus on, not what you want! You can lock the focus by half pressing the shutter, although this also locks the exposure. It's useful to have a piece of neutral grey card to hold behind flowering grasses etc to force it to focus on the right subject, then half press the shutter, remove the paper and take the picture. You can select manual focus, but this doesn't allow maximum close-up and the viewfinder window is too small to see if it is in focus so you have to use a tape measure.

I always use a tripod with the Nikon. I used film cameras for years, even doing close-ups up to x5 without a tripod, but I can't with the Nikon, except for snapshot-type pictures. There are just too many fiddly controls to use and the waist-level viewfinder is cumbersome for handheld close-up work. Also, I've practically stopped using flash. For insect photography, film is more convenient to my mind, though I've had good pictures if the insect is still and against a solid background that the autofocus can latch onto.

The camera and its software seem to make no allowance for the gamma setting of the computer. Gamma relates to the brightness curve. A linear gamma (1.0) means that pixel values of 128 will correspond to 50% grey. PC's are generally set to a gamma value 2.2 while Macintosh users use 1.8. The result is that PC pictures look washed out on a Mac and Mac pictures look overly contrasty on a PC. For web work, Mac users generally adopt the PC gamma setting. The CoolPix apparently ignores all this, except that I find the pictures very contrasty on my Mac with the PC setting...

The above text relates to my own personal experience and is offered in good faith. It does not constitute a recommendation.