Film was mostly sensitive to green light, and pinky reds recorded as black, and greens as bright tones. In most normal scenes though pictures record with a moderate contrast that makes a nice change from the over blown black and white work that is widely popular among enthusiasts.

There are two principle ways of creating a conversion using just the green channel – you either isolate it by deleting the red and blue channels, or go into a channel mixer tool to effectively turn off all but the green. Either method delivers much the same result.

Green channel conversions are great for all sorts of subject types, but I especially use it for portraits and city scenes when I want pictures to appear older than they really are.

As digital cameras has twice the number of green pixels as either red or blue you will find that green channel conversions present the absolute best you will get from your camera. Resolution and image detail is optimised, and image noise will be at its lowest.

Filters V channels

If your camera has a black and white mode you may have wondered whether it is better to shoot using this mode and coloured filters over the lens, or whether to shoot in colour and convert using a colour channel mixer or selector in software. You may find that most people will tell you that essentially the two methods add up to the sdame thing, but that one involves putting a piece of glass or plastic over your expensive lens which might degrafe your image quality. Actually there is a difference, though it is quite a subtle one.

If we compare digital processes to the days of film shooting with filters is just like when we shot with black and white film and filters, but when we use channel mixer tools it is like changing the characteristics of the film. Digital sensors are panochromatic – that is, they are sensitive to red, green and blue light. When we use a single channel by itself we are effectively altering the sesnitivity of the sensor. Using only the green channel makes the sensor behave as orthochromatic film, and using only the blue makes the sensor xyxy. When you put a filter over the lens you are still using a panochromatic sensor but you promote one colour and hold back another. The effect is quite different, as is the principle. Using a filter over the lens with a panochromic sensor will always produce a more extreme result, that can only be matched in magnitude in software by extensive manipulation that degrades the image.

This picture was taken using the Olympus E-3.

To see more of my pictures
visit my photo galleries site
at www.damiendemolder.com

This is a fairly simple idea for making macro or close-up shots more interesting and more unusual. I know I have spent ages in the past trying to get close to bugs and insects to show just how ‘macro’ I can get. In the end though I often created pictures that were only interesting from the point of view of being close to a small object – rather than pictures that are visually stimulating in their own right.

For this shot I didn’t get as close as I could, but concentrated instead on getting a nice picture. Using this low angle I was able to create a brilliant blue background using the sky. It also makes the shot striking in the first instance because we are not used to seeing Daddy Long Legs from this angle. Looking up at the subject in this way the viewer gets the impression that the insect is a giant – its a bit War of the Worlds.

On this occasion I set the camera to aperture priority mode and was able to shoot away without needing any exposure compensation. If the sky had been any brighter or darker I may well have needed to adjust the exposure by half a stop or so. Shooting with ISO 400 might not be best for ultimate picture quality, but it allowed me to combine a small aperture, for extensive depth of field, with the short shutter speed I needed to combat the effect of the wind blowing the flowers around.

On balance it’s better to accept some image noise to create a sharp image. Had I shot at ISO 100, for example, I would have been forced to use a shutter speed of 1/125sec – which would not have been short enough to freeze the movement of the subject. The shot didn’t need any post capture work, other than to add the touch of Unsharp Mask that all digital files require.

The camera I used was a compact with a flip-out articulated screen so it was easy for me to shot from this low angle and still see what I was going to get. I have shot the same sort of thing with other models as well though, without the flexibility of this type of screen – you just have to rely on guess-work and shoot a few more pictures to get the result you are looking for.

Shot with an Olympus Camedia C7070WZ – exposure 1/500sec at f/11. ISO 400 with the zoom set to the equivalent of 55mm.

If you use a DSLR, or a film SLR, and don’t have a flip-out vari-angle screen like the C7070WZ has you could use an angle finder like the one shown here. This makes it easier to see through the lens when in awkward positions. Many camera manufacturers have their own units, but this one, sold through Kauser International, is designed to fit many different cameras via adapters.

To see more of my pictures
visit my photo galleries site
at www.damiendemolder.com

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