November 7, 2002 / Photography / Winter 2002

Digital VS. Traditional Cameras

Written by David Stedwell


Figuring the Final Size
How big the image will be in the yearbook should guide the choice about whether to use film or digital capture. Many medium-priced ($500-$1,000) digital cameras when set at their highest image quality will produce good printed images that are 6 in. x 8 in. or smaller. Full-page photos need the higher resolution of film to provide good quality, especially in color.

Getting the highest quality possible out of a digital camera image requires the same technique that produces good film images — fill the frame. Select the correct format and distance to the subject so that none of the image area is wasted.

Searching for Shallow Depth of Field
Photographers who have come to rely on blurred, shallow-depth-of-field backgrounds to highlight a center of interest are in for an unpleasant surprise when they switch to digital cameras. The combination of optics and the small size of the digital image-capture chip hinder the kind of shallow depth of field available with the simple twist of the aperture ring on 35mm film cameras.

All cameras will produce their shallowest depth of field if the focus is on a subject at close range. The only other option for digital camera users is to soften the background areas with a computer program like Adobe Photoshop.

Finding the Wide Angle
Once again, the optics and digital image-capture chip in the digital camera conspire to prevent the type of true, wide-angle lens images that photographers rely on for a different perspective when working close to subjects, and for showing wide views at a distance.

When the assignment calls for a wide-angle lens, it is time to switch to the 35mm film camera and its relatively inexpensive wide-angle zoom or fixed-focal-length lens options.

Avoiding a Blackout
Automation has brought a host of added features to both film and digital cameras, unfortunately at a price—batteries. Some film cameras suck the life out of batteries, but few even come close to the power consumption of digital cameras. The problem is that both the image-capture chip and the screen display use power. That is a lot of power and, at up to $12 a battery, a lot of cash to keep capturing images.

Never leave home without a spare battery, and spend the extra money for rechargeable batteries. The batteries and the charger may seem pricey up front, but they will more than pay for themselves after a few assignments. Turning off the screen display and using the viewfinde r to compose images will save power. Since the display screen is the most power-hungry feature on the camera, save the casual review of captured images for the computer screen.

Waiting for the Shutter
Digital cameras behave very much like film cameras in most respects, but one of their quirks, the capture delay, leaves even the most experienced camera handlers shaking their heads.

Unlike film cameras, when the shutter release is pressed on a digital camera there is usually a slight delay before the image is recorded on the chip. The result can be a blurred image caused by camera movement. Some manufacturers have solved this problem by providing an electronic shutter sound when capture is complete. Most others require the photographer to keep attention focused on LED signal lights inside the viewfinder.

Once the image is captured, there may be a second delay while it is being stored. That prevents a second shot until the first is safely transferred from the chip. Higher-priced digital cameras solve both problems by shortening or eliminating the delays and by allowing several shots in a quick burst.

Photographers using digital cameras need to understand the delay quirks of their particular camera and practice shooting to get a feel for the time delay after the first shot and before the next one.

Seeing the Light
Digital cameras may be a way out of the darkroom, but digital photographers may be left in the dark when lighting is low. The traditional techniques of pushing film speed and switching to a powerful electronic flash are simply not options with most digital cameras. Their image-capture chips do not have the sensitivity to light available in films, and they cannot be pushed to greater light sensitivity than their 80-400 ISO equivalent. To add to the low-light challenge, most digital cameras still do not provide for the addition of a standard electronic flash to boost the light output of the tiny in-camera flash.

When the assignment calls for low-light images, especially night football and indoor sports action, the best option is still a 35mm camera with a fixed-focal-length telephoto lens and film with an ISO rating or 1600 or 3200. When electronic flash is needed to light a wide area or carry a great distance, the 35mm camera and a supplemental flash again should get the assignment.

This photo was made with a Nikon COOLPIX 880 digital camera at its highest JPEG format setting.

The trick to getting a high-quality yearbook reproduction of this image lies partly in the photography and partly in Adobe Photoshop.

Select an image-quality setting for the digital camera with enough pixels to allow for image quality at the desired reproduction size.

The camera used to make this image has several image-quality settings. The one selected provided enough pixels to allow for a 9.1 in. x 6.8 in. image at a resolution of 225 pixels per inch (ppi).

Fill the frame with the elements you plan to use when the image is reproduced. Selecting a small area of a digital image and then trying to enlarge it results in poor reproduction quality. Too many pixels are wasted in cropping and there are too few left for a quality enlargement.

By moving in close to this subject with the lens set on wide angle, the optical zoom produced an image similar to a 38mm lens on a 35mm film camera. Although the angle of view is not particularly wide, the relationship of the lens focal length to the size of the digital capture chip made it possible to work close to the subject and still get good depth of field.

Size wisely in Photoshop. Most digital camera images appear as JPEG files with a resolution of 72 ppi when they are opened in Adobe Photoshop. When working with an image in this program, the trick is to retain all of the pixels captured by the camera even though the resolution and the size of the image need to be changed.

This image opened in Photoshop as a JPEG file with a resolution of 72 ppi. When the Image Size dialogue box was selected from the pull-down menu under Image, it also revealed that there were a total of 2048 x 1536 pixels in the image and that it would convert to a size of 28.4 in. x 21.3 in. If a yearbook printer wants digital photo files with a resolution of at least 225 ppi, how can the resolution be changed without losing image quality?

First, make sure the Resample Image box is not checked. That allows Photoshop to make changes in resolution without changing the pixels contained in the original image.

Second, change resolution first, and then determine the new image size with all the pixels retained. When the resolution of this image was changed from 72 to 225 ppi with Resample Image turned off, the new size was 9.1 in. x 6.8 in. This new size is the maximum reproduction size without loss of quality.

David Stedwell