NATIONAL7Spotlight Weekly)]

Faster Focus

Put a faster film in your camera, and get sharper pictures

By AKSHAY SHARMA

It seems that ISO 400 (the speed of the film) color-negative film is quickly becoming the choice of amateur photographers. This film speed provides a great combination of image quality and increased f-stop/shutter-speed capabilities. It performs well in most any given situation.

"For many years, the standard film was ISO 100 and the increased grain and contrast, and decreased image sharpness discouraged photographers from using higher-speed color-negative films. The higher-speed films were used only as a last resort when light levels dropped and the slower films just couldn't do the job," says Mahesh Maharjan, a professional photographer.

Today new film technologies make the ISO 400–800 films as good as the ISO 100 films. Since the bulk of today's images never is enlarged beyond 4x6 inches, film of any speed would do an adequate job.

"The two basic principles of photography, namely f-stop and shutter speed, are directly affected by this increased film speed. It may not seem like much of a change from ISO 100 to ISO 400, but this two-stop increase can make a definite improvement in your photographic images," explains Dilip Bajracharya of Dilli Bazar's Bajra Studios.

Sometimes it is tough to get everything you desire in focus. A higher film speed allows you to select a smaller aperture, which creates a greater depth of field. What most photographers often don't realize is that the extended focus range is not proportional on either side of the focus point, say experts.

"The ratio is actually 1/3 between the camera and subject, and 2/3 beyond your subject. As you step down your aperture to compensate for the exposure increase due to the higher film speed, your focus extends twice the distance beyond your subject. This allows you to focus on subjects close to the camera and still keep the area in the distance sharp," says amateur photographer Manish Sherchan.

Era Gharti, a graduate of Moscow's School of Photography, explains: "This is a great advantage when photographing a large group of people at varying distances. For example, with a 35mm lens and ISO 100 film, a depth of field from 4–7 feet increases to 3–12 feet when you switch to ISO 400 film and stop the lens down accordingly. That is quite a jump in depth of field considering that image quality changes very little. If you use ISO 800 film, the depth of field extends from 2.5–20 feet at the same focused distance, thanks to the ability to shoot at the next smaller aperture. Of course this is assuming that your subject motion is under control and you are only changing the aperture to accommodate the change in film speed."

Says Sunil Bhatwal, who owns a camera shop in New Road: "Point-and-shoot cameras have become very popular, but they generally have small internal flash units with limited distance range. With a higher-speed film, the flash in your camera can pack a bigger wallop. Here’s how it works. If your flash has a maximum distance of 8 feet with ISO 100 film, it can be extended to 11 feet with ISO 200, 16 feet with ISO 400, and 22 feet with ISO 800. This is why so many one-time-use cameras are loaded with ISO 400 or 800 films."

Era explains: "You will find that using higher-speed films will be an advantage if you own a more advanced camera system with an external flash. With higher-speed film, the scene doesn't require as much light to achieve a good exposure, so the flash will shut off sooner, recycle faster, thus saving battery power."

"Often when using long lenses, you don't have full sunlight, and you require more depth of field than is available with the lens aperture wide open. If you change films, the two or three extra f-stops may be all you need for success. If you still think that you must use ISO 100 film with your long lenses, you must ask yourself if you would rather have a grain less blurry image or a sharp image with slight grain when enlarged," is Era's professional advice.

If we lived in a perfect world, then ISO 100 film would be the film for every photo situation. But we all know that photo opportunities arise where ISO 100 is inadequate. What you need to realize is that when you grab the higher ISO films, you are not compromising quality, but rather taking control of the situation. This allows you to devote your concentration on image aesthetics, rather than technical issues.