How will changing the ISO setting on my SLR change the actual image?

Question

I shoot using 400 ISO *FILM* in a Yashica FX-3 camera and I've heard people shoot at different settings other than using 400. How much would I need to compensate with the light meter?

What if I set it lower? I'm trying to figure out different ways to use film other than what I'm doing now.

Answer 1

The ISO setting and the light meter together determine the shutter speed. If you use 400 film and set it higher the camera will think you're using a faster film and decrease the shutter speed, so you will be underexposed. If you set it lower the camera will think you're using a slower film and therefore it will be overexposed. This can be very useful if for example you have a brighter object which is "fooling" your light meter - you can deliberately overexpose that object so that you capture the background. I'm afraid you're going to have to use some film to see what it does exactly!

Answer 2

An image is formed by the lens...as determined by its focal length, f/stop, abberations, and other characteristics. The quality of the image remains the same despite ISO, chip capacity or any other manipulation device. The file, however, of that image changes with the manipulation. The ISO or speed of the capturing device, be it film or chip, is a measure of how fast it can capture the image in a given timeframe. The better the device, the more information it can capture, store and reveal about the image. By increasing the "speed" of the capture medium, you are decreasing the time it takes to capture all the information possible. Unfortunately, there are practical limits to speed as determined by the quality of the medium and the availability of light from the subject. "Faster" settings (IS0 400 for example) generally yeild lower quality captures compared to optimum settings (ISO 100-200). If the subject is moving, you may opt for freezing it in time using the fastest settings. But if the subject is still, lower speed settings generally result in higher quality pictures (views or prints of the captured image). As the photographer, you make the creative decisions to achieve desired outcomes.

Answer 3

the iso shows how sensitive the film is to light - the higher the number...the more sensitive it is

for example...if you were to shoot long exposure with only the full moon for light, you would need to use a very high iso film so as to pick up as much light as possible from the lack of light there is-

if you are going to shoot in direct sunlight, then you do the opposite and use iso 50 or 100

the only problem with using a high iso number is that it becomes very grainy and so is hard to do long-exposure pictures without noise

hope that helped

Answer 4

If you set the ISO setting to 100 when you have 400 film in it will over expose the image.
A favourite trick of mine was to underexpose slide film which means the colours would be deeper..
Faster film does tend to have the "grain" further apart to enable higher shutter speed. so images will show this when printed.
Also if you change the ISO rating on a film then you have to change the development time so if you have them developed by a lab inform them you have changed the ISO setting.

Answer 5

the higher the setting the grainer the picture, but this allows for less light to still take the photo.