To take a point-and-shoot camera, you need the camera itself (apparently) and film. And it was while choosing the film that I realized that I needed to understand a little about what ISO, exposure, aperture and shutter speed are. So let's figure it out together. Let's start with ISO.
ISO <TAG1> is one of the key parameters in photography that determines the sensitivity of a sensor or film to light. In the past, notation was used ASA, but the principle remained the same.
What is ISO?
ISO (Inational Organization for Standardization) – is an international standard that defines the sensitivity of a digital camera or film sensor. The ISO standard for photography was implemented in 1974, combining the previous ASA (American) and DIN (German) systems. ISO allows photographers to easily adapt to different lighting conditions by changing the sensitivity of the camera.
What is ASA?
ASA (American Standards Association) – is an old film sensitivity measurement system that was used in the US until the 1980s. It was similar to modern ISO: for example, ASA 200 is approximately equal to ISO 200. In parallel, the DIN system was used in Europe, which worked on a logarithmic scale.
Why did you switch to ISO?
The transition to ISO took place to unify world standards. Prior to ISO, various countries used ASA, DIN or other systems, making international use of photographic technology difficult. Thanks to ISO, photographers around the world have received a single, understandable standard of sensitivity.
Unification is good. We can now see a similar transition to USB-C (Type-C) on all new gadgets.
What is the ISO indicator responsible for?
In film photography, ISO (ASA) determines the chemical sensitivity of a film. A high value means that the film reacts faster to light, but at the same time the pictures are more granular due to the structure of light-sensitive elements.
What happens if the ISO sensor and ISO film are different?
One of my cameras (Kodak Cameo) has an ISO switch. So you need to understand how this setting works.
Kodak Cameo
If ISO 200 is installed on the camera and film 200 is used
The camera correctly exposes the frame according to the sensitivity of the film. A balanced exposure is obtained (we will consider what exposure is below).
If ISO 400 is installed on the camera and the film is 200
The camera "thinks" that the film is more sensitive than it really is and selects the settings according to ISO 400. This will lead to unexposed frames (dark) because the film 200 needs more light.
Such a film can be "pulled out" during development/scanning, but the grain will increase.
If the camera allows you to set the correct ISO manually —, you need to set what is indicated on the film. If not — should understand how it will affect exposure and how it can be compensated for when manifested.
Usually, "soap boxes" have a fixed ISO, so the film must be selected accordingly. And you need to take pictures with the appropriate amount of light.
What exactly are the numbers 100, 200, 400, etc. responsible for?
These values indicate how sensitive the sensor or film is to light. When increasing the ISO by half (for example, from 100 to 200), half the amount of light is required to obtain a correctly exposed image.
ISO 100-200 <TAG1> for sunny weather
ISO 400 <TAG1> for cloudy weather and shadow shooting (indoor)
ISO 800+ <TAG1> for shooting in low light conditions, but with a noticeable grain in the photo
What is exposure?
Exposure (Exposure) – is the amount of light that hits the sensor or film during shooting. It determines how bright or dark the image will be. The exposure is controlled by three parameters: ISO, diaphragm and endurance.
Re-exposed frame <TAG1> too much light, the photo is very bright, there are illuminated areas.
Unexposed frame <TAG1> too little light, the photo turns out to be dark, the details in the shadows are lost.
What is a diaphragm?
Diaphragm (Diaphragm) – is a hole in the lens through which light passes. It is measured in f-numbers (for example, f/2.8, f/5.6, f/11). A smaller number means a larger hole and more light:
Wide aperture (f/2.8, f/1.8) <TAG1> more light, blurred background (good for portraits)
Closed aperture (f/8, f/11, f/16) <TAG1> less light, more detail in depth (good for landscapes)
What is endurance?
Endurance (Shutter Speed) — is the time the camera allows light to hit the film or sensor. When you press the button on the camera, a special mechanism (curtain) opens and the light gets inside. The longer it stays open, the more light is captured.
Short exposure (eg 1/1000s) allows you to capture fast moments like the movement of a car or athlete. Long exposure (eg 1s or more) allows you to shoot in the dark or create effects like water motion blur or light trails from machines.
These are the basic things you need to know (in my opinion) before buying the first film/camera. So I hope someone will find this post useful.
