High ISO does NOT cause NOISE! (but f/Stop & Shutter do!)

Summary

In this video, the speaker challenges the misconception that high ISO causes high noise in images. Through a series of tests, they demonstrate that short shutter speeds, high f-stop numbers, and low light are the actual culprits behind increased noise, not high ISO. The speaker emphasizes the importance of using ISO as a tool to manage exposure, similar to a speedometer, and suggests ways to reduce noise by increasing light, adjusting shutter speed, or using faster lenses. The video also highlights the advantages of mastering exposure techniques over simply upgrading camera equipment.

Takeaways

• 😀 High ISO does not inherently cause more noise in images.
• 😀 Brightness in high ISO images is due to increased sensitivity, not noise.
• 😀 Adjusting the brightness in post-production can normalize the exposure without adding more noise.
• 😀 Short shutter speeds tend to introduce more noise than high ISO settings.
• 😀 High f-stop numbers (smaller apertures) also contribute to increased noise in an image.
• 😀 Low-light conditions result in more noise, not high ISO settings themselves.
• 😀 The actual cause of noise in images is often less light hitting the sensor, not ISO.
• 😀 ISO can be thought of as a 'speedometer' for light sensitivity, not a direct cause of noise.
• 😀 Improving image quality can be achieved by lowering ISO or increasing light through other settings (shutter speed, aperture, etc.).
• 😀 In low-light scenarios, adding light (e.g., through a flash, or changing camera settings) is often a better approach than just increasing ISO.
• 😀 The speaker's curriculum on digital photography offers a structured way to learn about camera settings and techniques for better image quality.

Q & A

How does high ISO affect image brightness?

High ISO causes images to be brighter. This is because increasing the ISO sensitivity boosts the sensor's ability to gather light, resulting in brighter images in low-light conditions.

Does high ISO cause more noise in images?

In this example, high ISO does not cause more noise. The high ISO image actually has less noise because the camera uses a dual gain sensor that helps mitigate noise at higher ISOs.

What effect does short shutter speed have on noise in an image?

Short shutter speeds increase the noise in an image. When brightness is adjusted to equalize exposure, images with short shutter speeds show significantly more noise.

How do aperture settings impact noise levels?

High f-stop numbers (narrow apertures) increase noise in an image. Like short shutter speeds, narrowing the aperture reduces the amount of light hitting the sensor, which results in higher noise levels.

What role does lighting play in image noise?

Low light conditions result in more noise in an image, even if other camera settings are the same. More light hitting the sensor leads to cleaner images with less noise.

What are the common factors that cause high noise in images?

Short shutter speeds, high f-stop numbers, and low light conditions all contribute to high noise in images. These factors reduce the amount of light reaching the sensor.

How should ISO be viewed when considering noise in photography?

ISO should not be blamed for noise. Instead, think of it like a speedometer, indicating how much light your sensor is receiving. The real causes of noise are factors that limit light, such as low light conditions or settings that reduce light exposure, like short shutter speeds and high f-stop numbers.

What can be done to lower noise without changing ISO settings?

To lower noise, you can adjust other settings like using a slower shutter speed, lowering the f-stop number, using a faster lens, or adding more light to the scene using a flash or other lighting techniques.

How does adjusting auto ISO help improve image quality?

Adjusting auto ISO can act like a speedometer, showing whether you're providing enough light to your sensor. Lowering ISO by one stop effectively doubles the amount of light reaching the sensor, which can significantly improve image quality, even matching the performance of a full-frame or medium format camera.

Why was ISO considered the cause of noise in the film days?

In the film days, ISO was tied directly to the film's grain. High ISO film caused noisy, grainy images because the film itself had limited light sensitivity. In modern digital cameras, ISO no longer directly causes noise in the same way, since the noise is more related to other factors like light exposure and sensor technology.