How to use high ISO and low ISO?

In this photography tutorial, we will study when we need to set a higher ISO and when we need to set a lower ISO. For any photographer, it is very important to adjust ISO as part of exposure.

ISO is a measure of the sensitivity of camera sensors to light. The lower the value, the lower the sensitivity; the higher the value, the higher the sensitivity.

First, low ISO

In the case of sufficient light or tripod, it is a good choice to choose a lower ISO (for example, below 400), and the style of photos taken will slow down the shutter speed. Under the low ISO setting, the sensor of the camera is not sensitive to light, so more light is needed to create a well-exposed photo.

From a technical point of view, using a lower ISO can get a better quality photo with little or no digital noise, and the color and overall contrast of the photo will be better.

Second, high ISO.

When shooting in low light and cannot be exposed for a long time, it is best to choose high ISO. A high ISO indicates that the camera's sensor is more sensitive to light, which means that less light is needed to create a well-exposed photo.

From a technical point of view, this also means that the image may be affected by digital noise, the color will not be saturated, and the overall contrast is very poor. The intensity of the impact depends on the selected ISO and your camera model.

Technology changes with each passing day. If you have a newer camera model, you can safely choose a high ISO value.

Third, when will ISO be adjusted?

Unlike shutter speed and aperture, ISO settings have no direct creative effect on photos. If you think that the existence of digital noise is creative and can simulate film particles, then I suggest you take a closer look at this topic.

The ISO setting will help you get the required shutter speed and/or aperture setting.

Fourth, the use of ISO and aperture.

If you want to blur the background by opening a large aperture when the light is bright enough, you should set ISO to one of the lower values. If you want to use a high ISO, combined with a large aperture, you won't get a good exposure, so the background won't look as soft as you think.

On the other hand, if you want to create an image with all elements in the composition clear, you'd better choose a higher ISO value, especially in the case of poor light. By choosing a higher ISO value, the aperture can be set to a higher F value, thus obtaining a greater depth of field.

Verb (abbreviation for verb) ISO and shutter speed

If you want to create a motion-blurred photo, choosing a low ISO will make your shutter speed slower. If you want to take pictures, such as waterfalls with smooth flowing water, you need a lower shutter speed.

Freezing at a fast shutter speed usually requires a high ISO, especially when the light is not very bright. Being able to use such a fast shutter speed that it is impossible to freeze usually means striking a balance between exposure and high ISO.

Six, automatic ISO

If you want the camera to control the exposure, you can use ISO in automatic mode. If ISO is set to Auto, the camera will automatically adjust ISO while adjusting the aperture and shutter speed.

If you choose to work in "Automatic ISO" mode, it is recommended that you conduct some tests and find the appropriate ISO limits.

Therefore, please take a series of photos with the same theme under the same lighting conditions, double the ISO each time, and then compare the results to find the image with strong noise.

Even in automatic mode, many cameras can set the maximum ISO value. Therefore, you can set the value obtained from the test.

conclusion

When you want to achieve a certain effect or change the lighting conditions, you need to adjust the ISO value.

If shooting outdoors on a clear day, the ISO will be between 100 and 400. If you enter a room, especially in dim light and with many windows, you may find it difficult to get the correct exposure at a fast enough shutter speed.

By adjusting ISO, the camera sensor will be more sensitive to weak light, thus becoming more flexible and creative.