title- How ISO Affects Mobile Photos

Understanding ISO: How it affects mobile photos

When it comes to taking photos with a mobile camera, I’m a big advocate of shooting in manual mode for very good reasons that I won’t get into in this article. But one of the big reasons is because of the amount of control it gives you.

Among the settings you can control in the manual mode such as shutter speed, white balance, metering modes, and more, you can also adjust the ISO.

If you’re new to photography and know absolutely nothing, then that probably means nothing to you. At least for now. In this article, we’ll look at ISO and what part it plays in mobile photography.

What is ISO?

The acronym ISO stands for International Organization of Standardization. It is a setting found on digital cameras that can adjust the brightness of a photo by boosting the electronic signal gathered from the light that struck the camera’s image sensor.

ISO is usually expressed as a number starting at 100 and doubling in brightness as it increases to 200, 400, 800, etc. The more you increase the ISO value, the brighter the picture will be. And because of how it can brighten a dark image, ISO also forms part of the exposure triangle.

To better understand ISO, let’s look at its origins in the world of film photography.

Film ISO

Back in the days of photography on celluloid film, ISO referred to the level of the film’s sensitivity to light. The value of measuring the film’s sensitivity usually began at 100, then went up to 200, 400, 800, and so on. The higher the value, the higher the sensitivity to light.

film rolls

So, if you were shooting outside in bright light, you’d pick a 100 ISO film roll because of its low sensitivity to light.

On the other hand, if you were shooting indoors with reduced lighting conditions, you’d opt for a 400 ISO film roll or higher, understanding that the film is more sensitive to light than an ISO 100 roll.

Digital ISO

When the world moved over almost entirely to digital photography, the standard for measuring ISO remained the same. The lower the ISO number, the less bright the image will be.

The only difference is that instead of physically replacing an entire film roll to get the ISO you want, ISO can now be increased and decreased digitally because it’s all just an electronic process inside the camera.

A common way to think about ISO is as a measurement of the sensor’s sensitivity to light. However, to be more accurate, the sensor has only one sensitivity level when activated.

ISO can, therefore, be seen simply as a calculation of how bright the final image should be based on the base input exposure you set.

Base ISO and Common ISO values

The base ISO is the lowest native ISO setting on your smartphone’s camera. On most devices, this number is set to 100 although some go as low as 50 ISO.

It’s important to try to stick to the base ISO to ensure you capture the best quality pictures. That’s because shooting at base ISO means little to no visible digital noise.

Of course, it’s not always possible to shoot using base ISO. Here is a common set of ISO values found on many mobile camera apps:

  • ISO 100 (low ISO)
  • ISO 200
  • ISO 400
  • ISO 800
  • ISO 1600
  • ISO 3200
  • ISO 6400 (high ISO)


Every mobile camera app is different and may, therefore, have its own set of ISO values that are different from the typical ones above.

Even though a lot of smartphone cameras only go up to 6400 ISO, some can go even higher. In fact, the Huawei P30 Pro is said to go all the way up to an unbelievable 409 600 ISO.

Whatever the ISO values are on your mobile camera, what you need to remember is that when you double the ISO value, you double the brightness of the image. You need to be careful, though, because there is a trade-off for increasing the ISO. More on that later.

Where do you find ISO on a mobile camera?

To find your camera’s ISO setting, you need to switch to the Manual mode of your camera app, also known as Pro mode on some devices. The ISO setting is fairly easy to find because it is usually labelled by name.

ISO control in manual mode

If your camera app does not have a Manual mode, then you should definitely download one that does. Being able to manually control settings such as ISO can definitely change your photography for the better. That’s actually one of the reasons why you should shoot in Manual mode.

If you’re not familiar with Manual mode and all the settings in there, then check out this complete and comprehensive guide to manual mode.

How does ISO affect the image?

As already mentioned several times, the higher you set the ISO value, the brighter the image will be. Thus, ISO can be beneficial when shooting in low light environments. 

However, in bright environments, it’s best to keep the ISO as low as possible to avoid overexposure.

the effects of ISO on exposure

Another unfortunate thing is that the higher you go up the ISO scale, the more digital noise you’re bound to introduce to your image. This will deteriorate the quality of your photos.

Every smartphone camera has its own signal-to-noise ratio. This means that different cameras have different thresholds at which noise becomes apparent and degrades the image.

more ISO means more noise

You can learn more about what digital noise is and how to fix it here.

Raising ISO vs. Editing the brightness a photo

Because ISO basically brightens up an image that the sensor has already captured, many people may believe that brightening up a photo on a computer or a mobile app is the same as increasing the ISO on a camera.

While both methods do brighten an image and make digital noise more apparent while doing so, the image quality tends to be better when the brightness of an image is increased in-camera by pumping up the ISO than cranking up the brightness in an editing app.

Remember, when a mobile camera takes a picture, it goes through a processing pipeline in the camera’s image signal processor or ISP. Part of this process is noise reduction, where an algorithm is applied to the image to reduce the amount of digital noise.

Thanks to this system, the ISP will, to some extent, reduce the amount of noise that comes as a result of increasing the ISO. Brightening the image in post will not yield the same results.

In other words, you could get better picture quality from your mobile camera if you take a shot at 800 ISO than if you take a photo at 100 ISO and then brighten it up by a whole lot later when you’re editing.

When to use high ISO

As mentioned before, you should aim to stick to the base ISO as often as possible to ensure you get minimal noise on your images.

This is provided there is ample lighting available such as outside during the day. In these conditions, you are free to set the ISO as low as possible to minimize the appearance of digital noise.

You can still use a low ISO in low light if you wish to do so by increasing the shutter speed to brighten the image and thus keep the ISO low.

However, you will have to use a camera support system to keep your phone steady otherwise your photo will come out looking blurry. A tripod is a popular option that also comes in portable sizes. Also, your subject should preferably be motionless.

When to use high ISO

Even though its best to shoot with a low ISO, sometimes you have no choice but to increase the ISO level. This is the case when you’re trying to avoid motion blur.

See, the downside of increasing the shutter speed is that it introduces more and more motion blur the longer the sensor remains exposed to light. So, to take a sharp image of fast-moving action, you need to capture the image using a fast shutter speed.

Because this will result in a much darker image, you have no choice but to increase the ISO. And that’s the bottom line: increase the ISO when you have no other way to capture a sharp, bright image.

How to maximise image quality with minimal noise

So, if you want to brighten the images you capture with your phone, you need to increase the ISO yet doing so might introduce digital noise in your images. Is there a way to work around this?

Luckily, there are a few ways to minimize the amount of digital you get when increasing the brightness of a picture using ISO. These options rely on adjusting camera settings, hardware, and editing.

Exposure triangle

The best way to get good image quality with minimal noise is to familiarise yourself with the exposure triangle.

Getting good picture quality from setting the right exposure on your smartphone camera means striking a good balance between the ISO and shutter speed settings. Unfortunately, the aperture is fixed on smartphone cameras, so you can’t change it to further adjust the exposure.

If an image appears dark, before increasing the ISO, consider adding extra lighting. This could come from a lamp, an external smartphone flash, or even an open window during the day.

Having extra lights will illuminate the scene more and eliminate the need to crank up the ISO more than necessary, and thus avoid unnecessary digital noise.

Megapixels and sensor size

A large contributing factor to how high you can set your ISO level before you start noticing digital noise is the size of the sensor and the pixels on it. A camera with a large sensor and large pixels is more likely to be capable of reaching high ISO levels before introducing noticeable digital noise.

That’s because small pixels are more likely to display digital noise. Large pixels are not. And the only way to have bigger pixels on a smartphone camera is to equip it with a larger sensor.

And because all the bits and pieces that make up a smartphone camera are so small, the size of the pixels, and not how many there are, is what matters most when it comes to digital noise and the quality of mobile photos.

So, if you look up the specs of your phone’s camera specs and realise that they are not at the same level as the specifications of what qualifies as a good smartphone camera, you might have to constantly deal with dark photos that get noisy the more you increase the ISO.

If you’re serious about doing mobile photography, the best thing to do in this situation is to get yourself a phone (new or used) with good enough specs to take decent pictures.

This doesn’t even have to cost an arm and a leg. There are some pretty low-cost smartphones with some decent cameras on them. Check these out.

If smartphone cameras with lots of megapixels are your thing, have a look at these phones of 2020 that have the highest megapixel cameras so far.

Noise reduction

If you found yourself in a situation where, despite having tried everything you could, you still found yourself having to crank up the ISO to a speed that introduces noise, don’t worry too much. There’s still hope.

Even after a photo has been taken, you can reduce the amount of noise in the shot by bringing the photo over to the preferred noise reduction app or software of your choice.

Keep in mind that there is a limit to how much noise reduction you can apply to an image. So, you need to be careful with using noise reduction in post-processing because too much of it can ruin a photo.

This is because noise-reduction software usually just smooths out the noise by blending and blurring pixels and not by actually removing it completely. So, if you overdo noise reduction, you could end up with an airbrushed look on your photo that makes skin texture look unreal.

Therefore, when using noise reduction software, practice caution and use it in moderation keeping in mind how you’d like the final image to look.


So, as you can see, ISO is a blessing in the way it can add more brightness to an image when the lighting in a scene is low.

But it can also be a curse because of how digital noise becomes more visible the higher you set the ISO. Therefore, you need to find a good mid-point.

Every smartphone camera is different. So, what you need to do is experiment with the ISO on your mobile camera and see how it affects images on your phone. See how far you can push it in different lighting conditions before the quality of the photo starts looking bad because of digital noise.

Once you’ve seen and understood how it works, learn something else about your phone’s camera. By doing so, you will know your camera better and know how to get the most out of it in order to take awesome photos.

And, did you know? It’s possible to make some extra money online with your mobile photos. It’s true! And the higher the quality of your images, the more you stand to make.

If that’s something you’re interested in, I can help you better your chances of succeeding. Check the link below.

free ebook download link

If you want to learn about how to improve your smartphone photography, download the 5 Ways To Improve Your Smartphone Photography ebook by clicking on the banner above or by clicking here. There’s a lot to learn in its 22 pages of content and it’s ABSOLUTELY FREE!!!

Otherwise, for some quick tips on how to capture great photos with your phone, check out these 15 Tips on How To Take Amazing Photos With Your Phone.

Leave a Reply