How to Choose the Best ISO for Night Street Photography

Fish N’ Chips

If you're shooting Street Photography at night, depending on the amount of ambient light, you will want to use an ISO value of approximately 1600 - 6400.

This correlates to your Shutter Speed which will need to be fairly fast - 1/60 sec to 1/250 sec. Plus a wide Aperture is also beneficial, especially in low-light conditions.

Within these parameters there are variables, how fast are the people moving? How bright are the surrounding street lights? Are you shooting Urban landscapes?

Let's get into it...

ISO and the Other Exposure Elements

To get a decent exposure at night, you will need to make sure that the camera is letting in enough light. Especially if you are shooting handheld.

This means that, in order to capture sharp images, and not have blurry people in your photos, then you are going to need a fastish Shutter Speed. The number of night lights will denote how fast your Shutter Speed will need to be, as will whether your subject is standing still, and/or how fast the subject is moving. I find that usually, a Shutter Speed from 1/60 sec to 1/250 sec works for me. I'll change the settings to 1/60 when I enter darker areas. Those variables cover all my street photography needs.

Also, with night street photography, in order to work in low light situations, you are going to want to shoot with a wide Aperture. An f-stop from approximately f /5 - f /1.8 will work, in order to let enough light through the lens.

Your ISO will need to be in a range from approximately 1600 - 6400 to get a decent exposure in low-light conditions. That is usually enough light sensitivity to use a faster Shutter Speed, but also not too high that you will get horrendous noise in your images.

Tripod ISO 200 f / 8.0 1.6sec

Auto ISO

Modern cameras today have a fantastic setting - Auto ISO. This feature can be used in Aperture Priority, Shutter Priority and in Manual Mode.

In Aperture Priority, Auto ISO allows you to choose a minimum Shutter Speed, a desired f-stop, and also a maximum (and minimum) ISO, (although not all cameras allow a lower ISO limit). This mode is great for night street photography

For example, if I am using Auto ISO in Aperture Priority, I will choose the desired Aperture, a minimum Shutter Speed of 1/60sec, and select the ISO range from minimum 1600 to maximum 6400. This way I know I will be getting sharp images in low-light conditions because I have a minimum Shutter Speed of 1/60sec and the ISO will only increase, once the Shutter Speed drops to 1/60sec. The ISO will increase up to the limit of 6400 and because I also have a minimum ISO of 1600, won't get so low that the image is underexposed. I can be safe in the knowledge that if I move into a brighter area, the Shutter Speed can automatically go faster to get a correct exposure, but in most cases, it will not go below 1/60 sec.

I also have to take into account the Shutter Speed, focal length rule when programming my minimum Shutter Speed: The general rule of thumb is that when you are shooting handheld on a 50mm lens, don't pick a Shutter Speed slower than 1/50 sec. However, with functions such as Image stabilisation, and knowing your raw strength holding a camera still, there is certainly some leeway with this rule.

One caveat to be aware of. If I enter an area that is so dark that ISO 6400 is just not enough, the camera will override my minimum Shutter Speed and choose to go below the 1/60 sec in order to get proper exposure. Contrarily, I can overexpose the shot as well -if am at the widest aperture of f /1.8, that my lens can go, and I have the lowest ISO (100) and the fastest Shutter Speed is just not enough (1/4000sec), then the image will be overexposed. Then my only option would be to choose a narrower f-stop.

A real-world example of Auto ISO in action - Imagine that I am on a dimly lit street at night and I want to photograph moving people coming out of bars and shops. I use AUTO ISO in Aperture Priority Mode. I choose an aperture of f /2.8. I know that I can hold a camera steady with a 55mm lens at 1/60 sec, so I pick that Shutter Speed. I set my ISO upper limit to 6400 and my lower limit to 1600. If it gets darker or I move to a darker area, I don't have to do a thing. The camera will increase the ISO to the correct exposure once the Shutter Speed at 1/60 sec. If I move into a brighter, busier area, the Shutter Speed will increase automatically along with the ISO to expose the composition properly.

Tripod ISO 1000 f / 5.6 1/4sec

ISO for Urban Night Photography

Urban Photography is a different beast. It's quite simple though, you are not shooting people, you are photographing buildings.

Depending on your camera holding abilities and the amount of light that surrounds the buildings, you can potentially shoot with an ISO of around 800 - 3200, if you can confidently hold the camera steady at 1/60 sec, (with or without stabilization) and also use an Aperture of approximately f/5.

In a previous post, I have mentioned that I always shoot with a tripod when I am shooting Urban landscapes at night. Therefore, I can afford to shoot at ISO 100, with a long Shutter Speed of up to 30 seconds, (depending on the light levels) and with an aperture of f /8 or wider. If I am shooting objects then I can usually take as much time as I would like unless I know that the area is busy, then I will speed up the Shutter Speed and increase the ISO.

Tripod ISO 100 f / 8 1/3sec

ISO For Street Photography

If you know your camera's limits then you know at what level your ISO becomes too noisy for an acceptable image.

With night street photography, if there is a lot of ambient light then you can be flexible with your ISO. You can either try Auto ISO or manually control your ISO. Try anything from 1600 up to 6400, (when or if it gets darker) and adjust your Shutter Speed from 1/250 sec, down to 1/60 sec, (when it gets darker). Also, use a wide Aperture: f /5 - f /1.8, depending on your lenses capabilities.

Tripod ISO 100 f /5 0.5sec

Don't forget! It is much easier to steadily hold wide lenses, 50MM, 35mm and wider, as you will need a faster Shutter Speed when holding longer focal length lenses.

In 2021, cameras have come a long way. There are now technical capabilities that allow night street photographers to take great quality night street photos without any image degradation. Currently, you can use high ISOs without too many noise penalties and I can imagine that this will only improve in the future.

Go forth and create.