How to get clean night shots with any equipment
Introduction
We all know the main problem of low light photography: photos often turn out too noisy. Yet, more often than not, the actual reason why the photos are bad is not the noise itself but inefficient settings with the noise only being the consequence rather than the cause of bad photos. In this blog, I want to share some ideas on how to get cleaner photos in low light no matter the gear you use.
Gear
On that note, having reasonably bright lenses matters for low light photography but do not think that you absolutely need f/1.4 primes or a full frame sensor to take good photos in low light. First, your sensor performs only as well as your lens allows it to meaning that a full frame sensor will not drag you out of the shit if you shoot in less than ideal light at f/4 because your lens does not open further. Second, even if you have a good lens and camera, it still takes a lot of practice to get most out of it in fable light. So let’s get to the actually important aspects in the following sections.
An f/2 lens on an APS-C camera is good enough.
Shoot wide open
This one might sound obvious to those who have been doing night photography since a while. Low light by definition means that there is little light available in your scene, meaning that you will want to maximise the light gathering capabilities of your camera which works best by shooting wide open. In other words, open your aperture to the smallest f-number your lens allows. For prime lenses that often is f/2 or even f/1.4 while for zooms, it might be f/4 or f/2.8. If you photograph on a kit zoom, the aperture is often variable meaning that your aperture gets darker as you zoom in: in that case, shoot your lens at the widest focal length such as 18mm (on APS-C) or 28mm (on full-frame) because that is where your lens has the smallest and therefore brightest f-value.
Shoot wide open: in this case I shot at f/1.4.
Efficient shutter speed
Now that we’ve maximised the light coming into the lens, let’s talk about how to control the light that hits your sensor: shutter speed. A problem I see in many photos is that people shoot at inefficient shutter speeds, so shutter speeds that are either too slow or too fast. A shutter speed that is too slow means that everything moving will be blurry due to motion blur or the entire photo might be blurry due to camera shake. A shutter speed that is too fast means that the sensor is exposed to light for too briefly, meaning that it will not be able to collect enough light. Accordingly, the camera would have to compensate for the lack of light by increasing the ISO gain to properly expose the scene leading to the unwanted noise in your photo. So in a nutshell:
too slow shutter speeds = blurry photos and
too fast shutter speed = noisy photos
I shot at 1/40 s to collect as much light as possible as it was VERY dark. The biker is still acceptably sharp.
How do we find an efficient shutter speed that is neither too slow nor to fast? Generally speaking, we use a formula which is 1/(2 x focal length). That shutter speed is enough to keep your frame steady, “freeze” your subject sufficiently and also let in enough light to not raise the ISO excessively. So if we apply this formula to a 35mm lens, for instance, the optimal shutter speed would be 1/(2 x 35mm) = 1/70s.
This photo is taken on a 35mm lens with the formula based shutter speed of 1/70s.
Bear in mind, however, that the shutter speed formula is just a rule of thumb: it will be enough to freeze a walker walking at moderate speeds but if your subject is faster, such as a car or a bike, for instance, you might have to increase the shutter speed to 1/125s or even 1/200s, albeit at the expense of some more noise in my photo. Bear in mind that your subject never has to be 100% crisp as minor amounts of motion blur will not be visible unless you zoom 200% into your photo.
This walker was quite slow. Therefore a shutter speed of 1/60s was enough to freeze his movement.
A very slow shutter speed can also get you some fun effects: here “shutter drag” at 1/15s.
Underexpose
I often hear people complaining about too much noise in their photos. If not due to inefficient apertures or shutter speeds, it is due to you not underexposing your photo. I usually shoot in semi automatic modes where I fix the aperture and shutter speed (as above) while I let the camera take care of ISO. What I noticed, however, is that in semi automatic mode, most cameras tend to use unnecessarily high ISOs making your scene unnecessarily bright, much brighter than it was in reality. To counteract this unwanted level of brightness, you use exposure compensation: it allows you to darken your exposure for it to match what the scene looked like in reality. I usually underexpose by -1 EV but you have to try out a bit for yourself because depending on what camera brand you use, you might have to underexpose a bit more or a bit less. Apart from your exposure looking closer to reality, there is two additional side effects of underexposing:
Your camera uses a lower ISO value meaning that your photo will be less noisy.
You are less likely to blow out the brightest parts in your scene that tend to be irrecoverable especially at high ISOs.
Here I underexposed by -1,5 EV lowering my ISO from 12800 to 4000.
Try to get the composition right in camera
Getting the composition right in camera is often overlooked in combination with low light photography. However, the better you get the composition in the field, the less you have to crop in post-processing. Why does it matter? The more you crop, the more you magnify the high ISO noise in your photo making noise patterns look bigger and your photo overall less clean. This is by the way also the reason why bigger full frame sensors are said to perform better in low light relative to smaller APS-C or four thirds sensors because they are in fact nothing else than a crop of a full frame sensor meaning that you magnify the noise. Brighter lenses for your smaller censored cameras can, however, offset the difference in sensor size allowing you to shoot at lower ISO levels.
Cropping too much can make the noise more visible but in this case it does not hurt.
Option of last resort: Denoise
If you have tried all the things above, it is still possible to end up with a noisy photo. In that case, denoising softwares to the rescue! Softwares like Lightroom or DXO Denoise are able to distinguish between real detail and noise while effectively removing the latter. However, there is still a few things that can go wrong: you might notice that at really high ISO values, the denoise tool might soften the image too much making it look unrealistic and kinda AI generated. In that case, de-noise the photo again but reduce the intensity of the denoise from 100 to 30, for instance. While it means that some noise will be retained in the de-noised file, it also makes the photo look more realistic and organic compared to the maximum intensity denoise. Finally, bear in mind that a bit of noise in your photo does not hurt and can actually be pretty which is why some people even add grain to their photos afterwards.
This photo I could have de-noised but decided not to as the grain adds to the scene.
Thanks for reading! :)
