Shoot indoors or in low light

The same type of question often comes up in the dozens of emails I receive every day: the management of indoor photography situations (in low light what). Many of you encounter this common problem in photography - running out of light to get a well-exposed, bright enough picture.

If you've already mastered the basics of photography (especially the exposure triangle), as well as semi-automatic modes, you should be able to get by in these situations. But as I often have this type of question, it is undoubtedly that it deserves a reformulation.

I will therefore explain to you what tools are at your disposal to manage this, which will allow you to improve your images, but also to know when it will not be possible to take a satisfactory photo (because no, we cannot do of photo in total darkness).

Technical levers for indoor photography

There are not 36 solutions to deal with the problem, there are 3 of them, which are bound to remind you of something. If you've never heard of this before, then you need to go read my articles on the subject before, as I just give a quick reminder below:

The exhibition

The opening

Shutter speed

ISO sensitivity

The opening

The first solution if you lack light indoors, it will be to increase the aperture used by your device. Remember that the smaller the number, the larger the opening. This lever will come up against 2 constraints, one technical, and the other artistic.

First of all, the maximum aperture you can use is limited by the maximum aperture of your lens. On compacts or bridges, you can't do much about it, but on SLRs and hybrids, as you can change the lens, you can influence that: choose your lens with the largest aperture.

If you don't have one that opens at least at f / 2.8, that's not necessarily going to help you much. So if you're often stuck with a lack of light, you might consider purchasing a larger aperture lens, like a 17-50mm f / 2.8 type zoom, or even a 50mm f / 1.8.

Then, increasing the aperture will have the direct consequence of reducing the depth of field, that is to say the area of ​​sharpness in your image. In other words, to increase what is called background blur, or bokeh.

This can be a desired effect (if you want to isolate the subject from the background in particular), but if you want to have a great depth of field (the image sharp throughout its depth), I advise you to first try to play on the other 2 factors.

But that's why many images taken in low light have a shallow depth of field: you have to compensate for this lack of light.

Let's move on to the second solution.

Shutter speed

You can slow down the shutter speed (or exposure time) you are using, which will allow more light in. Here, the shutter speed is not limited by the camera (you can usually go up to 30 seconds or more in Bulb mode). But here too, this lever comes up against 2 constraints, one technical, and the other artistic.

First of all, you are not going to be able to slow down the shutter speed indefinitely without affecting your image. You must have noticed it before (even if the most beginners among you have not yet understood why), at speeds that are too slow, the image is blurry.

It's a phenomenon called camera shake : Contrary to what you might think, even if you don't smoke and drink coffee, you're not absolutely still when you're holding your camera. At fast speeds this movement remains imperceptible, but at slower speeds it shows in the photo and causes a very unattractive effect.

A well-known and simple rule to remember is that the speed should not be slower than 1 / focal length, if you are shooting handheld. So if you're shooting at 50mm, you should at least use a speed of 1/50 (or faster, like 1/100).

That said, you have to multiply this focal length by a certain number depending on the size of the sensor. For micro 4/3 hybrids, multiply by 2, and for cameras with APS-C sensors (most SLRs, Sony and Fuji hybrids), multiply by about 1.5.

So with the same focal length (written on the lens), you will have to choose at least 1 / 80th on APS-C, and 1 / 100th on micro 4/3, to make it very simple.

You can also place your camera on a tripod, and there you will no longer have a speed limit.

The artistic constraint is also linked to the movement, but not to yours, to that of the subject. Indeed, if it moves, it could be blurred on the image if you use too slow a speed. Quite intuitively, this is all the more true as:

the shutter speed is slow (with equal subject movement)

subject movement is fast (at the same shutter speed)

So if you want to freeze the subject's movement, you won't be able to slow down too much, and you won't be able to play on this lever. Conversely, if you do not have a moving subject, or if you want to blur it, you will be able to use a tripod and rely on this lever only (even using a low ISO sensitivity and a small aperture).

ISO sensitivity

Finally, you will be able to use this last lever, which I call the “safety valve”. Indeed, it is the lever to use as a last resort, when you have already used the aperture to its maximum (considering the technical limit of your lens but also your possible desire to keep a great depth of field), and also the shutter speed (considering the minimum speed to avoid camera shake, the use or not of a tripod, and your desire to freeze the subject).

The downside to ISO sensitivity is that when you increase it, it will create noise in the image. Rather low ISO sensitivities (up to 400 or even 800 ISO) often have very reasonable noise, but beyond that, things generally start to take a turn for the worse.

You should know that it depends a lot on your device : some cameras produce a lot of noise from ISO 1600 (or even less), and for others you have to wait ISO 6400 or more to be bothered. There is no hard and fast rule here: it's up to you to test and see what noise is acceptable.

Warning: evaluate it at viewing size of the photo (in full screen for example), and not by zooming to 100%, which does not make sense.

Adjustment of post-processing exposure

There's also the option of increasing post-processing exposure, especially if you're working in RAW, which is a lot more flexible in this regard. Note that this will produce noise (grain in the photo), similar to increasing the ISO sensitivity. So you won't do miracles if you were already at the maximum acceptable ISO sensitivity allowed by your sensor.

That said, good RAW software generally allows excellent noise reduction (I am thinking in particular of Lightroom, which still amazes me on this point), and will give you a little more latitude.

The other levers

These purely technical levers are great, but there are also other ways to tweak things a bit in shooting that have nothing to do with settings.

Understanding the light

The first is to understand how light works. I had already written an article on light in photography, where I “gave voice to light”. I strongly advise you to (re) read it, because there is no point in repeating it here.

But I can take a simple example: if you are photographing someone indoors in artificial light, a simple method might be to bring a light source closer to the subject (or to bring the subject closer to the source). It can really vary the amount of light enormously, and therefore make the difference between a failed (or impossible to take!) Photo and a successful photo.

Add light with a flash

Obviously, you can also decide to add light in the image, with artificial lighting, usually a flash. The flash included on your camera is very bad : low power, producing too harsh a light and hitting full face on your subject, it will always give an unattractive result, even downright disgusting, let's say it. If you only have that, there are still almost free ways to improve the light.

Otherwise, the best solution is probably the cobra flash. If you think of diffusing it or of reflecting it in one way or another (by directing it towards the ceiling, with a white card,…), the result should be satisfactory after a few tries. Do not hesitate to use it automatically at the beginning.

To learn more, you can read the article on choosing a flash and the one on its use.

How to photograph in low light, concretely?

You're going to tell me that it's all well and good, that you understand how it works theoretically, but that you have a hard time seeing how to put it into practice. I understand you, I had a hard time getting started actually. But you'll see, it's not that complicated.

In aperture priority mode (A or Av)

If you are in aperture priority mode, logically, you want to control the depth of field. In this case, start by choosing the aperture you want, relative to your photographic intention. By pressing the shutter button halfway, the camera will display the speed it will use, in the viewfinder or on the screen.

If shutter speed is important to you (because you're shooting handheld, and / or the subject is moving), watch it. If it is too slow, increase the ISO sensitivity until it is fast enough.

If that is not enough, you can decide to increase the aperture, even if it means losing depth of field. It will change your image, but allow you to have the correct exposure.

If you are at the maximum everywhere, then you come up against the limits of your equipment, and sorry, but you will have to iron!

Note that you can opt for a speed a little too slow, if your only concern is the blur of the camera (and not of the subject): at the limit speeds, with a little luck and you stalling well you can perhaps get a photo sharp, especially if you have stabilization.

If shutter speed isn't important (because you're shooting on a tripod, and the subject is still, or you don't care if it's out of focus), then you're free to shoot.

In speed priority mode (S or Tv)

Here, logically, speed is important to you. If you have trouble in low light, it's probably because it's fast, so you want to freeze the subject. In this case, start by choosing the speed sufficient to freeze the subject (there is no absolute rule, it is necessary to test).

By pressing the shutter button halfway, the camera will display the aperture it will use. If it flashes (or is displayed in red, depending on the device), it means that your device will use the maximum aperture, but that it is still not sufficient, and therefore that the final photo will be underexposed.

In this case, you can increase the ISOs until the blinking stops : the photo will be well exposed. You can also increase the ISO if you want the camera to close the diaphragm a little more (typically to gain depth of field).

If, despite everything, you cannot get the correct exposure, you are reaching the limits of your equipment.

2 different textbook cases (and different solutions)

I'm sure that despite all these explanations, one or two concrete cases could still help you to fully understand all the implications. So let's see this in real life.

The landscape posed cushy

You are at the beach on a spring evening, a little after sunset. The sky is pretty, you have a beautiful setting, in short, you want to take a photo. Only here it is already a little dark. But luck (well foresight), you have your tripod in your pocket or your Mary Poppins bag!

Suddenly, you can put your camera on a tripod, select an aperture sufficient to have the whole landscape in focus (say f / 11). As you are going to be able to play on the lever from slow shutter speed to maximum, you can leave it at ISO 100. The device will decide on a certain speed, but it doesn't matter, you are on a tripod. All that remains is to trigger! (with mirror lockup, and a remote control or self-timer, as a reminder)