Choosing the right manual camera settings for the image you want should be straightforward, but there is so much conflicting and / or overly technical information out there, that I really struggled to make the jump from ‘point and press’ to knowing what to set to get the images I wanted.
This is Part II of the four part epic saga, The Path of the Photographer.
This post is aiming to help make the step from the fully automatic ‘let the camera choose’ to the ‘this is what I want to capture’, and provides a deeper explanation of how I got to the ‘set and forget’ settings I outline in my previous post. It is also meant to be camera / gear agnostic.
Contents
The Holy Trinity of Light
An image is captured on the camera sensor by the opening of the aperture blades in the lens when the shutter button is pressed. The shutter noise you hear is either the actual blades in the lens opening and closing, or your camera playing a noise that sounds like that. It is one of my favourite noises, and I love it. It tells me that magic is happening.
Very simply, the image is created by balancing the holy trinity of light: Aperture, Shutter Speed and ISO:
Aperture : Is how much light the camera lets in, based on how wide the blades in the lens open. The wider the blades open, the more light comes in.
Shutter Speed : Is how long the aperture is open for. The faster the shutter speed, the less time the blades are open, and the less light that comes in.
ISO : Is how sensitive the sensor is to light. Adjusting the ISO value adjusts the sensitivity of the sensor.
Using the fully automated capability of your camera puts the control of the balance of these three into the hands of your camera. Using the camera’s presets will select different combinations of aperture, shutter speed and ISO to match the scene. For example:
Night Scene; will have a low aperture value (wide opening, more light), a slow(ish) shutter speed (more light), and a high ISO to increase the sensitivity of the sensor.
Landscape; will have a high aperture (narrow opening, less light, but more of the image in focus), a low ISO, assuming good light, and a shutter speed that matches light conditions. Mountain is this plus an adjustment for the extra light being reflected from snow.
Sport; will have a fast shutter speed (to freeze movement), and the camera will balance ISO and aperture to the light conditions.
These scene presets give competent results, but can be average / soulless. If you want to capture the mood, atmosphere or feeling, understanding the holy trinity of light is key.
Here is the impact of each.
Aperture
Your lens contains blades which open to a defined position called an f-stop. Somewhat counterintuitively, the lower the f/# the wider the lens blades are opening and the more light is being let in.
So why not just set the aperture to get the most light into the camera?
Good question. The width of the aperture opening defines the depth of field², i.e. how much of the image is in focus.
It defines the distance in front and behind your focal point that is sharp.
A wide aperture, like f/1.4 has a very narrow depth of field, literally only a couple of centimetres (less than an inch). So only what you focus on is sharp, and the area in front and behind will be out of focus. This can result in the much hyped and desired bokeh³, where the foreground / background becomes aesthetically blurred. Bokeh tends to only appear below f/2.8, and some lenses do not go that low; telephoto lenses, for example, may start at f/4.
The blur of the orchids behind the focal point is also bokeh
As the f-stop increases and the aperture narrows, the depth of field increases and more of the image is sharp.
So traditionally landscape photography will be f/5.6 to f/22 to get the whole image sharp, with lower apertures used in portraiture or detailed images to isolate your subject. A low f-stop can be great for portraiture, where you can achieve the effect of having your subject’s eyes in focus, but their nose tip and ears lightly blurred drawing the viewer’s eyes to the eyes of the subject.
In the above two images, I took the first one on my favourite landscape setting, f/22, but the light was failing and the shutter speed was too slow to make it feasible to hold the camera, and I worried about camera shake in the resulting image, so I switched to f/3.5 to let more light in. Even though the f/3.5 has a very shallow / narrow depth of field, it is hard to see the difference between the two images.
Shutter Speed
Shutter speed is how long the aperture remains open at the defined f-stop. As you would imagine, the longer the aperture is open (slow shutter speed), the more light is let in, and the faster the aperture closes (fast shutter speed), the less light is let in.
So why care about shutter speed? Movement. If anything in your image is moving, a shutter speed that is slower than the movement will result in movement blur. This might be what you want, but if it isn’t, then the shutter speed needs to be fast enough to freeze the movement.
See the movement blur of the wings of the landing Puffin
Generally speaking, 1/500 seconds (i.e the aperture is open for 0.002 seconds) is fast enough to freeze stationary or ambulatory bird movement, and 1/1000s (i.e. open for 0.001 seconds) is fast enough to freeze most animal movement and birds in flight.
Another reason to care about shutter speed is whether you can hold the camera still for the time the aperture is open. Most lenses have an image stabilisation system, which will extend the range of shutter speeds the camera can be held at without camera shake / blur (your ability to keep the camera steady for the time the shutter is open), but in reality, the limit is around 1/50s and shutter speeds slower than that will need a tripod or other stable platform for the camera to be still enough.
Photographing water (waterfalls, waves etc.), presents a choice, either a super sharp image (splashes, wave crests), or a cottony, dreamy blur. The choice is yours.
In these images, I wanted the wave frozen as it broke on the rocks, so chose a 1/2000s shutter speed to freeze the movement. For the waterfall, I wanted the dreamy blur, but I didn’t have a tripod or somewhere to rest the camera, so I squeezed the shutter speed to 1/8 seconds to get some blur without introducing camera shake, though a longer shutter speed would have been preferable.
Balancing Shutter Speed and Aperture
Before I talk about ISO, it is worth taking a look at aperture and shutter speed together. In good light, ISO is a set and forget (and I recommend ISO 100), so I am really only making a decision about aperture and shutter speed.
Most / all cameras have a setting called Aperture Priority and one called Shutter Priority. All these do is put the aperture or the shutter speed in my hands, and the camera sets the other based on light conditions.
I think about the light I need for an image as a full glass of water. I am using the tap (aperture) and how long the tap is open (shutter speed) to fill the glass.
Using Aperture Priority is setting how hard the tap goes on. The camera will determine how long the tap needs to be open (the shutter speed) to fill the glass.
Using Shutter Priority is setting how long the tap will be open. The camera will determine how hard the tap needs to go on to fill the glass.
I will use Aperture Priority where I am taking a photograph of something that is not moving and where I want to control depth of field. I will choose my f-stop (aperture opening), based on how much of the image I want to be sharp / in focus, and whether I have a subject (flower, person) that I want to highlight.
In the above two images, the difference is the aperture setting I chose. For the f/1.4, the shutter speed is 16,000th of a second, and it mutes the colours, but the iceberg in the front is the focus of the image and the background is blurred. In the f/22 the colours are brought out more, because of the longer shutter speed and the increased depth of field, and the icebergs / waves in the background are sharper.
I will always choose to be at the upper or lower end of the f-stop range of the lens I am using as I think I get cleaner / crisper images. So on my 50mm lens, I use f/1.4 to f/3.5 and f/16 to f/22 only. And I find these do everything I need.
I will use Shutter Priority where I want to capture movement, either by freezing it, or by blurring it. I will choose the shutter speed based on the movement type / speed and the effect I want.
As noted above, 1/500s to 1/2000s is fast enough to freeze most movement. And 1/5s is slow enough to blur movement, especially water movement. Though you can go slower to get more blur.
Challenges of Using Priority Modes: The camera will assess the amount of light based on the aperture or shutter speed selection, based on how it is metering the exposure of the image. There are a couple of things to consider about this.
There isn’t enough light for 1/500s and the aperture limit on the lens (f/4.5) to give the right exposure
Pushing the limits of the light. For example, using f/1.4 on a really bright day means the shutter speed has to be incredibly fast not to overexpose the image. Using 1/2000s on a dull day means the aperture has to be incredibly wide not to result in under exposure (i.e. dark image).
The camera cannot go beyond the physical limits of the lens. So if I am asking for 1/2000s on an overcast day and the lens is f/4 at the widest, the camera will struggle to get enough light in and I’ll get a dark image (and this is where ISO comes in, more on that below).
If I am asking for f/1.4 in bright sunlight, I may get an image that is overexposed. Same if I am asking for a long shutter speed on a bright day (for the fluffy water effect), f/22 may not be a small enough aperture to limit the light to get the right exposure (overfilling the glass).
So I will check the exposure from the histogram or by a preview of the resulting image from a half press on the shutter button. If I am getting a blown image (over exposed, too much light), or an underexposed, dark image, I will think about increasing / decreasing aperture or increasing / decreasing shutter speed, to balance to the result I want.
There is often more light than the camera thinks there is, and / or I am metering across the image as an average. Grass, water, snow, ice, all reflect light that the camera doesn’t necessarily catch when it is metering. Or the camera is going for what your eyes see, which may be too bright.
In these images, letting the camera choose the exposure (shutter speed) results in the flowers getting blown out (overexposed, too much light). Whilst this is the image closest to what the eye sees (without sunglasses), some of the detail (and beauty) is lost.
By stopping down, the image becomes darker, but the detail on the white of the flower comes in and the flowers have depth.
Stopping down is reducing the amount of light by either reducing the aperture / f-stop or increasing the shutter speed. Stops are a whole other subject, written about by others more capably than I can, so here is a link to wikipedia to explore more.
ISO
So where does ISO⁴ fit? ISO is how sensitive the camera sensor is to light. An ISO of 100 is a pretty normal setting where there is enough light for me not to have to worry about it when selecting Shutter Speed or Aperture. I will set it manually to ISO 100 and leave it alone. Some cameras start at ISO 100, others lower (my lowest setting is ISO 50), and run to 6,400 and above (mine is 50,000 max).
So why not increase the sensitivity of the sensor to pick up more light? What’s the problem? Noise. Noise is a strange word to use for an image, but it’s very apt. Making the camera sensor more sensitive to light will result in it picking up stray light bouncing around. The higher the ISO the more sensitive and the more stray light is picked up.
This picture was taken on Shutter Priority at 1/2000s in reasonable light, and my lens aperture was at its limit at f/4.
I had put the camera on auto-ISO and as this was my first Puffin experience, I got over excited and wasn’t paying attention.
The camera selected ISO 800 to balance the light based on the fast shutter speed and aperture.
In this image the ISO was 1,000, and the noise / graininess is really obvious. Especially on the background.
The higher the ISO, the more grainy the image, and the more the detail is lost.
This may be fine for very low light where you can’t use a tripod, but I would avoid it if possible.
So to summarise, if the camera cannot get enough light in to fill the glass with water from the aperture and shutter settings, and it has been given permission (auto-ISO) to flex the ISO, then the camera will adjust ISO to top up the glass to full. This may come at the expense of adding noise which reduces detail.
I have found, through trial and error, that the limit for my camera for noise is around ISO 400. If I am trying to take pictures in low light, where I am using a fast shutter speed, I will try and get the shutter speed as slow as it can feasibly go to freeze the movement whilst keeping ISO below 400.
You can check the settings for a specific shot on most cameras by a half press on the shutter button. Most cameras will display the f-stop, shutter speed and ISO and the expected resulting image.
Night Shots
Conversely, I will keep ISO to 100 and aperture on f/22 for night shots. I will use a solid tripod and sit and wait while the camera counts down for the shutter speed it deems necessary for the shot. Even at night, there is more light than you might expect, so I may still stop down, but using these settings and a tripod means you get beautifully crisp images if you are patient.
My camera has two phases for a night shot, one is the shutter speed and the other is an image stabilisation phase. So the shutter may be open for 60 seconds and then this is followed by another 60 seconds for the image stabilisation. if your camera does this as well, learn a lesson from me and don’t move it in the second phase. It does mean for the below shots I was waiting 2 minutes to be able to take another shot / move, but I think it is worth it.
If you have less patience, go for a wider aperture, but keep ISO as low as you can.
So this is how I moved past point and press, and got to the settings I provided in my last blog.
Contact me if anything in here piqued your interest or you would like any more information on anything I have mentioned.
Notes:
- Chiarascuro; use of strong contrasts between light and dark, light and shadow, to create mood. Wikipedia
- Depth of Field; distance between the nearest and farthest objects that are in sharp focus in a photograph. Wikipedia
- Bokeh; Japanese, the aesthetic quality of the blur from out of focus areas of an image, when using a wide aperture. Wikipedia
- ISO; International Organisation for Standardisation; it just means that ISO 100 is the same in every camera brand and type.