This article looks at how to:
- either avoid, or purposefully include, blur due to camera shake or movement of the subject, camera or lens
- freeze motion.
Slow Shutter Speeds
For this exercise I used shutter priority mode (something I don’t normally do) which means that I set the shutter speed and chose the ISO, and the camera chose the aperture needed to properly expose the photograph.
The photo below was taken with the following settings:
- Shutter speed: 1/60 second – which has resulted in the fast moving water appearing blurred
- ISO 200
- f9 – leading to quite a large depth of field.
Next, I changed the shutter speed to be four times slower than before. Because the shutter stayed open for longer, the aperture had to become smaller so as to let in less light – otherwise the photo would have been overexposed.
The new settings were:
- Shutter speed: 1/15 second. The water is very blurred and there is a blurry marble on the marble run.
- ISO 200
- f18 The resulting photo has loads of depth of field, due to the small aperture.
To reduce the shutter speed even more, I changed the ISO from 200 to 100.
- Shutter speed: 1/8 second. The water wheel and marble are even more blurred.
- ISO 100 – the lower ISO is less sensitive to light, meaning that the shutter could stay open for a longer period of time without overexposing the photo.
- f16
We’ve seen that as the shutter speed gets slower, motion blur increases and this can be a useful way to show movement. The image below is by Negative Space from Pexels.com. The star burst effect is due to the small aperture.
To show blurred movement in circumstances where there is more light it’s possible to use a neutral density filter to block some of the light coming through the lens. This method is sometimes used by landscape photographers to make moving water appear blurred. I don’t know for sure whether USAGI_POST used a filter to create this photograph of a waterfall, from Pixabay.com. It seems likely that, without a filter, a long shutter speed might have resulted in an overexposed image.
Of course, it’s not just motion in your subjects that is captured with slow shutter speeds. As the shutter speed decreases, you are also more likely to suffer from the effects of camera shake and would be advised to use a tripod to hold your camera steady – particularly at longer focal lengths.
Here’s an example to demonstrate the problem. This is cropped from a photo shot at 90mm, ISO 200, f13, 1/10 sec, without using a tripod. Nothing in this image looks really sharp.
As a general rule, at slower shutter speeds you will want your camera to be held as steady as possible to avoid the risk of camera shake. However, sometimes you might want to move the camera on purpose during the exposure for artistic effect. For example:
- panning – moving so that your focus point remains on a subject that is moving horizontally across the scene. The idea is that the subject is sharp and the background blurs, to show speed.
- zoom bursts – starting with your lens zoomed in to its greatest focal length and zooming out while the shutter remains open.
- moving the camera during the exposure to create an abstract effect.
I took this next photo inside where the level of ambient light was quite low. I moved the camera around while the shutter was open, to produce an abstract pattern.
- Shutter speed: 3.2 seconds
- ISO 100
- f18
Fast Shutter Speeds
So far we have been considering what happens at slow shutter speeds, but you’ll often want to keep your shutter speed reasonably high to avoid camera shake and/or freeze motion.
Right at the start of this exercise, my initial photograph was taken at ISO 200 with a shutter speed of 1/60 second and an aperture of f9. To give me a faster shutter speed for the photo below, I opened up my aperture so that my lens would let in more light. I was also helped here by the fact that the sun came out and, even though I was in the shade, the increase in light levels allowed a faster shutter speed.
My new settings were as follows:
- Shutter speed: 1/800 second. The water no longer looks blurred.
- ISO 200
- f2.8 which is the widest aperture that I could set with the lens that I was using. With this aperture there is less depth of field (the bushes are not in focus).
Next, I increased the ISO to increase the camera’s sensitivity to light, allowing an even faster shutter speed:
- Shutter speed: 1/2500 second. I’ve frozen the motion pretty successfully, as shown in the image below which is a crop of the photo I took with these settings.
- ISO 1600. There is some noise due to the high ISO.
- f2.8
If you want to increase your shutter speed without using a high ISO then you are going to need more light – either by moving into an area with more ambient light or by adding some extra lighting. This could be either constant lights or flash.
I relocated into an area with bright sunlight and tried again:
- Shutter speed: 1/2000 second.
- ISO 200. There is less noise in the photo below than in the previous example.
- f2.8
For an alternative approach, back in the shade, I used my flash to add the extra light I needed.
If you want to freeze motion with flash then it helps not to set the flash to full power as at full power it fires for longer than it does at lower settings, so I set my flash to one quarter power. I switched from shutter priority to manual exposure mode and used my camera’s flash sync speed.
- Shutter speed: 1/160 second (my camera’s sync speed).
- ISO 200.
- f9 I no longer had to use a wide open aperture since the flash gave me all the light I needed.
When using flash, I tend to set my shutter speed to my camera’s sync speed, but you can get interesting effects by combining flash with a slow shutter speed. For the photo below, I used my flash but with a shutter speed of just 1/10 second. This has given me motion blur, but also some areas where the flash has frozen the motion.
Conclusion
If you use your camera with a fully automatic setting then you may find that you end up with blurred photographs, particularly when the light levels are low or your subject is moving.
Personally, I tend to use aperture priority, rather than shutter priority mode. But when I do this, I take account of the shutter speed resulting from my chosen aperture and ISO. For example, I may choose a wide aperture, not necessarily because I want a shallow depth of field, but because I know that it will give me a faster shutter speed. In very low light, I’m likely to use both a wide aperture and a relatively high ISO.
