Long Exposures (Slow shutter speed.)
- Use long exposures when shooting in the dark. The slow shutter speed will let in more light
- Long exposures are often used to photograph water to get a milky effect
- Use to get trails of light; e.g. car lights
- Zoom burst – as the photo is being taken, change the zoom
- Focus burst – manually change the focus as the photo is being taken
Using the BULB setting
The slowest shutter speed setting on the camera is 30 seconds. If you set your camera to manual, you will also have the BULB setting.
When using the BULB setting, you can control how long the exposure is with your finger. You are taking control of the shutter speed. If you press the button for 1 second, this is the equivalent of having a shutter speed of 1 second.
You might want to have a 15 minute exposure. Keeping your finger on the shutter for 15 minutes isn’t practical so for this, you need a shutter release remote control. You can lock it to get the desired exposure time
Getting the correct exposure
If your photo is too over exposed, increase the aperture (e.g. f29)
The lowest ISO gives you the slowest shutter speed
Variable ND (Neutral Density) filters
Using an ND filter is essential when taking long exposures in the daylight. It’s advised that you buy a 77mm filter as this will cover all sizes of lenses that you have. You should also buy step up rings which attach to the filter and allow you to use it with other lenses.
If yout exposure is long enough, you can actually get rid of people / moving objects from your photos. If people are moving, they will not be recorded on the picture.
Avoiding camera shake
When using long exposures, you are in danger of camera shake which will blur your photos. In order to avoid camera shake with slower shutter speeds, try one of the following
- Use the self-timer feature. This avoids camera shake when you press the shutter
- Use a remote control – either a wireless one that connects via Infrared or one that plugs into the camera
- Use your smart phone as a remote control. If your camera supports WiFi, you can take the photo with your phone.
I have the Play Memories app on my phone which controls my camera when the WiFi option is selected in the camera wifi menu.
This week’s task was to take photos using long exposures. In order to do this, I purchased a variable ND filter, step up rings and a mini tripod.
Exercise 1: Taking a photo of myself in several positions
I took the following photo using the slowest shutter speed I can get on my camera – 30 seconds. In the photo on the right, I sat in three different positions and switched the light off with a remote control each time I moved. On the photo you can just about see me very faintly. I think that I would need a longer exposure to see me more clearly in each position but I don’t yet have a working remote control.
Exercise 2: Writing with light
I first experimented by writing the name of my name and my cat’s name with a torch!
I then went out into my garden when it was dark and tried to create the outline of a bottle using a flashlight. I then realised that I could actually draw a glass in light, though my drawing skills leave a lot to be desired! I was wearing black but unfortunately you can see my hands so next time I would wear black gloves. My final exercise in light drawing was to attempt a picture of a cat!
Exercise 3: Light trails
I went to a bridge over the A316 with my mini tripod to try and get light trails from cars.
I had to be careful on three counts:
- There were people walking over the bridge so I had to ensure that I, and my equipment, was not in their path.
- I checked several times that my tripod was firmly attached to the rails so that it didn’t fall onto the road below and cause an accident.
- For my own safety, I didn’t want to stay on the bridge for too long, alone and with expensive equipment
My first attempt was over exposed and I realised that my ISO was set to automatic and I hadn’t increased my aperture. I then set the ISO to 50 and increased the aperture to the highest possible, f29. This was the result. Not the prettiest of photos but a successful first exercise.
Exercise 4: Long exposure of water
I used my new ND filter and mini tripod to take the following photos. I tried different exposures to see how the effect varied. As the shutter speed increased, I found that I had to use a wider aperture and/or change the filter as the photo became too dark.
- I tried to focus on the water in some shots but in hindsight I should have focused on the bank at the end of the lake and some of the photos are blurry. I used auto focus but would perhaps have been better off using manual focus. It’s also possible that there was some camera shake even though my camera was on a tripod as it was quite windy
- I’ve also noticed that you can see black marks at the corners of the photos. I’ve learned that this is probably due to the fact that I bought and used several step up rings rather than just one that fits my lens. I will now look to purchase a 62 – 77mm step up ring that will fit my 62mm lens and 77mm filter
- My sensor may need to be cleaned. I need to also check for dust on the lens beforeI take any further photos. Sensor dust can be eliminated in Photoshop using the spot tool.
Comparing the shortest exposure with the longest:
Left photo: 1/500 secs ISO 125 f4
Right photo: 30″ secs ISO 50 f22
Exercise 5: Moving the camera
This is what happened when I focused on lights at my window and moved the camera
Exposure time: between 4 – 6 seconds – f18
Exercise 6: Zoom burst
I also tried a zoom burst focusing on my cats but it didn’t really work. They were taken handheld and the subjects were probably not totally still.
Exposure time: 6 seconds – f18
Criteria covered in this blog:
Unit 01: 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 2.10