When I was in my initial days of photography I was always intrigued by those landscape images with silky smooth water, streaks of cloud in the sky and milky waterfalls. And I always wondered how it is done. Then someone told me that it can easily be achieved by extending exposure time. Now he did not tell me how to go about doing that. Consider this; a rank novice, having purchased his first ever DSLR, with absolutely zero understanding of the concept of Aperture, Shutter Speed and ISO let alone exposure and its concept using Stops etc. being provided only one part of the information. Enthusiastic to try and achieve result, I drive to the nearest river, put my DSLR of a cheap gadget, which was a freebie and a fragile assembly of something that resembled a tripod. Tried extending exposure with whatever best I could understand and the result was a blank pure white frame. More than being disappointed I was embarrassed. This is what half baked information does to you. It did not take me long to figure out what was the missing part of the information. And let me take this blog to share what does it take to create long exposures and create those dream sequences.
So what is Long Exposure? When I Google this question this is what I get as an answer: Long–exposure, time–exposure, or slow-shutter photography involves using a long–duration shutter speed to sharply capture the stationary elements of images while blurring, smearing, or obscuring the moving elements.
Over a period of time, I have managed to create my own definition: Any exposure that is longer than 0.5 sec and ranges between 0.5 sec to 30 sec when shot using Manual Mode and from 30 seconds to infinity (whatever time I decide to keep the shutter open for) when using BULB mode, is called Long Exposure.
How do we achieve it?
Long exposure can easily be divided into two categories:
- Milky Way and/or Star Trail Photography
- Daytime Long Exposure Landscape Photography
We are not discussing the first part here today. Lets see how to achieve long exposure during daytime to create dreamlike landscape images. Basically we need “something” to cut down the amount of available light. And that “something” is Neutral Density Filters (ND Filters). A Neutral Density Filter is simply a high quality piece of glass that reduces the amount of light reaching camera sensor. “Neutral” means that it should not shift the colors while cutting down the light.
Here are a few must haves to get best possible results:
- A good and sturdy tripod
- Set of ND filters
- Set of Graduated ND filters
- Circular Polariser
- Remote Shutter Release
What Filter to use?
It depends on what kind of effect you want to achieve. For example if you are shooting the turbulent sea and you want to shoot crashing waves in such a way to keep it between the complete freeze to complete silky smooth, then a 3 stop or a 6 Stop filter will be the choice but if you want to create a silky smooth look, then you may need a 10 or a 15 stop Filter.
Finding out which filter will be appropriate comes with experience. Remember, you can achieve varied results using different filters at the same spot using same composition.
Set up the Camera and Important Tips
Long Exposure landscape photography can get frustrating for beginners but as in any other situation, here also practice makes you perfect. Setting up the camera the right way will help you achieve better results faster and keep frustration away.
- Composition is the key. Don’t neglect this important aspect. Just reaching an exotic place to shoot is not enough; you must find your unique composition before you start setting up your camera. Take your time on this step.
- Put the camera on a sturdy tripod, which is set up on firm ground. Tripod is or should I say a good tripod is must have for long exposure photography. Remember your shutter may remain open for a few minutes and the camera has to be rock steady all this while. Your tripod should be able to withstand and absorb the vibrations caused by strong winds, crashing waves or at time both at one time. Don’t settle for cheap.
- Shoot in RAW format
- As far as possible use lowest possible ISO to get minimal high ISO noise. As such your image will show some long exposure noise.
- Close down the aperture to around f/8 or f/11. Remember smallest aperture does not always give you sharpest images. When light passes through small apertures (f/16 or smaller), it starts diffracting (dispersing) resulting in less sharp images.
- Turn off your Image Stabiliser. Image stabilization is for handheld shooting. Your camera is already on a tripod and IS may try to auto correct smallest of movement and may ruin your final image.
- Lock the mirror. Best images are created when you take care of smallest details like Mirror Lock. This will remove the possibility of vibration created by the mirror movement while pressing the shutter button.
- Use Remote Release Cable. This will help you keep your hands off the camera. This is a must have when you are shooting in Bulb mode.
- Shoot in Bulb mode Usually people use this mode when they want to use shutter speeds longer than 30 secs but I prefer using is every single time I am shooting long exposure. Even when I have done my calculation of the correct exposure time, I am constantly thinking about the final image and using Bulb mode helps me stay flexible with the exposure time.
- Calculate Base Exposure. Set the right aperture at lowest possible ISO and get the exposure reading. This will help you calculate correct exposure time based on the type of ND filter you are using.
- Lock the Focus. Some ND filters can be very dense making it impossible for the ambient light to pass through to let the camera focus. Therefore its best to compose and focus. Shift to manual focus and carefully put the filter. Since I use Square Filter System, there is always a possibility of accidentally shifting the focus. For this I use Gaffers Tape. This has strong adhesive property and does not leave a residue once removed.
- Fix the ND filter. As mentioned above carefully fix the ND filter set on the lens. I first put the desired ND filter and/or GND filter in place before putting on the filter holder unit on the lens. This ensures I do not fix the filter in wrong slot and do not accidentally break the filter.
- Cover the Viewfinder. This is to prevent stray light sneaking in and affect the exposure.
- Calculate the right exposure time based on the density of ND filter being used. For example if you are using a 10 Stop Filter your correct exposure can be as under:
Exposure details on the Test Shot (without filter): f/8, 1/100, ISO 100
Now in Bulb mode fix the Aperture and ISO as per test shoot and change the Shutter Speed for 10 Stop Filter. The final calculation will be: f/8, 16 secs, ISO 100
You can use available apps for your Android based phone or iPhone to calculate exact correct exposure.
- Now start shooting. Take care to keep the camera and tripod as stable as possible. If there is strong wind stand in a way to block the wind from hitting the tripod.
- Check histogram. Don’t forget to check the histogram after the shot is taken.
Long exposure photography requires more planning and post processing than other forms of photography buts all worth the effort. Long exposure photography using ND filters can be addictive in nature. So what are you waiting for. Pack your filters in your camera bag and set out to shoot stunning dreamy landscapes using long exposure.
Here are a few of long exposure images using ND filters: