What is the Long-Exposure landscape?
Long exposure is the method to remove or reduce details from moving subjects through prolonged shutter speed, from several seconds to several
minutes. Long exposure is not new technique. It has been used many areas, especially in night photo. It turns head light of car into streak of lines on night scenary, or make stars as trails of line on night sky. At busy day time, long exposure can make buildings without showing a car or pedestrian in architechutre photo. In here, we’ll discuss about landscape especially contents water, sea & cloud.
Why Long-Exposure now?
Personally I don’t like following trend, fashion or too much popular way. I prefer to go to the other direction and build my own style.
Long exposure is, I think, the main stream of Black and White landscape nowadays. Almost every photo-community and gallery present
some sort of long exposure photos. It’s so popular te make hesitating to get in there, ‘aleardy-too-crowded’ place.
But learning good technique is different matter. Long exposure delivers its own beauty in the scene, so hard to resist for landscape photographer.
Finally I packed up gear, newly arrived Sony A7m2, and made trials as below.
Like above, long exposure in 30 sec shutter time can not be achievable by aperture ring alone. Here’s tooling we need:
- ND filter – it reduces the amount of light to the lens, like sunglasses to our eyes. Depends on reduction rate, it described like ND4, ND8, ND16….etc. Number represents inverse of multiply 2, so 1 stop reduction is ND2, 2 stop reduction is ND4, and 3 stop reduction is ND8…etc. Typical daylight requires at least 10 stop reduction to reach to 15 sec or more, so I recommend at least ND400.
- Tripod – Heavier the better. Don’t think about small & light one you bring to avoid asking someone for selfie. It is not going to work at all. To resist vibration in windy day, prepare heavy and sturdy tripod.
- Lens hood – It is not mandatory, but essential to prevent bad influence from direct lighting to filter. Expecially long-exposure is prone to image degradation if filter glass exposed to direct lighting.
Key points and/or worth to note
- Focus adjustment – reducing 10 stops of light means DSLR view finder become useless, no mention AF function for them. But with mirrorless camera if it supported high ISO, we can use view finder without big problem. In DSLR, user has to make focus without Nd filter first, set the lens to manual mode, then install ND filter for shooting. I will explain the set-up of Sony A7m2 at below in this article.
- Virbration – favorite scene of long exposure such as high waves and fast moving clouds along seaside is ‘strong windy day’ without exception. Therefore long exposure is bascially fighting with the wind to hold the camera securely upto several minutes. Even with heavy and sturdy tripod, it will vibrate in strong wind definitely. Strap of camera and tripod makes situation worse because of easy shaking in wind, so better to take them off or hold them during exposure to avoid vibration transmitted to the body. Adding camera bag on the tripod to add weight is not working either. It will catch the wind and start to swing like sail (typical example of theory vs actual).
- When search the point of shooting, need to consider the wind carefully. For example instead of staying on top of breakwater where open to wind, move 1 or 2 step down to place the tripod where breakwater set behind and protect from direct wind hitting.
- Exposure longer than 30sec – Most of digital cameras support 30 sec auto-exposure as maximum and then move to ‘bulb’ shutter. Bulb shutter is manual operation. It open the shutter while finger presses shutter release button and close shutter when finger removed. Longer than 30 sec exposure, I don’t recommend your finger for operation because hard to avoid vibration induced by human body.
- Multiple alternatives possible depends on camera platform, but most likely ‘cable release’ or ‘remote control’ is the best solution.
How to set up Sony A7m2 for long exposure?
Surprisingly, recent mirrorless camera can catch very dim light which reduced by 10+ stop ND filters and show decent enough display through the finder.
It’s unimaginable in old days (not so long ago) doing long exposure while focusing through the finder.
- Focus setting : MF (manual focus)
- Effect of adjustment : Disabled
- Steady shot: Disabled
- ISO: 50
When AF lens set to MF in focus mode, turning focus ring in any direction slightly will kick off ‘manual focus assistant’ function & enlarge the scene 5.9X times. You can easily see focal point and make precise adjustment. If manual lens used, simply click ‘manual focus assistant’ button to enable 5.9X enlargement.
The reason disabling ‘Effect of adjustment’ is the finder stay bright even in case aperture close down to f11 or f16. If not, finder will become dimmer when aperture close down which is exactly the effect of adjustment.
Steadyshot while using tripod often malfuctioned, actually it over-react. So better to disable it.
Don’t forget to set ISO to lowest point if auto-ISO used.
Below is typical landscape what we see in our naked eye.
It describes the scene strictly, coming waves, clouds, slanted sunlight in the afternoon.
Long exposure in the same scean shows much different mood.
In real world, we never see the cloud as light streak, or sea as mirror like calm & smooth surface.
So uniqueness of long exposure is it is ‘NOT real world’ but looks like very real scene