Did you have any trouble determining the right exposure when using the ND filter for landscape photography? This guide offers a variety of ways to get you started.
Long exposure is a useful method in many styles and genres of photography. It is often mistaken as a genre of photography but in reality it is a means to achieve certain ends in terms of brightness, contrast, texture and visual flow. Landscape is perhaps the genre of photography that uses this method most commonly primarily to obtain aesthetically delicate images and to deal with light scarcity.
There are many reasons to shoot long exposures in any given outdoor setting. During the day when there is plenty of light, a long exposure is made to use moving subjects to achieve certain visual effects through motion blur to improve the resulting image. However, there are cases where the exposure time would have to be significantly longer to facilitate movement that would take a lot of time for that motion to benefit the visual design of the photo. This is where the use of darker neutral density (ND) filters becomes necessary and tends to be a bit more complicated.
The easiest way to master long exposure times
The basic principle of long exposure revolves around compensation. To be able to extend the exposure time, you’ll have to find a way to limit the amount of light entering the sensor at a given time by using the other two exposure settings ISO and aperture, or you’ll end up losing your exposure. there is an overexposed photo. However, in situations where there is more than enough light, it is not possible to achieve that balance with a significant length of your exposure time simply because even if you lower the ISO as low as possible and If you keep the aperture down to the minimum, you’ll still have more than enough light. In the simplest sense, this is why an ND filter is necessary for long exposure photography during the day.
The simplest way to master exposure compensation for long exposures outdoors is to shoot at dusk when you can make long exposures without having to use an ND filter. By simple trial and error, you will get a good sense of what you can do to adapt to the changing lighting environment. You can then go ahead by using lighter ND filters a little earlier in the sunset such as ND8 (3 stops) or ND64 (6 stops) which will give you exposure time of anything between 2 seconds and half a minute. The game of trial and error mostly gets complicated when exposures are too long and the light can change over the exposure period. This can be complicated at sunrise or sunset when changes in the light environment are rapid, and also during the day when fast-moving clouds obscure the sun intermittently. While experience will certainly give you a much better sense of changes in light and how to adapt to them, determining exposure time based on known factors will certainly give gives you more assurance and shortens the time to learn. The first thing you must understand to be able to do so is exactly how ND filters work.
filter light
To master long exposure, you need to know why you want to do it in the first place. Long exposures have two main purposes in landscape photography, that is to gather enough light in low-light situations and/or use motion blur to achieve an aesthetic effect. When shooting at night, both can be applied if there is an element of movement in the frame that benefits the image, but during the day, the element of movement is often the reason and the abundance of light becomes. challenge. This is where the filters come in.
The neutral density filter restricts light reaching the camera’s sensor during exposure by fractions expressed in stops. By limiting the light that comes in, you can lengthen the exposure time to achieve the same level of brightness so that movement can occur during that time period. The ND filter has different density levels also in stop-stepping. 1 stop in an ND filter halves the light, 2 stops halves the light twice, three stops thrice, etc. The difference of each stop is exponential rather than additive. These filters are usually labeled (with the exception of some manufacturers) as “ND”, followed by a number representing the reciprocal of the amount of light captured. The 3-stop ND filter is called “ND8” and the amount of light captured is 1/8 of the original. The 10-stop ND filter is called the ND1000, which is a rounded down version of 1024 because the amount of light captured is 1/1024 of the original.
You already know that to achieve the same level of brightness as the base exposure (exposure setting without ND filter) you will have to lengthen the exposure. The question is how much longer do you have to extend it? There are three different approaches.
Determine your exposure time
The simplest but most inaccurate way is a simple estimate. This is especially easy when you are using lighter ND filters like ND8 (3 stops) or ND64 (6 stops). Most cameras released in the last decade have come with exposure simulation that allows you to see the results of your exposure before taking a shot as long as there is plenty of light, and it just got a whole lot easier with that feature.
The most accurate way is to calculate with the exact formula corresponding to the filter. ND8 results in 1/8 of the original amount of light, so multiplying your exposure time by 8 will give you the same level of brightness with a relatively longer exposure time. However, it will be difficult to remember the corresponding formula for heavier ND filters. A 10-point ND filter results in 1/1024 of the original amount of light, a 16-point ND filter gives a result of 1/65,536 of the original light, and that’s where memorizing formulas can be tricky slightly.
Simpler approach
Also, there are two ways to make this simple. Since ND filter labels are essentially rounded down versions of the amount of light captured, these numbers that you can find on filter symbols are also quick rounding formulas for you get the right exposure. First, take your base exposure setting (balanced exposure without filter), keep aperture and ISO constant, and multiply your base shutter speed by the numbers on the filter. For example, when using the ND1000 with a base shutter speed of 1/100 second, multiply that by 1000 and your exposure time will be 10 seconds as a result. While using 1024 as the multiplier is more accurate, you just need to adjust accordingly when viewing the results.
The easiest way to get an accurate exposure time, especially if you don’t want to do the math, is to use an ND calculator. There are various smartphone apps such as Photopills and MIOPS mobile that provide this solution. You just need to enter the base shutter speed and the number of stops of the ND filter you are using and the app will calculate it for you.
The best way to master long exposures and ND filters is still to do it over and over again. Whether you’re just interested in observing the situation, using an app, or calculating the exposure yourself, they’re just different means to the same end. Either of these methods will give you the same image quality, and that quality still depends more on the layout, execution, and optical quality of your device.
