Long Exposure.
The technique, not the crime.

Long Exposure. The technique, not the crime.

Firstly, forget everything you’ve ever known about long exposure. The first half of this blog is designed to take a stripped back look at bare bones straight out of camera Long Exposure. I will cover technique briefly, but this should be considered more of a recipe. The second half will touch briefly on filter systems, although I don’t want to get too into this as not everyone can afford a filter system.
If you look at my Instagram feed you’ll see a lot of images taken of streams, rivers and waterfalls – all Long Exposure shots. But, except for a polarizer in a handful and a neutral density filter for one, yes one, none of them are shot with filters. You could argue that the polarizer does slightly darken your exposure times and I’m cheating but to the letter of the law here these tips will work 90% of the time straight out of camera or your mone…..nevermind, it’ll just work ok.
So first, we need to do some theory. Free knowledge guys, drink it in! How long is a Long Exposure? The fact is, there is no concrete definition of a Long Exposure image. Some will say at least 5 seconds, others will say 30+ seconds. I however define it as anything lower than 1/60th of a second. Why? Because that’s the lowest shutter speed at which you can handhold a camera before you begin to see camera shake or blur, therefore you must use a tripod to steady the camera. For me, if you have to use a tripod then it must be a long exposure. Flawless logic!
A noticeable difference in the water even though the shutter still hasn't gone over 1 second
I also explain it this way because many people think you need expensive filter setups and loads of different filters to achieve a Long Exposure image. You may need that kit to stretch out the clouds in the sky or smooth out a rough lake, but for those of you looking to blur a wave or have a stream turn milky white more often than not 1/30th of a second is enough. Whoops, secrets out…
You’re probably thinking to yourself ‘how is 1/30th of a second a Long Exposure’. Well, let’s look at what happens during the 1/30th of a second. The camera works by dropping a shutter to let light hit the sensor. The shutter covering the sensor drops as soon as you press the shutter release. Depending on your shutter speed, another shutter will drop down behind the first shutter that exposed the sensor to now block the sensor and finish the exposure. With me? No? Watch this and it might help, I’ve started from a specific point in the video but I would recommend watching the whole thing when you have time.
Just come back to my blog k. Watched it? Good, we may continue!
During longer exposures it’s easier to see the effects of Long Exposure, anything moving in your image that changes from one position to another by the time the shutter closes will look blurred across the image from the start position to the end position. The length of the blur is entirely dependent on the speed of the object and the length of the shutter speed. We’ve all seen pictures of car lights being stretched out through a scene. That’s because the car is moving much faster than the shutter speed. While the shutter curtain is open the sensor is exposed to the lights of the car. At every point the car lights cross in the scene they are imprinted on the sensor, so it appears to stretch out, that’s where the trail comes from!
Caption: The car lights stretch out like this because they move across the scene while the camera shutter is still open
Now we kinda understand what we’re working with here, lets jump into the recipe for lovely river, waterfall and seascape shots. We’ll break it down by each part of the recipe.

1.  Aperture: Use F11. Don’t use a lower aperture. Logic dictates the higher the aperture the more depth of field in your image, but what actually happens at higher apertures is a thing called diffraction. You do get more depth of field, but you lose a significant amount of sharpness. So F11 will block enough light for us without degrading our image! If we need to block more light we will go to F16 later.

2. ISO: Has to be ISO 100. ISO 100 has many benefits. It has the most dynamic range of all the ISOs, it gives the cleanest image with the least amount of noise and it’s also the least reactive to light. If your camera has the option of ISO 50, use that.
3. Shutter Speed: Set your camera on ‘A’ ‘Av’ or whatever it may be. This allows you to set your ISO 100 and aperture at F11, the shutter speed will then be dictated by how bright the scene is, remember how the camera is trying to balance the histogram? If you don’t like the effect the shutter speed is giving you you can go to to F13/F14/F16 to block more light making the shutter speed longer. To make it shorter go to F10/F9/F8. This will affect depth of field, but not drastically.
It’s important to note that this recipe will not work on a bright sunny summers day with the sun splitting the stones. For me the ‘slower’ Long Exposure times of 1/5th or 1/20th on flowing water work the best anyway. This technique will work perfectly for that under shade or cloudy skies. We get a lot of them here in Ireland.

So what do you do on a bright sunny day? Or if you want to get ridiculously long exposure times? Filters. Filters are colour neutral darkened pieces of glass or plastic that act almost like sunglasses for your lens, blocking out sunshine to allow the camera to keep the shutter open for longer. Unfortunately, it’s an unavoidable expense if you want to do Long Exposure photography during the day. The most common filters for Long Exposure are Neutral Density and Graduated Neutral Density filters. These filters come in varying strengths depending how much light they block from your lens. There’s always heated debate over which filter company to choose! I’m not going to get into the Nisi V LEE V Cokin battle. Too many arguments to be had and I think everyone should do their own research and decide on a product that suits them, don’t be swayed by influencers and promo codes, attempt to try before you buy and see which one is the best by performing rigorous and strenuous tests with varying controls and demands on each product. Or just buy the Nisi V6 filter holder and be done with it. It has a fantastic integrated polarizer with a handy little wheel to turn it. Fabulous system and very easy to setup and use. Buy it here https://www.filtersforcameras.com

The older Nisi V5 filter holder is the best I've used. The integrated cog system to spin the polarizer is nothing short of genius.
This blog was a lot of fun to write. There is a lot of information to try and get across for this subject. I’ve tried to take a different approach to show the more accessible side of Long Exposure! That’s not to say that use of filter systems should be ruled out. Just make sure you have a firm grasp of the concept and the technique before making an investment in a good (NISI) filter system.
As always, thanks for reading! Sharing, comments and questions very much welcomed and appreciated.

Thanks for reading!

Ronan Harding Downes

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