We understand. You saw all those amazing shots of Paris, and you booked a trip. You wait in anticipation, eager to photograph the sights.
Arc de Triomphe, Notre-Dame de Paris and even the Eiffel Tower are on your shot list. The first things you will shoot, even before breathing.
The day finally comes. Your room checked-in, your bag on the floor as you run, gasping for air, towards the bottom of the Iron Lady.
You screech to a halt, full on panic mode. Tourists swarm the entire area. Oh no. How will you get that perfect shot?
None of those images you saw had any tourists.
Well, at Expert Photography, we can’t do much about the people. We can recommend that if you want them out of the way, you can either shoo or shoot them.
We prefer the latter and hope you do too. By shoot them, I mean photograph them. Keep them in the scene. We have the perfect way to make them disappear in-camera, without any editing.
This means you don’t have to wake up at the crack of dawn. All you need is a camera, a tripod, a few Neutral Density Filters and some patience.
A long exposure is an exposure from your camera (a photograph) that happens over a long period of time. What this allows you to do, is blur out the moving subjects.
Low-light conditions are where we use long exposures. Here, the extra time exposing a scene increases the amount of light that hits the sensor.
It can also show movement. Blurring either the subject or the background, keeping the background or the subject frozen in time.
A long exposure in a world of tourists means being able to capture that scene showing only static subjects. Statues, buildings and towers are perfect choices.
Now, a long exposure means increasing the shutter speed past what we would call standard (1/60th).
This is the cut off between being able to use a steady hand (1/60th>) and requiring a tripod (<1/60th).
Anything below 1/60th will give you camera shake, blurring your image.
A long exposure will blur the tourists, cars, animals – anything that moves. They become blurred because the scene is a 15 second long image.
In that time, the subject, or tourist, has moved from one area to another. Their outlines are not so familiar any longer.
18.75 metres is the average time adults walk in 15 seconds, which could be in and out of the shot before it has finished capturing.
A long exposure adds light, right? Well, what if it is a sunny day? You have three areas that work co-dependently to capture and record light.
ISO, shutter speed and aperture all affect the amount of light hitting your sensor. Together they make up the exposure triangle.
A sunny day will push your aperture to f/22 (more than likely the maximum) and your shutter speed to about 1/6th.
An aperture of f/22 is the maximum and most light limiting, so is ISO 100. This is why we work primarily with changing the shutter speed.
ISO should stay on or around 100, as this holds the quality of the image. That will give you a tiny amount of blur, but not enough
Any tweaking with the shutter speed will make the picture overexposed and burned-out. This ensures the image will lack detail. Increasing the ISO results in loss of quality.
So, what can we do? Well, you need something to bring down the amount of light hitting the sensor. This is where the ND filter comes in.
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An ND or Neutral Density filter stops light from entering the lens and hitting the sensor. These fit on the front of the lens with the help of an adapter.
Or you can buy these ND filters that clip on the inside of your camera body. This can be very helpful, and we will look at this later more in-depth.
The adapter that holds your ND filters typically needs a ring to fit onto your lens. Most manufacturers provide these rings, ranging from 49 mm to 82 mm.
The ND filter looks like a square of dark glass. You can buy graduated ND filters, but these are for sunsets, and bringing down the light from only part of the scene.
Many companies sell packages of the adapters and rings, and a whole range of ND filters and graduated filters together. Your father might even have some Cokins lying around.
The ones I use are from Rangers, and they provide 4 ND filters and 4 Graduated Filters (2, 4, 8, 16), 9 Filter Adaptor Rings (49-82mm), ABS adapter, all in a nice pouch.
ND filters are quantified by their optical density. Or a little simpler, their f/stop reduction. An ND16 filter will lower your f/stop by 4 stops.
Instead, you can lower your shutter speed, which is more beneficial for long exposures.
Using The ND Filter to Remove People
The idea is to remove the people by creating a long exposure, therefore, blurring out the moving subjects. Static objects need to be unaffected by wind for the best results.
Set up your scene, lower your ISO to its minimum (50 or 100), then change your aperture to your desired focus. A higher aperture will keep everything in focus.
Move your shutter speed to the slowest speed possible while maintaining a correct exposure. A bright, sunny midday might give you ISO 100, f/22 and 1/6.
This isn’t enough to get that blurry fluidity you are looking for. You must also:
- Make sure the adapter ring is screwed on to your lens well, via the thread;
- Clip on the ABS adapter to the ring, in a way that allows you to slot in the filter sideways;
- Start with the ND16 or high number ND filter;
- Lengthen or slow the shutter speed down to account for the change in light.
From here, one of two things will happen. The first is you will have your image where the people have vanished from the face of the earth. Good job.
The second is that the filter isn’t strong enough, and the people haven’t vanished. Boo. By the way, are you trying to capture the sun?
From here you can go one of three ways. You can give up and try a different way. You can start to stack your ND filters in your adapter or wait until the scene becomes a little darker.
Stacking ND Filters
Stacking ND filters is the act of placing more than one filter in the adapter. The sun was so bright when I went out to experiment, my ND16 wasn’t enough.
I added the next biggest size I had, which was the ND8. This still wasn’t enough to completely blur the subjects. I then added the ND4.
This was a total of ND28, just under the 5 stop mark. This seemed to do the trick in blurring the subjects enough, but as a consequence gave me interesting results:
- I noticed the edges of the frame looked as if they were not covered by the filter. I double checked, and they were still there;
- The image had a pink cast over it, which is common with ND filters made from resin;
- The stacked filters reflected the lens into the image;
- The sun created reflections that caused sun spots and lens flares;
- The reflections must have also bounced around among the stacked filters and created a Jackson Pollack of lighting on the image.
- The images’ contrast was considerably lower than the base image.
- The focus became soft.
The pink hue over the image can be changed digitally, and the vignetting can be cropped out, but then you need to take that into consideration.
The other 5 disadvantages can be solved as easily. I spotted some of these problems while shooting, and tried to hide the camera and the filters in the shade.
This had little to no effect, which meant that only the placement of my hand could stop the flares and sunspots. This, however, added to the camera shake.
Lee Filter’s Big Stopper: ND 6 stops
My first idea of tackling this situation was to look for the most amount of human traffic. A zebra crossing was the ideal choice, right in the sun at 1pm.
As I had tried to stack ND filters which accumulated to just under 5 stops, I decided to go stronger and use the 6 stop ND filter.
Keeping the ISO and the f/stop equal between both images, the first image shows some movement from people.
But from photographing the same scene, the furthest I could push the camera settings was to 4 seconds.
This was not long enough to remove the people from the scene.
Conclusion: The scene was too bright for the ND 6 stops to work efficiently. Also, static subjects are more apparent in such a short period of time.
Before ND Filter – 38mm Lens Canon 7D. Octagon, Budapest. 1/40 – f/stop 22 – ISO 100
After ND Filter – 38mm Lens Canon 7D. Octagon, Budapest. 2 Seconds – f/stop 22 – ISO 100
After realising the bright areas limit the shutter speed to two seconds, I found a shaded area with substantial human movement.
The shade was around 1.5 stops darker than the sunlit area, which allowed me to push the shutter speed of the base image to 1/13th of a second.
The image using the ND filter allowed me to capture the scene at 4 seconds. This was ample to remove the people from the image.
This was down to the slower shutter speed, but also due to the location. The area of human movement was smaller, so people moved in front of the camera faster.
In the ‘after’ scene, approximately 12 people walked in front of the camera, all uncaptured.
Conclusion: Smaller areas allow you to remove the people as the area is smaller for movement. A person could walk into and out of the frame during the exposure time.
Before ND Filter – 38mm Lens Canon 7D. Octagon, Budapest. 1/13 – f/stop 22 – ISO 100
After ND Filter – 38mm Lens Canon 7D. Octagon, Budapest. 4 Seconds – f/stop 22 – ISO 100
I wanted to see what would happen when photographing a larger area in the shade.
The base image had a slower shutter speed than the previous experiment, which came in at 1/8th of a second.
You can clearly see the movement from the people, and the static, sharp image of the homeless man, sitting on the floor.
The ‘after’ image had a shutter speed of 30 seconds, but it still wasn’t enough to remove all of the people in the scene.
40+ people walked in front of the camera while it was capturing the scene. You can also see those who are standing still easily.
Conclusion: A wider area allows the possibility of more people, making it more difficult to remove them.
It also gives way to the probability of people standing still. These people are impossible to remove via the method of an ND filter coupled with a long exposure.
I also noticed that the wave of people sucked out contrast from the image. This can be dropped back in later, but extra post-processing time is needed.
Before ND Filter – 38mm Lens Canon 7D. Octagon, Budapest. 1/8 – f/stop 22 – ISO 100
After ND Filter – 38mm Lens Canon 7D. Octagon, Budapest. 30 seconds – f/stop 22 – ISO 100
The Neutral Density filters can be a little tricky to use perfectly. Make sure you have a cleaning cloth handy as they attract a lot of dust.
Use the ND pouch for them as much as possible, and if you don’t have one, get one.
Given all the problems I experienced, I doubt I will stack the filters again. Too much post-processing hassle for one image.
The other possibility is to buy a 10 stop ND filter, made out of glass instead of resin. Lee Filter’s Big Stopper is a 10 stop ND filter, yet it costs $125.
A 10 stop ND filter will give you more room to play with your shutter speed, and it might be perfect for bright areas.
A way around this cost is to DIY a 10 stop filter yourself. Welding glass from a hardware store can be used and can cost as little as $5.
You will need to take some extra steps to colour correct the tint, and this can be a little finicky. You did just save $120, so it’s not all bad.
Another possibility is to take multiple images, stack them together and mask out the people. This can be done in Adobe Photoshop.
You ensure there are no people in your image, not even as streaks. This might take less time than the 10 stop ND filter would (32 minutes!)
After experimenting a few times with the ND filters, there are a few words of advice I would like to pass on.
Try not to shoot in spring or summer, when the sun is at its highest and brightest. These images were taken on the 3rd and 4th of May, around 12-2pm.
If you have to, look for the shaded areas first. Don’t shoot directly towards the sun, as the extra glass will cause lens flares and spots of light.
Have the sun behind you. Try to stick to small areas, as people will stay for a shorter time in your scene, allowing an easier and faster flow.
If you do need to photograph a wider area, then use a very high ND filter. Go for the 10 stop glass ND filter.
These can be stacked, and the glass will fare better than the resin ND filters.
You could also create a composite, focusing on smaller areas and then stitching them together in post-processing to create the larger scene.
Be aware of the people as much as you can. Watch for areas where people might stand still for more than a second.
All in all, if you are photographing a scene, try to go when the human traffic is not at its highest for the best results.
Still interested in learning more about ND filters? Check our article on using neutral density filters for landscape photography!