How An ND Filter Can Remove Crowds From Busy Shots

When you think of long exposures, the picture that forms in your mind is probably of a waterfall or seascape at dawn or dusk where the water's taken on a milky, silk-like quality but a long exposure can also be used for making moving subjects 'vanish' from your shots. This is useful when photographing architecture in busy cities or when you're trying to capture images of popular tourist landmarks without tourists in your shots. There are times when people can be used to give your images a sense of scale but when you simply want an image of a structure, here's how you can 'remove' them: 

Shutter Speed Choices

How fast the people / objects are moving through your shot will determine how slow your shutter speed will need to be. For the odd person walking through the frame close to camera or for shots where you want to remove moving traffic, a few seconds should be fine. However, in busy city centers where you'll have people at different points in your frame, much longer exposure times are needed and to achieve them, you'll need to fit an ND filter in front of your lens. 

Steady Shot

When using long exposure times you'll need to attach your camera securely to a tripod to avoid camera shake. Adjust the legs before extending the centre column to increase the camera's height as the base will be more sturdy by doing so and use a remote / cable release to fire the shutter. 

Before Attaching The Filter

As composing your shot can be tricky with an ND filter in place, you'll probably want to check your framing is spot-on before fixing the filter in place. Although, it's also worth noting that some cameras allow you to boost the image when using LiveView so it's worth checking your camera settings. 

Exposure

You can either work in AP so all you have to do is select a small aperture and the camera will work out the shutter speed for you or you can work manually, selecting a small aperture and taking a meter reading. After taking your meter reading, select the correct shutter speed and take a test shot, checking your histogram to check the exposure is correct. 

Fitting The Filter 

Fit the filter carefully as you don't want to knock the focus ring then adjust your shutter speed, remembering to take into account your filter's strength.

Trial And Error

To 'ghost' people out of your image you need them to be moving so if someone decides to stand still in your frame then they'll still show up. Plus, if you're working on a slightly overcast day, they sky in the end shot can end up looking completely covered with cloud due to them moving through the frame which might not be a problem but it's worth remembering.