Using a 10-Stop ND Filter for Long Exposure Photography

Long Exposure Photography Using ND Filters

Step 1:

Mount your camera on your tripod and compose the scene.

Step 2:

Put your camera in Aperture Priority Mode. Set your camera’s iso to its lowest native setting and set the aperture to F8 to F11. Mid apertures from F8 to F11 usually work better than stopping down further to something like F16 or F22.

Step 3:

Put your camera in live view mode and, if your camera has an optical viewfinder (OPV), cover it so no extraneous light can enter through it. Extraneous light entering through an optical viewfinder during the exposure is called a light leak, and will produce an image with a green to purple color cast. If your camera has an electronic viewfinder (EPV) you won’t have to worry about this issue, so covering the viewfinder is not required. Next, focus and take a picture with the filter OFF. Verify that this image is composed the way you want it and focus and exposure are correct.

Step 4:

Gently screw on your ND filter being careful not to alter the zoom on the lens or your composition. With the filter on, focus and take the image.

Step 5:

Chimp the shot and verify that it’s exposed properly and that you camera focused as expected. If it did, you’re done! If not, go back to Step 3, and repeat. If you’re still experiencing an issue, proceed to step 6.

Step 6:

Issue #1

If your result from step 5 is a blurry picture, then your camera likely cannot auto-focus with the 10-stop ND filter on the lens. If this is happening, you’ll need to focus with the filter off, then after focus is achieved, put your camera/lens in manual focus mode, attach the filter, being careful not to alter focus or zoom, then take the picture.

Issue #2

If in step 5, you find that you’re getting a 30-second exposure and the resultant image is underexposed, you’ll need to do the following:

• Put your camera in manual mode
• Enter the iso and aperture that you used on the image you took when the filter was OFF
• Use a Smart Phone app such as NDTimer to determine what shutter speed you need to use to achieve proper exposure. With these ND apps, you enter the shutter speed you’re getting when the filter is off — so, look at the image you took when the filter was off and note what shutter speed your camera used to properly expose that shot. Enter that shutter speed into the app then enter the type of ND filter you’re using. The app will tell you how many seconds long your exposure needs to be when the ND filter is ON the lens using the same iso and aperture you used with the filter off.
• Put your camera’s shutter speed in bulb mode. In bulb mode, the shutter will stay open for as long as you keep the shutter button pressed in. Most ND Timer apps will include a stopwatch feature allowing you to properly time the shutter speed. Continuously depressing the shutter button can induce camera shake, it is recommended that when shooting using bulb mode, that you utilize a camera release so you’re not touching the camera during the exposure.
• With your camera in manual mode, using the aperture and iso settings you used when the filter was off, put the shutter in bulb mode, then take the image keeping the shutter open the length of time the app indicated.

Note that if you’re experiencing Issue #2, you’ll likely also be experiencing Issue #1 so you may have to do what is outlined for Issue #1 and Issue #2.