“What does a ND filter do?”
In answer to a recent increase in the demand for ND filters, here is a little demo I put together. Basically, the ND filter reduces the intensity of light allowed through the lens and on to the sensor.
When do you use an ND filter?
1. If you want to shoot at a wider aperture (eg. f.2.8) but the light is too bright.
2. If you want to shoot at a slower shutter speed (eg. 4 seconds) but the light is too bright.
3. If you want to shoot at a slower film speed (eg. 50ASA) but the light is too bright.
You get the idea…
At Studio22 we stock the JYC super slim range of ND filters. The key advantage of the super slim filter is that is allows you to add it to your current UV filter without a vignette (on super wide angle lenses you may still experience problems). It also allows you to stack it with another ND filter or a polarizing filter (you may need to remove the UV filter if you stack more than three filters).
*Variable x1000 filters also in stock
Here are a few sample images. The first image in each case is photographed with a faster shutter speed, the second image is captured at the slowest shutter speed possible in that situation (average of about 2 seconds).
Above without ND Filter: Action is almost frozen.
This iPhone photo below shows the Canon EOS 500D with battery grip on a Manfrotto 055 tripod with 804 RC2 head. The 77mm ND4 was on a 16-35mm f2.8 L Series Canon lens.
All slow shutter images were captured at the smallest aperture (F22 on the 16-35mm lens) and slowest film speed (100ASA on the 500D). The job of the ND filter is to reduce the amount of light reaching the sensor to such a degree that the shutter speed can be reduced to 2 seconds or more. I used daylight as my white balance setting. You can see how the images start blue/colder then as the light gets warmer, so do the images.
We stock the JYC ND filters from 52mm up to 77mm in ND2 (1 stop), ND4 (2 Stops) and ND8 (3 stops). I learnt from this test that ND8 is by far my choice for such a bright scene. I would also add a polarizer for a bluer sky and less flare. It will also add to the ND effect and reduce the intensity if light to the sensor.
I hope this was as informative for you as it was fun for me to produce.