Practical Advice About ND Filters Part IV

• Exposure control
• Shooting of the Sun
• Choosing the ND filter
• Conclusions

Exposure Control 

If you are shooting video, for example, with a frame rate of 25 fps, it is recommended that you set the camera shutter speed to the inverse number of about 1/25 sec. But in sunny weather, this is almost impossible as your footage will be overexposed. 

The only thing you can do is to speed up the shutter speed but this will cause the final video footage to appear jerky. However, by using ND filters you can reach the desired light flux for the optimal shutter speed.

Shooting The Sun

As well as capturing timelapse footage of the sun, you can also shoot video footage when the sun is near the horizon and again, you'll need an ND filter to cut an extra light flux.

Choosing An ND Filter

As we've worked our way through all of the ways an ND filter can be used, we'll now look at how we can choose one that's right for us. 

If you have a sufficient budget and will be using long exposures, we recommend you use a set of filters rather than just one. First, you need a filter high-density level like an ND500 or ND1000 with 9 and 10 ND f-stops. You'll also need another type of filter if you plan on slightly adjusting the exposure (about 2-5 f-stops), and for this, we recommend you use a variable ND filter. Plus, when you need to achieve a very long exposure time, you can make a 'sandwich', combining both filters together so that you get 15-17 f-stops.

You should pay attention to the quality of variable density filters because cheap variable ND filters can create poor sharpness levels. Sticking with well-known and respectable brands will prevent this from occurring and Kenko has two models that are suitable: Kenko Variable NDX filters for professional photographers and Kenko PL FADER filters for amateur shooters. 

If you're on a slightly tighter budget, we recommend using filters with a fixed ND level. For portraits with fast lenses, we recommend you use a filter with a rating between ND4-ND16. This will give you a good amount of depth of field even on sunny days.  

If you are interested in long exposures, for example for shooting landscapes and cityscapes, filters with ratings between ND32-ND200 will give yu adequate shutter speeds, even on sunny days, and for those who need much longer shutter speeds, we recommend using ND500 and ND1000 filters that give 9 and 10 f-stops. Alternatively, you can combine different filters to change the density and as a result, the exposure length. For example, by combining ND and ND1000  you get 13 f-stops while an ND32 and ND500 together gives 14 f-stops.

Using filters with fixed ND levels is  less convenient, but you can achieve any shutter speed you like, giving you more creative control and better image quality (in terms of resolution and colour).

Conclusion

In this series, we wanted to look at ND filters in a simple, but still detailed way so amateur photographers can grasp a better understanding of what they are and how they can use them. There were some points we didn't touch on, for example, we didn't speak about half-ND filters or about the colour shift that can occur in some ND filters, but we hope you found it useful none-the-less. 

We hope this series was useful and inspires you to experiment more with your photography. 

If you missed the previous 4 parts, take a look at them by clicking the below links:

• Part 1
• Part 2
• Part 3