Simplifying Hyperfocal Distance, Depth of Field and Neutral Density (ND) Filter Calculations Using Your Smart Phone

Most of us today are using Smart Phones today in our daily lives, some things the Smart Phones do not do very well and other things the Smart Phones do very well.

Smart Phones are extremely good at simple computer type calculations and coming from an Engineering background I really like to get the calculations correct when the final photographic image may depend on the calculations, this is where the Smart Phone can excell.

Smart Phones are not very good at competing with a Digital SLR to produce superb image quality, the sensors in a Phone are very small and the pixel density for a given sensor area is huge compared to a larger  camera and consequently the signal to noise ratio is just not good, particularly in poor lighting situations. We see every day examples of poor quality Smart Phone images on social networking sites such as Facebook.

I have done a few previous Blogs covering Tips on Using an Android Device to Help You in Your Photography and also Using Your Smart Phone or Tablet GPS System, to Geotag Your Nikon Images. These Blogs are some examples of how a Smart Phone can assist you.

In this Blog I have another few examples of using your Phone to help you get better quality images.

Hyperfocal Distance

Understanding “Hyperfocal Distance” can help you greatly in understanding “Depth of Field” and the section of the image scene that is in focus with the particular lens settings you are using. Focusing your camera at the hyperfocal distance ensures maximum sharpness from half this hyperfocal distance all the way to infinity. The hyperfocal distance is particularly useful in landscape or seascape photography, and will help you make the most of your  in focus “Depth of Field.”  This will result in a more detailed resulting image or final print.  Knowing the hyperfocal distance for a given focal length lens and aperture setting can be very tricky.  There is an excellent Andriod App that can illustrate this and do all the “Hyperfocal Distance” calculations for you.

The App I use for this is HyperFocal Pro, this App provides a  provides a hyperfocal distance chart, calculator and a drawing showing the area which is in focus together with distances.  A screen shot is shown as follows.


In the above screen shot the camera used is the D810, the lens focal length is 15mm, the aperture f/2.8, the Hyperfocal Distance is 2.778 metres, the near focus limit is indicated as 1.442 metres and the far focus is at infinity distance. This really simplifies the calculation.

ND Filter Timer

Another App I use on a regular basis is ND Filter Timer. This App will calculate the increased shutter setting required when using ND (Neutral Density) filters. A screen shot of this App is shown below.


Here if the shutter reading is 1/25 second and we have ND filters to the amount of 14 stops then the corrected shutter speed will be 10 minutes 55 seconds as indicated with the App. and this App has a timer built in to let you know when the exposure time is up.