Choosing the right exposure time when using ND filters like Lee Big Stopper or when stacking a couple of filters can be difficult sometimes. For years I was using a piece of paper with a ND filters cheat sheet that I kept in my wallet. Now we are using mobile devices more and more in our photography life so I created a mobile application - an electronic version of my ND filters cheat sheet (or long exposure calculator if you prefer) for mobile devices like Apple iPhone, iPad, iTouch (iPod Touch) and Android devices.

I've got two versions of the ND filters cheat sheet: 'lite' and 'pro' versions. They both are free. Yes, even the pro version is free. Personally I'm using the lite version and not the pro one. This lite version of the long exposure calculator is exactly what I had on a paper in my wallet. It is designed for using with ND8 and Lee Big Stopper filters only as I'm using these two filters only. If you are using other ND filters like 5-stops Singh-Ray Mor-Slo, 6-stops B+W 106 or Singh-Ray Vari-ND/-Duo/-Trio filters you need to use the 'pro' version of the calculator.

How to use it? It's very simple.

First of all visit the following links using your mobile device or use QR-codes below to access the links.

• ND Filters Cheat Sheet / Long Exposure Calculator
• ND Filters Cheat Sheet Pro / Long Exposure Calculator Pro

When you first access ND Filters Cheat Sheet from your Apple iPhone, iPad and iTouch it will ask you if you want to 'Add to Home Screen' doing so will turn ND Filters Cheat Sheet into a Mobile App for you. On Android or other mobile devices you have to add bookmarks by yourself. For the first time you need an Internet connection, but after the first visit it is cached on your mobile device and will be available even without Internet.


Do a light metering with your camera without the ND filter. Set your camera to aperture priority, select the aperture you want to use and take a note of the shutter speed.

For the 'ND Filters Cheat Sheet' find the closest shutter speed to your reading in the left hand column and then read across to column which has the amount of ND filtration you are using ND8 or Lee Big Stopper - this gives you your exposure length.

For the 'ND Filters Cheat Sheet Pro' find the closest shutter speed to your reading in the table header and then go down the number of stops that your ND filter filters. For the convenience on the left hand side of the table you can find your filter names.

Bear in mind both charts use full stops so if your shutter speed is a fraction of a full stop then you need to adjust it accordingly. However on really long exposures slight variations do not affect the exposure that much so you can use the closest value from the charts.

ND Filters Cheat Sheet / Long Exposure Calculator

ND Filters Cheat Sheet PRO / Long Exposure Calculator PRO