LExp or Long Exposure Calculators is an iPhone and iPod touch application and it is a collection of different calculators and reference tables/cheat sheets (including well known and quite popular ND Filters Reference Tables) created to help photographer with shooting long exposures with Neutral Density (ND) filters, in low light and at night.

Application includes:
- Neutral Density ND Filters Reference Charts / Cheat Sheets
- Calculator for stacking Neutral Density ND Filters
- Calculator for Graduated Neutral Density GND Filters
- Shooting Flowing Water Reference Charts / Cheat Sheets
- Shooting Fireworks Reference Charts / Cheat Sheets
- Calculator for shooting under Moonlight
- Calculator for shooting star-trails
- Calculator for shooting still/non-moving stars
- Calculator for Velvia 50 reciprocity failure
- Useful resources and links on low-light and night photography

Built-in Timer: Some calculators have built-in timer for your convenience. It is automatically enabled when your exposure is 30 seconds or more.

Alarm in Timer: You will be notified at 20, 10, 5 and 0 seconds when you are using countdown/timer.

Favourite Calculator: Lock your favourite screen for quick access when you opening the application.

Additional Info: Almost every calculator has some additional information about filters, used formulas, techniques etc. If a calculator is just a table than additional info is located below the table.

If you have something to add and think it could be valuable for others please contact me. I'll review and hopefully add it in the next release of this app. If you found any incorrect information or a bug or have a suggestion then please contact me as well.