There are plenty of resources to calculate changes to the Exposure Triangle and as a photographer you really should be able to work them out in your head. However, sometimes it’s easier to cheat when out shooting so that you can concentrate more on getting those shots than working out exposure times.

As I’m about to try my hand at Moonlit Night Landscapes, a new thing for me, I wanted to be able to take test shots to check for lighting conditions. Moonlit photography can demand very long exposure times at base ISO (the lowest your camera will go without any extended ISOs) which means getting the exposure correct means less time standing out in the dark.

Exposure Calculator in the Play Store

To test for good lighting, you can set the lens to be fully open (lowest f/ number) and bump up the ISO to a high setting, 6400 for example. This means you can take a test shot with the exposure time being seconds rather than many minutes. Then when you have a good lit shot, adjust the aperture to suit and lower the ISO. However, what exposure time do you need?

Well, as a photographer, you should be able to work this out using the Exposure Triangle (Video coming on this soon!), but when making large adjustments of 2 parameters (ISO and Aperture) it can take some time to work out. This is why I searched for an Android App to assist.

As mentioned at the start of this post, there are a lot of resources and apps out there, but Exposure Calculator by Quicosoft for Android is so good I thought I’d share it. Just for the record, I have no affiliation with Quicosoft, I like the app that much I wanted to share it.

If you just want to watch the video, skip to the bottom!

The App is available (Google Play Store) in 2 versions, Exposure Calculator and Exposure Calculator – Donate (see links below), and are both identical with the latter simply throwing a few ¬£/$/‚ā¨ the authors way.

When you launch the App, you are shown the following screen. This is where it’s fantastically simple but powerful.

Exposure Caclulator

All you need to do is dial in your current exposure, make any adjustments to ISO or Aperture at the bottom and it gives you the required exposure time! As you can see in the screenshot above, I have made an example of F/2.8, 1sec and ISO6400 which could be a test shot I explained above. At the bottom, I have changed the aperture to f/11 and ISO to 64 and it gives me an exposure time of just above 27 minutes! You’ll also notice an ND Filter option. The calculator can also tell you what your exposure should be if you are using ND Filters and can even work out using up to 3 stacked ND filters. Also a compensation slider is included if you find your camera isn’t working out to exactly as the App says (more on these are explained in the video below).

Another great feature of this App is that if your exposure time is calculated at over 4 seconds, you have an optional timer to press that lets you know when to close the shutter if you are shooting in Bulb mode. Perfect for my Moonlit Landscape exposures.

Exposure Calculator Timer

The App also comes with an optional night mode which changes the colours to red on black, again, perfect for shooting in the dark as not to hinder your low light vision.

Exposure Calculator Night Time


Watch me take the App for a test drive in the video below!

{Remember to watch in HD if possible}

Links to the Apps;

Exposure Calculator : https://play.google.com/store/apps/details?id=com.quicosoft.exposurecalculator.app

Exposure Calculator – Dontate : https://play.google.com/store/apps/details?id=com.quicosoft.exposurecalculator.donate


  1. Thanks for the helpful video and blog post, but perhaps you could clarify something for me. With your version of ExpCalc there is an Exposure Compensation setting; on my version, which I just downloaded, there is no such setting. Do you know if this feature get removed in the latest version, or is just a matter of knowing how to enable a ‘hidden’ setting?


    1. Hi Terry,

      Thanks for getting in touch. You have pointed out a bug that I didn’t know existed, but then I’ve never used the Compensation feature.

      What I’ve noticed and hopefully is the issue you are having is that turning on/off the “Compensation wheel” option under the “Settings” doesn’t take immediate effect.

      First, make sure this setting is turn on, then when you exit the settings, you will notice that there still is no Compensation Wheel shown at the bottom of the “New Exposure” details. However, what I have found is that if you then reduce any one of the parameter values on either “Current Exposure” or “New Exposure” the wheel magically appears. This is also the case if you then turn off the option. I’ve noticed that you always have to reduce a parameter value, increasing a parameter value does work.

      Hope this helps.

      1. Just wanted to put a bow on this by confirming that the developer did indeed respond quickly, but not before I had been notified that an update was available from 2.5.0 to 2.5.1. The update seemed to resolve the problem, so I’m happy. It’s a nice, useful app with hint of, um, personality.


      2. Just to put a bow on this for anyone else reading this, the developer does appear very responsive and willing to help, so that’s good. In my case, though, almost immediately after I left my message with him I received an update notification for the app, so I updated from 2.5.0 to 2.5.1. Once that was completed, the app functioned as expected, in all respects. Go figure.


  2. Excellent et très bonne application utile et complete.
    juste une am√©lioration pour le timer. la sonnerie ne dure pas assez longtemps, qu’une fraction de seconde. un peu plus long serait mieux.

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