The HDR Exposures Calculator app is for photographers who are capturing a scene with a particularly high dynamic range (an interior with a bright view through the window, for instance) and who want to get the best quality output.
The app helps determine the exposures you need to capture to get the best merged HDR result.
The app is only needed when you are taking a scene with high or very high dynamic range. It isn't needed for an outdoor scene, except in specific cases.
The HDR Exposure Calculator can also be used as a learning tool (until it's not needed anymore). The app visualizes the process of determining the exposures needed. This leads to a better understanding of HDR photography image capture, making it then easy to figure out the exposure settings without the assistance of the app.
The web version of the app (at hdrsoft.com/ev) downloads a small amount of data when you open it, and then does all its calculation offline.
This means you can use the web app even with a poor data connection. If you don't have any Internet connection while in the field, then just make sure you have a browser page open with the HDR Exposures Calculator on your smartphone before leaving to a location without Internet.
If the browser on your mobile phone or tablet attempts to reload the app's page when you use it in the field, then cancel the refresh to prevent the page from reloading. If it has already reloaded and you now have a blank page because there is no Internet, then use the browser's Back button to get the HDR Exposures Calculator back.
Photos taken with more than 2 EV between them don't provide a sufficiently good coverage of the tonal range to ensure a high quality merged HDR image.
Since the HDR Exposures Calculator is intended for photographers who need high quality results as outlined above, we thought it would be misleading for the app to support 3 or more EV spacing.
Not at this time, though we may offer an Android version of the HDR Exposures Calculator app later on.
However, you can use the web version of the app right now, in a browser on your Android phone.
See more info in the section on using the HDR Exposures Calculator in the field.
Yes. The iOS version of the HDR Exposures Calculator app is now ready and should be available on Apple's App Store in March of 2018.
If you don't want to wait for it, or prefer not to have to pay for the app, you can use its web version in Safari, or any other web browser on your iPhone. See more info in the section on using the HDR Exposures Calculator in the field.
The web version of the HDR Exposures Calculator app (hdrsoft.com/ev) is free of charge, and doesn't collect any data or personal information whatsoever.