More image sharpness with Focus Chart

The app developer Distant Blue Mobile Solutions offers users an app with two different patterns, both of which are labelled with the Siemens star. This allows users to quickly match the focus area of their own camera with the respective object and don’t even have to pay a euro for it, as the app is offered free of charge for Android and iOS. Whether the app is worth using is explained below.

There must be a catch if an app is available free of charge and no adverts are placed in it whose content comes from an advertising campaign. Users might ask themselves this when using the Focus Chart app. In fact, there is only one advert, and it relates to a major product of the app developer, namely the Cadrage Directors Viewfinder, a production planning tool that generates revenue. The advantage is that the advert is not obtrusively in the foreground, but only plays a secondary role in the app. It appears as you browse through the Siemens stars and disappears just as quickly.

Solid basics

What the app offers users are basically two high-resolution charts with a Siemens star. One full screen and one with additional test patterns around the Siemens star. In terms of functionality, the user can change the pattern by swiping to the left or right and exit the app as usual. That’s it for the functionality, you could also call it a solid basis at this point.

Accordingly, the tests were also solid, almost rudimentary. It is important to have a tripod with the appropriate tripod head and clamp in stock so that the tablet – which should not be too small – can be fixed in the clamp. Ideally, the tablet should have a high-resolution display, high brightness and good contrast. Of course, the touch surface should be clean and the power-saving mode should be deactivated. Then the way is paved for calibration.

Of course, the app is not as sophisticated as the Datacolor SpyderLensCal Set for 59.99 euros, for example, but as a free solution it helps to quickly calibrate the autofocus better. Especially when several object changes have to be carried out on a B-unit system. For calibrating the front and back focus of professional cine lenses, however, we recommend switching to the Datacolor system, for example.

Nevertheless, the Focus Chart app is installed on your own Android or iOS device, does not consume any power as there is no connection to an advertising turret, and the app is at least updated. An initial test version of the app only contained one sample; a second was added as development progressed. With more user participation, more patterns will certainly be added. And perhaps with more users, the app will also be further developed in such a way that a Bluetooth connection to certain cameras is possible and lens information can be exchanged with the app. Until then, however, it is important to familiarise yourself with the two good test samples and adjust the autofocus on your own cameras or check the focus of your own lens set. The app can be downloaded from the respective stores – App Store and Play Store. At the time of testing, the app was free of charge, and so far there is nothing to suggest that this will change in the near future. And perhaps one or two users will take a look at the app for production design.