Technical Camera did support longer exposures (up to a given device’s capabilities, which is usually in the 0.5s-1s range) from day one. And live view frame rate followed the exposure time, resulting in substantial lag when longer exposures were used.
To resolve this issue, version 1.4 introduces exposure simulation.
It works exactly the same way your regular camera’s live view does: we simulate the brightness of longer exposures by increasing ISO instead of dropping the shutter speed. The result is a fluid, high frame rate live view feed under all circumstances.
There’s a limitation, though, that you should be aware of. When light levels drop, simulation may end up showing a darker image when the actual (non-simulated) exposure would also use a very high ISO. Practically this isn’t a big deal, since very high ISOs are unusable on a phone.
Update 10/2/2019: While it’s a version 1.5 feature, the exposure simulation warning should also be mentioned here. It appears when the simulation can no longer show the actual exposure, because it hit the high ISO limit.
In this case an orange dot starts to blink once a second.
Exposure simulation is always on, no way to disable it.
Version 1.4 is a free update for existing Technical Camera owners. New users can purchase the app in the App Store.
