Flash Photography Adviser
iOS Universel / Photo et vidéo
The Flash Photography Adviser app automatically proposes balanced settings, and subsequently supports changing these settings to achieve a new equilibrium, for:
- Flash Coverage (Zoom),
- Flash Output (Power Level),
- Flashgun-to-Subject Distance,
- Camera ISO,
- Camera Aperture,
assuming a shutter speed that is at or below the camera's maximum flash sync speed, and where the flashgun-to-subject distance is measured along the path that the light travels from flash to subject.
Each such an equilibrium represents a correct exposure in accordance with the guide number rule.
The guide number rule is a handy rule of thumb in flash photography; the rule estimates the required flash exposure value without using a light meter.
This rule evolves around three concepts:
- Incident light (as opposed to reflected light); an advantage for `difficult' subjects (for example bright or dark scenes).
- The different lighting conditions that occur when (a) zooming your flashgun, (b) changing the flash-to-subject distance, or (c) changing the flash power
- The relatively fixed exposure value for the light from the flashgun under these conditions
What the rule does NOT prescribe are the actual flashgun and related camera settings (aperture, ISO, flash power, flash zoom, flash-to-subject distance) that you can use, as long as the combination of manual flashgun and camera settings lead to an equivalent exposure value as specified by the rule. Often, there are many of such equilibria.
The Flash Adviser will assist in finding these equilibria by indicating how to achieve balance (the deviation as well as the direction), and indicating when balance is achieved. For this, the app indicates the resulting overall exposure value in stops RELATIVE to the rule for a selected lighting condition.
Also, in the balancing process, you can choose to balance to a flash exposure compensation value rather than balancing to the zero value. For instance, you can use this feature for compensating for specific light modifiers (e.g., a shoot-through umbrella, a softbox) or to achieve balance between flash light ambient light.
In this convenient app you can define and store your own flashgun(s). The app estimates the required exposure value based on the (zoom-value dependent) guide numbers of the flashgun. These guide number values can often be found in the specifications section in the User Guide of your flashgun, and can be stored in the app when defining your flashgun.
The app can also be used as a `training device', where you first guess the required combination of settings for balance, and subsequently check these with the app.
Further characteristics:
- No in-app purchases
- No account, no login
- No advertisements
Quoi de neuf dans la dernière version ?
This version includes three example flashguns for demonstration purposes. These example flashguns are not shown when other flashguns are already defined by the user in a previous version of this app. The example flashguns can be deleted, but they can also be edited to transform them to flashguns that are relevant to the user.
This fully redesigned version of the app provides increased flexibility to the user, so that any combination of settings may be used incrementally to achieve or maintain exposure balance. In order to support this increased flexibility, the app indicates the amount of unbalance as well as the direction of the unbalance (if any).
