TrueDoF-Pro offers the advanced depth of field calculations unique to the TrueDoF range of apps, and adds the versatility, customisability and usability to make it the ideal tool for professional photographers and cinematographers.TrueDoF-Pro differs from other DoF calculators in that its algorithm for calculating depth of field includes the effects of diffraction. This gives the user a MUCH MORE ACCURATE indication of how sharp the image will be. This is a major advance in depth of field calculators. (See the important note below regarding the practical effects of this.)The primary mode of display is the analog scale, making it so much easier to see, with a mere glance, whats going on and how things change as you change inputs. Add to this the extraordinarily fast input methods, and you have a DoF calculator that simply does its job and gets out of the way.Although built on TrueDoF, the Pro version is in a completely different league, with important additions that make the app a great tool for professionals and enthusiasts:* User-definable focal length presets, for even faster selection of focal lengths* Versatility in setting target image quality - set blur spot diameter (circle of confusion), or set print quality* Indication of maximum achievable depth of field and the aperture that results in that maximum* The facility to specify wavelength, an indispensable feature for those who are shooting in the infrared (or ultraviolet) parts of the spectrum* Three user-selectable distance scales* Two user-selectable aperture scales* Optional input of focus distance via keypad* Aperture slider snap to half or third stops* Larger, easier-to-read digital readout display* Designed for use in cinematography as well as photographyCarried over from TrueDoF are such features as the hyperfocal function - a tap of the HF button sets the focus distance so that the far limit of depth of field is at infinity. While the function is engaged, the focus distance and the near limit of depth of field change on the distance scale as you change focal length or aperture.The additional features, rather than adding to complexity, simply add versatility and allow customisability that actually makes the app much faster and easier and more pleasurable to use - youll never go back to another depth of field calculator.IMPORTANT: Please be aware that, at particularly large f-numbers, diffraction effects become quite pronounced and result in DIMINISHED depth of field. Indeed, at a large enough f-number, the depth of the region of acceptable sharpness drops to zero. This is because, at such an f-number and above, diffraction produces so much blurring that the sharpness standards you have specified on the settings screen cannot be met. For more on this, see the article "Image Sharpness vs Aperture" at www.georgedouvos.com. A note on intended use:TrueDoF-Pro is designed for professionals who want an accurate, versatile and easy way to calculate the depth of field produced by their chosen camera settings.In many situations, however, it is best to work quite differently: Compose your shot, specifying the distances to the nearest and furthest objects that you wish to appear sharp in your shot and, from that, have an app determine the camera settings (focus distance and aperture) that will give you the SHARPEST POSSIBLE IMAGE. For that, there is only one app: OptimumCS-Pro, the unique optimum camera settings calculator, also available on the App Store.And, if you would like to achieve insanely huge depth of field - with astonishing image sharpness - try the FocusStacker app. Now it's remarkably easy to achieve consistently excellent results when using the focus stacking technique in landscape and architectural photography.