We have seen in the previous post how the radius for deconvolution capture sharpening by a Gaussian PSF can be estimated for a given setup in well behaved and characterized camera systems. Some parameters like pixel aperture and AA strength should remain stable for a camera/prime lens combination as f-numbers are increased (aperture is decreased) from about f/5.6 on up – the f/stops dear to Full Frame landscape photographers. But how should the radius for generic Gaussian deconvolution change as the f-number increases from there? Continue reading Deconvolution PSF Changes with Aperture
What Radius to Use for Deconvolution Capture Sharpening
The following approach will work if you know the spatial frequency at which a certain MTF relative energy level (e.g. MTF50) is achieved by your camera/lens combination as set up at the time that the capture was taken.
The process by which our hardware captures images and stores them in the raw data inevitably blurs detail information from the scene. Continue reading What Radius to Use for Deconvolution Capture Sharpening
Deconvolution vs USM Capture Sharpening
UnSharp Masking (USM) capture sharpening is somewhat equivalent to taking a black/white marker and drawing along every transition in the picture to make it stand out more – automatically. Line thickness and darkness is chosen arbitrarily to achieve the desired effect, much like painters do. Continue reading Deconvolution vs USM Capture Sharpening
What Is Exposure
When capturing a typical photograph, light from one or more sources is reflected from the scene, reaches the lens, goes through it and eventually hits the sensing plane.
In photography Exposure is the quantity of visible light per unit area incident on the image plane during the time that it is exposed to the scene. Exposure is intuitively proportional to Luminance from the scene 
and exposure time 
. It is inversely proportional to lens f-number 
squared because it determines the relative size of the cone of light captured from the scene. You can read more about the theory in the article on angles and the Camera Equation.