While searching for a good scanner especially for excellent photo results, you may have heard the terms Dmax, Dmin, or dynamic range.
Here in this article, we will discuss what is Dmax and Dmin and why they should be considered well before buying a scanner, especially for photographs.
What is Dynamic Range?
Your search for what is Dmax and Dmin must have certainly led you to a term called dynamic range.
You might have heard that a better dynamic range means better photographic results in a digital camera or a scanner.
Actually on the very basic level both a digital camera and a scanner work alike. Both are used to capture the illuminated image, mostly through CCD sensors and convert the details recorded as digital data.
The dynamic range of a camera or scanner is its ability to capture details in pure black and white. Dynamic range is the difference between Dmax and Dmin. Let’s have a look at what Dmax and Dmin are.
What Is Dmax and Dmin?
Simply put Dmax is the highest density that could be captured by a scanner. Dmin is its opposite; it’s the lowest density that a scanner could capture.
Image density can be measured with an image’s brightness and shadows. It ranges from 0.0 to 4.0. 4 being the maximum number is pure black while 0 is pure white. The minimum and maximum value of density that a scanner is capable of capturing are called its Dmax and Dmin range.
The Dynamic Range of imagery sensors depends on Dmax and Dmin. It is simply the difference between a scanner’s Dmax and Dmin.
For example, the sensor has a Dmax of 3.1 and Dmin 0.2, the dynamic range will be 2.9. Greater dynamic range gives better scanning results of photographs. More information is captured from the negatives, and less noise covers the fine details in the darkness.
The scanner’s ability to capture an image depends on its ability to register tone values that range from pure light to the pure dark. If the scanner does not have enough dynamic range, the minute details can be lost in white and black colors.
The higher dynamic range extends the signal in low black level and reduces noise.
Noise is the grainy veil in a photograph that obscures the details in a picture. Printed images don’t have much image than 1.9 Dmax.