Exploring Digital Zoom in Scanning Electron Microscopy

The concept of zoom in scanning electron microscopy (SEM) once referred to increasing the magnification of the sample by reducing the scanned field size. However, with the introduction of digital technology, the concept of zooming has become a little more complicated. Historically, older SEMs operated at a 512 × 512-pixel lateral resolution (262 kB pixel density) at TV scan rates. Today's newest SEMs can achieve up to 32k × 24k (4:3 ratio) pixel lateral resolution, equating to an 805 MB pixel density. In this article, we explore the factors involved in selecting an appropriate frame grabber size for SEM imaging. Specifically, we will delve into the implications of pixel density, including its impact on digital zoom capabilities, image file sizes, and overall image acquisition times.