A method of capturing a focused image of a continuously moving slide/objective arrangement is provided. A frame grabber device is triggered to capture an image of the slide through an objective at a first focus level as the slide continuously moves laterally relative to the objective. Alternatingly with triggering the frame grabber device, the objective is triggered to move to a second focus level after capture of the image of the slide. The objective moves in discrete steps, oscillating between minimum and maximum focus levels. The frame grabber device is triggered at a frequency as the slide continuously moves laterally relative to the objective so multiple images at different focus levels overlap, whereby a slide portion is common to each. The image having the maximum contrast value within overlapping images represents an optimum focus level for the slide portion, and thus the focused image. Associated apparatuses and methods are also provided.