On too many binoculars, however, the slightest bump undoes the adjustment. A ring must be pulled or a knob pushed before the diopter adjustment will move. A small but valuable improvement. In the past, high quality optics have too often been a pain in the neck. This shaves over three ounces off the carry weight of the Swarovski 10x42 SLC and makes it 7 oz.
Birders love close focus.
We often study birds up close, and when birds aren't available many of us watch butterflies. Close focus varies from person to person through binoculars just as it does with the naked eye. So the distance that the manufacturer quotes is at best a guideline. To determine true close focus, you have to try the binoculars with your own eyes. All these can focus as close as 8 feet or closer.