I've tried to improve this solution in several ways. Now resulting image has right proportions.
Set sheet = ActiveSheet
output = "D:\SavedRange4.png"
zoom_coef = 100 / sheet.Parent.Windows(1).Zoom
Set area = sheet.Range(sheet.PageSetup.PrintArea)
area.CopyPicture xlPrinter
Set chartobj = sheet.ChartObjects.Add(0, 0, area.Width * zoom_coef, area.Height * zoom_coef)
chartobj.Chart.Paste
chartobj.Chart.Export output, "png"
chartobj.Delete