View Full Version : Image Circle Question

Rick Olson
8-Jan-2007, 08:34
Hi all,

I am looking to put together a ULF kit (7 x 17) and looking at lenses in the 300-400mm range. Based on recent discussions here, I am thinking about a 355mm G-Claron or a standard plasmat in the 360mm range. My question is about the image circle these lenses produce. Considering that the G-Claron has an image circle at 440mm +/- at f 22 and a typical plasmat (let's say a Nikkor 360mm 6.5) at 490mm +/- at f 22, can I expect the image circles to enlarge at the same factor for each of these lenses as they are stopped down, or does the design of the G-Claron allow the image circle to enlarge at a greater percentage than the Nikkor? I am looking for a lens that will allow the possibility of generous movements of the front standard (if needed). I know the Nikkor is a much larger and heavier lens but I am looking at the benefits of a brighter screen to focus and getting a workout carrying the camera!