image circle and movements

I am looking at buying my first wide angle lens for my 4x5. I noticed that Niko n has two different 90mm's. One is a 4.5 and the other is an f/8. Both of them have what appears to be the same image circle of 235mm. Is this correct? I re alize that brightness is different but for right now price has to be my biggest concern. This may sound like a silly question but I would assume that the image circles would be different, however here that does not seem to be the case. Th ank as always for all the help. RJ

Russell: Unlike Schneider and Rodenstock, Nikon uses an 8 element formula for their slower (f/8) lens series, and so it is true that both Nikkor 90s have the same image circle.

And the f/8 is much lighter -- a heck of a lens for the price in my opinion -- and a bit of a darling among the landscape/backpacking set. It has great capacity for movement for the reasons Glenn noted.

If my memory serves me correctly, the 235mm circle is at f/22 with the f/8 lens and at f/16 with the f/4.5 lens. So the f/4.5 lens is a stop ahead on coverage, but both lenses offer a more than adequate range of movement anyway. The Nikon large format lenses are all very good, and image quality is not likely to differ much between the two. If most of your work is done in good light, why not settle for the f/8?