I'm thinking of using a lens of maybe 180 or 210 mm focal length with my 8 x 10 to do macro work, > 1:1. These lenses normally won't cover the 8 x 10 format bu t it seems to me that if I use them at a longer extension for the close up work they will cover just fine since the image circle should expand to fit. The reas on for thinking of this is the expense of a normal 4 x 5 lens vs. that for 8 x 1 0. Can anyone think of a reason why this is a bad idea? I know I'm asking for s ome long exposure times but most of the work would be indoors in pretty calm and stable conditions.