I've been looking at possible solutions for making a longer lens work with my F&S 7x17. The front standard has been modified to take Sinar lens boards. Wouldn't it be possible to take a recessed Sinar lens board and reverse it as a means of allowing a 450mm lens to focus at less than infinity? I would expect that this would have some impact on movements, but I don't think that this would be a major issue. Any downside that I'm missing here?

Thanks,

Ed