I'd also like to call on the collective wisdom of this group regarding the actual usable coverage of the 600mm and 750mm APO Germinars. Thanks to Arne and his excellent articles on these lenses I know what the official specs are. I know that based on these specs the 600mm will cover 7x17 with some left over for movements, but just miss the corners of 8x20 and that the 750mm should cover 12x20 with about an inch or so left over for front rise/shift. However, it has been my experience with other lenses originally targeted at the demanding reprographics industry (APO Artars, APO Ronars, G Clarons, etc.) that the official specs are often very conservative. Those using these lenses for pictorial use (usually involving some type of contact printing) often find they cover considerably more than the official spec would indicate.
So, if anyone has any first hand knowledge of the actual usable coverage of the 600mm and 750mm APO Germinars, please share your experiences here.