Hi, everyone:

In view of the high prices of new LF lenses, it is always tempting to try the us ed market, despite uncertainties about the past history of a given lens (e.g.was it ever dropped?) and the absence of the warranty that would normally come with new product. The particular lenses I have in mind are pre-owned models of lens es in current production by Schneider, Rodenstock, Nikon, Fuji. My problem is k nowing a good (or not so good) used lens when I see one. Two questions:

1)At the place of purchase, say a camera store showroom, what are some visual te sts that can be performed? Let's assume that I have my LF camera, appropriate l ens board, etc. with me.

2) After purchase, on the assumption of a trial period of a few days, what are s ome diagnostic shooting tests that might quickly reveal problems not apparent at the time of purchase?

Any responses will be gratefully appreciated. All the best, Nick.