On 17 Aug 1998 13:37:36 GMT, karwick@worldnet.att.net (B. Karwick) wrote:

>I would like to own a 500mm Nikkor f4 and prefer the idea of buying used. Is
>this too risky? If buying from a private party is a brief visual inspection
>enough?

With long, fast Nikkors, all are sharp to the corners wide open,
unless defective/damaged. A common defect (though with little
practical disadvantage for most people) is a slight tilt in the
focus plane compared with the film plane (this can be spotted
by carefully comparing the focus of a very distant object in
all four corners of the frame, and at opposite sides of the frame
in the viewfinder). A film check of the same thing is more positive,
and comparing corner sharpness with the center can only be done
on film (I have never seen a problem with this in checking quite
a few long Nikkors...). If the focus checks out OK, and there
is no "slop" (MF models only...) in the focus, and the infinity
mark is fairly close to correct infinity focus, and the diaphragm is
not sticky, and all glass is clear, clean, and free of fungus
tendrils or fog, go further... (Nikon will make major repairs to
the big ED lenses for a flat, surprisingly reasonable price...)

>Is shop testing (alignment) important?

No! This is generally a waste of money.

>What are the odds that a lens
>that looks OK and seems operational will contain hidden problems that I will
>regret for years?

Unlikely, if you have done a few simple tests, outlined above...

>Is buying from a shop a reasonable/necessary solution?

No - but I would only buy from anyone if there is a return OK
within a short time (long enough to allow checking the lens on film).

>PS I am leaning toward the 500 because it is still quite a bit smaller and
>lighter than the 600 and I am hoping that the utility of the extra 100mm
>outweighs the additional speed of the 400.

Alternatives: 300mm f2.8 + TC14/B/C - TC300/1; 400mm f3.5 +
TC14/B/C - TC300/1; and 600mm f4 or f5.6. If you know you want
the length of the 500mm, it is a good way to go...