(Ron) wrote:
Is it practical to consider using older Nikon AIS manual-focus lenses
with a D40?

The light meter won't work properly, which means you are
forced to use a more accurate but slower method: either
the Histogram or the Highlight display. Which are fine
as long as you don't need fast adjustments. If you can
always shoot two or three shots as you manually adjust,
it's more accurate than the lightmeter anyway. If the
light is changing as you shoot and you cannot re-stage
each shot, it just won't get it.

You will probably also find focusing to be
uncomfortable. The electronic indicator will show you
when it is in focus, but manual focusing on the
viewfinder screen is not easy, and moving your eye from
the image to the indicator is distracting.

In short, if you are buying a camera and that is one
possible way you'll use it, a D40 is not the way to go.
If you have a D40 and want to try out some of those old
inexpensive Ai-S lenses, go for it, but don't expect
perfection (the most significant effect will most likely
be either to convince you of the need for a different
camera, or a different lense).

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)