Please pardon my ignorance here: are there two separate motors in Nikon AF bodies - one for autofocusing and the other for film transport OR there is only one motor with approprite gears to perform both functions?

I am particularly curious because the newly announced N80 body has a continuos film advance speed of 2.5fps while that figure for N70 is 3.7fps. If there is only one motor, then it could mean slower autofocus speed with the N80 (compared to N70) though the N80 does focus detection and lens movement in parallel (I do not think the N70 does that). Thanks in advance.

-- Suhbasis Laha (slaha@lucent.com), February 03, 2000

Answers

There almost has to be at least two in the body. Film transport and AF make different demands on the motor and control system, and they also have to work independently. The N80 is based on the N60 chassis which accounts for the slower transport speed. Regardless of the design details, I can't imagine introducing a camera with slower AF than the model it was replacing. Nikon has probably determined that fast AF is more important, to most people, than fast film transport.

-- Bruce Rubenstein (brubenstein@lucent.com), February 03, 2000.

Although N60 and N80 has similarly inadaquate meter coupling, the differences in weight, dimension, and changes to internal arrangement dictated by the big differnce in sizes AF condensor lenses and AF modules suggests N80 is not built on the N60 chassis. It looks like a entirely new chassis to me.

-- chuck fan (CHAOHUI@MSN.COM), February 03, 2000.

The F4 and F5 have four motors in the bodies, film advance, film rewind, focus, and shutter charging. I don't know the number in the N-series bodies.

-- Paul Staton (pstaton@houston.rr.com), February 04, 2000.