I think the difference is the matrix metering. Nikon made a really big deal out of that when it was introduced.
- Leigh
FA also adds program shooting mode. It needs an AIS lens to work properly & shifts into a high speed program when anything longer that a 135mm lens is put on it (IIRC?). I bought an FA new back in 1986 & have been very happy with it. I have had no problems with it beyond the foam needing to be replaced.
I have an FE2 as well, picking one up cheap off of ebay a few years back. Out of the two I much prefer to use the FA. Two things that swing it for me are having an MD15 attached to the FA so find that it handles better & I prefer the LCD to a needle in the viewfinder. I also much prefer the FM2's LED viewfinder to the FE2's needle.
........I had to do the seals & the mirror bumper foam on my FA a few years ago & it is very easy to do yourself with a kit from Jon Goodman/Interslice.
